WIP

This reverts commit e699513036.

.dockerignore

@@ -0,0 +1,9 @@
+# Ignore hidden files
+.*
+
+# Include .git for build version information
+!.git
+
+# Not needed for building
+AddMigration.*
+*.DotSettings.user

.run/Agent 1.run.xml

@@ -1,18 +1,18 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Agent 1" type="DotNetProject" factoryName=".NET Project">
-    <option name="EXE_PATH" value="$PROJECT_DIR$/Agent/Phantom.Agent/bin/Debug/net7.0/Phantom.Agent.exe" />
+    <option name="EXE_PATH" value="$PROJECT_DIR$/.artifacts/bin/Phantom.Agent/debug/Phantom.Agent.exe" />
     <option name="PROGRAM_PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Agent1" />
     <option name="PASS_PARENT_ENVS" value="1" />
     <envs>
+      <env name="AGENT_KEY" value="JXBQQYG5T267RQS75MXWBTCJZY5CKTCCGQY22MCZPHSQQSJYCHH2NG2TCNXQY6TBSXM9NQDRS2CMX" />
       <env name="AGENT_NAME" value="Agent 1" />
       <env name="ALLOWED_RCON_PORTS" value="25575,27000,27001" />
       <env name="ALLOWED_SERVER_PORTS" value="25565,26000,26001" />
+      <env name="CONTROLLER_HOST" value="localhost" />
       <env name="JAVA_SEARCH_PATH" value="~/.jdks" />
       <env name="MAX_INSTANCES" value="3" />
       <env name="MAX_MEMORY" value="12G" />
-      <env name="SERVER_AUTH_TOKEN_FILE" value="./secrets/agent.token" />
-      <env name="SERVER_HOST" value="localhost" />
     </envs>
     <option name="USE_EXTERNAL_CONSOLE" value="0" />
     <option name="USE_MONO" value="0" />
@@ -22,7 +22,7 @@
     <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
     <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="0" />
     <option name="PROJECT_KIND" value="DotNetCore" />
-    <option name="PROJECT_TFM" value="net7.0" />
+    <option name="PROJECT_TFM" value="net8.0" />
     <method v="2">
       <option name="Build" />
     </method>

.run/Agent 2.run.xml

@@ -1,18 +1,18 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Agent 2" type="DotNetProject" factoryName=".NET Project">
-    <option name="EXE_PATH" value="$PROJECT_DIR$/Agent/Phantom.Agent/bin/Debug/net7.0/Phantom.Agent.exe" />
+    <option name="EXE_PATH" value="$PROJECT_DIR$/.artifacts/bin/Phantom.Agent/debug/Phantom.Agent.exe" />
     <option name="PROGRAM_PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Agent2" />
     <option name="PASS_PARENT_ENVS" value="1" />
     <envs>
+      <env name="AGENT_KEY" value="JXBQQYG5T267RQS75MXWBTCJZY5CKTCCGQY22MCZPHSQQSJYCHH2NG2TCNXQY6TBSXM9NQDRS2CMX" />
       <env name="AGENT_NAME" value="Agent 2" />
       <env name="ALLOWED_RCON_PORTS" value="27002-27006" />
       <env name="ALLOWED_SERVER_PORTS" value="26002-26006" />
+      <env name="CONTROLLER_HOST" value="localhost" />
       <env name="JAVA_SEARCH_PATH" value="~/.jdks" />
       <env name="MAX_INSTANCES" value="5" />
       <env name="MAX_MEMORY" value="10G" />
-      <env name="SERVER_AUTH_TOKEN_FILE" value="./secrets/agent.token" />
-      <env name="SERVER_HOST" value="localhost" />
     </envs>
     <option name="USE_EXTERNAL_CONSOLE" value="0" />
     <option name="USE_MONO" value="0" />
@@ -22,7 +22,7 @@
     <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
     <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="0" />
     <option name="PROJECT_KIND" value="DotNetCore" />
-    <option name="PROJECT_TFM" value="net7.0" />
+    <option name="PROJECT_TFM" value="net8.0" />
     <method v="2">
       <option name="Build" />
     </method>

.run/Agent 3.run.xml

@@ -1,18 +1,18 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Agent 3" type="DotNetProject" factoryName=".NET Project">
-    <option name="EXE_PATH" value="$PROJECT_DIR$/Agent/Phantom.Agent/bin/Debug/net7.0/Phantom.Agent.exe" />
+    <option name="EXE_PATH" value="$PROJECT_DIR$/.artifacts/bin/Phantom.Agent/debug/Phantom.Agent.exe" />
     <option name="PROGRAM_PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Agent3" />
     <option name="PASS_PARENT_ENVS" value="1" />
     <envs>
+      <env name="AGENT_KEY" value="JXBQQYG5T267RQS75MXWBTCJZY5CKTCCGQY22MCZPHSQQSJYCHH2NG2TCNXQY6TBSXM9NQDRS2CMX" />
       <env name="AGENT_NAME" value="Agent 3" />
       <env name="ALLOWED_RCON_PORTS" value="27007" />
       <env name="ALLOWED_SERVER_PORTS" value="26007" />
+      <env name="CONTROLLER_HOST" value="localhost" />
       <env name="JAVA_SEARCH_PATH" value="~/.jdks" />
       <env name="MAX_INSTANCES" value="1" />
       <env name="MAX_MEMORY" value="2560M" />
-      <env name="SERVER_AUTH_TOKEN_FILE" value="./secrets/agent.token" />
-      <env name="SERVER_HOST" value="localhost" />
     </envs>
     <option name="USE_EXTERNAL_CONSOLE" value="0" />
     <option name="USE_MONO" value="0" />
@@ -22,7 +22,7 @@
     <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
     <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="0" />
     <option name="PROJECT_KIND" value="DotNetCore" />
-    <option name="PROJECT_TFM" value="net7.0" />
+    <option name="PROJECT_TFM" value="net8.0" />
     <method v="2">
       <option name="Build" />
     </method>

.run/Compile Bootstrap.run.xml

@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Compile Bootstrap" type="js.build_tools.npm">
-    <package-json value="$PROJECT_DIR$/Server/Phantom.Server.Web.Bootstrap/package.json" />
+    <package-json value="$PROJECT_DIR$/Web/Phantom.Web.Bootstrap/package.json" />
     <command value="run" />
     <scripts>
       <script value="compile" />
@@ -9,4 +9,4 @@
     <envs />
     <method v="2" />
   </configuration>
-</component>
+</component>

.run/Controller + Web + Agent x3.run.xml

@@ -1,9 +1,10 @@
 <component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="Server + Agent x3" type="CompoundRunConfigurationType">
+  <configuration default="false" name="Controller + Web + Agent x3" type="CompoundRunConfigurationType">
     <toRun name="Agent 1" type="DotNetProject" />
     <toRun name="Agent 2" type="DotNetProject" />
     <toRun name="Agent 3" type="DotNetProject" />
-    <toRun name="Server" type="DotNetProject" />
+    <toRun name="Controller" type="DotNetProject" />
+    <toRun name="Web" type="DotNetProject" />
     <method v="2" />
   </configuration>
-</component>
+</component>

.run/Controller + Web + Agent.run.xml

@@ -0,0 +1,8 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Controller + Web + Agent" type="CompoundRunConfigurationType">
+    <toRun name="Agent 1" type="DotNetProject" />
+    <toRun name="Controller" type="DotNetProject" />
+    <toRun name="Web" type="DotNetProject" />
+    <method v="2" />
+  </configuration>
+</component>

.run/Controller.run.xml

@@ -1,30 +1,29 @@
 <component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="Server" type="DotNetProject" factoryName=".NET Project">
-    <option name="EXE_PATH" value="$PROJECT_DIR$/Server/Phantom.Server/bin/Debug/net7.0/Phantom.Server.exe" />
+  <configuration default="false" name="Controller" type="DotNetProject" factoryName=".NET Project">
+    <option name="EXE_PATH" value="$PROJECT_DIR$/.artifacts/bin/Phantom.Controller/debug/Phantom.Controller.exe" />
     <option name="PROGRAM_PARAMETERS" value="" />
-    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Server" />
+    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Controller" />
     <option name="PASS_PARENT_ENVS" value="1" />
     <envs>
-      <env name="ASPNETCORE_ENVIRONMENT" value="Development" />
+      <env name="AGENT_RPC_SERVER_HOST" value="localhost" />
       <env name="PG_DATABASE" value="postgres" />
       <env name="PG_HOST" value="localhost" />
       <env name="PG_PASS" value="development" />
-      <env name="PG_PORT" value="9402" />
+      <env name="PG_PORT" value="9403" />
       <env name="PG_USER" value="postgres" />
-      <env name="RPC_SERVER_HOST" value="localhost" />
-      <env name="WEB_SERVER_HOST" value="localhost" />
+      <env name="WEB_RPC_SERVER_HOST" value="localhost" />
     </envs>
     <option name="USE_EXTERNAL_CONSOLE" value="0" />
     <option name="USE_MONO" value="0" />
     <option name="RUNTIME_ARGUMENTS" value="" />
-    <option name="PROJECT_PATH" value="$PROJECT_DIR$/Server/Phantom.Server/Phantom.Server.csproj" />
+    <option name="PROJECT_PATH" value="$PROJECT_DIR$/Controller/Phantom.Controller/Phantom.Controller.csproj" />
     <option name="PROJECT_EXE_PATH_TRACKING" value="1" />
     <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
     <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="0" />
     <option name="PROJECT_KIND" value="DotNetCore" />
-    <option name="PROJECT_TFM" value="net7.0" />
+    <option name="PROJECT_TFM" value="net8.0" />
     <method v="2">
       <option name="Build" />
     </method>
   </configuration>
-</component>
+</component>

.run/Server + Agent.run.xml

@@ -1,7 +0,0 @@
-<component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="Server + Agent" type="CompoundRunConfigurationType">
-    <toRun name="Agent 1" type="DotNetProject" />
-    <toRun name="Server" type="DotNetProject" />
-    <method v="2" />
-  </configuration>
-</component>

.run/Web.run.xml

@@ -0,0 +1,26 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Web" type="DotNetProject" factoryName=".NET Project">
+    <option name="EXE_PATH" value="$PROJECT_DIR$/.artifacts/bin/Phantom.Web/debug/Phantom.Web.exe" />
+    <option name="PROGRAM_PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Web" />
+    <option name="PASS_PARENT_ENVS" value="1" />
+    <envs>
+      <env name="ASPNETCORE_ENVIRONMENT" value="Development" />
+      <env name="CONTROLLER_HOST" value="localhost" />
+      <env name="WEB_KEY" value="BMNHM9RRPMCBBY29D9XHS6KBKZSRY7F5XFN27YZX96XXWJC2NM2D6YRHM9PZN9JGQGCSJ6FMB2GGZ" />
+      <env name="WEB_SERVER_HOST" value="localhost" />
+    </envs>
+    <option name="USE_EXTERNAL_CONSOLE" value="0" />
+    <option name="USE_MONO" value="0" />
+    <option name="RUNTIME_ARGUMENTS" value="" />
+    <option name="PROJECT_PATH" value="$PROJECT_DIR$/Web/Phantom.Web/Phantom.Web.csproj" />
+    <option name="PROJECT_EXE_PATH_TRACKING" value="1" />
+    <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
+    <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="0" />
+    <option name="PROJECT_KIND" value="DotNetCore" />
+    <option name="PROJECT_TFM" value="net8.0" />
+    <method v="2">
+      <option name="Build" />
+    </method>
+  </configuration>
+</component>

.workdir/.gitignore

@@ -1,2 +0,0 @@
-/Agent*/data
-/Agent*/temp

.workdir/Agent1/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

.workdir/Agent1/secrets/agent.key

@@ -1 +0,0 @@
-tLkn<EFBFBD>Z<EFBFBD><EFBFBD>}ы<><D18B>|~2<><32>><3E><>р<EFBFBD><D180>O*<2A>	p

.workdir/Agent1/secrets/agent.token

@@ -1 +0,0 @@
-TH7Z2MJKMR975N6HFBKQP9WQFMWWN5

.workdir/Agent2/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

.workdir/Agent2/secrets/agent.key

@@ -1 +0,0 @@
-tLkn<EFBFBD>Z<EFBFBD><EFBFBD>}ы<><D18B>|~2<><32>><3E><>р<EFBFBD><D180>O*<2A>	p

.workdir/Agent2/secrets/agent.token

@@ -1 +0,0 @@
-TH7Z2MJKMR975N6HFBKQP9WQFMWWN5

.workdir/Agent3/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

.workdir/Agent3/secrets/agent.key

@@ -1 +0,0 @@
-tLkn<EFBFBD>Z<EFBFBD><EFBFBD>}ы<><D18B>|~2<><32>><3E><>р<EFBFBD><D180>O*<2A>	p

.workdir/Agent3/secrets/agent.token

@@ -1 +0,0 @@
-TH7Z2MJKMR975N6HFBKQP9WQFMWWN5

.workdir/Controller/.gitignore

@@ -0,0 +1 @@
+

.workdir/Controller/secrets/agent.secret

@@ -0,0 +1 @@
+<EFBFBD>Z<EFBFBD>t<>MPI<49>GMZ<4D><5A><EFBFBD><EFBFBD>kN<6B>VF1X<><58>p

.workdir/Controller/secrets/web.key

@@ -0,0 +1,2 @@
+<EFBFBD><EFBFBD>h?Ο<05>Bx
+<02>

.workdir/Controller/secrets/web.secret

@@ -0,0 +1 @@
+T<EFBFBD>./g<11><>N<EFBFBD><4E>t<EFBFBD>$<24>!<21>(<28><>#<23>~<7E><>}<14><:

.workdir/Server/secrets/agent.key

@@ -1 +0,0 @@
-tLkn<EFBFBD>Z<EFBFBD><EFBFBD>}ы<><D18B>|~2<><32>><3E><>р<EFBFBD><D180>O*<2A>	p

.workdir/Server/secrets/agent.token

@@ -1 +0,0 @@
-TH7Z2MJKMR975N6HFBKQP9WQFMWWN5

.workdir/Server/secrets/secret.key

@@ -1 +0,0 @@
-+<2B><><EFBFBD><EFBFBD><<3C>f:<3A>bJ"e<18>׸ބ<D7B8><1F><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>

.workdir/Web/.gitignore

@@ -0,0 +1 @@
+/keys

AddMigration.bat

@@ -5,4 +5,4 @@ if [%1]==[] (
     exit
 )
 
-dotnet ef migrations add %~1 --project Server/Phantom.Server.Database.Postgres
+dotnet ef migrations add %~1 --project Controller/Phantom.Controller.Database.Postgres --msbuildprojectextensionspath .artifacts/obj/Phantom.Controller.Database.Postgres

AddMigration.sh

@@ -3,4 +3,4 @@ if [ -z "$1" ]; then
     exit 1
 fi
 
-dotnet ef migrations add "$1" --project Server/Phantom.Server.Database.Postgres
+dotnet ef migrations add "$1" --project Controller/Phantom.Controller.Database.Postgres --msbuildprojectextensionspath .artifacts/obj/Phantom.Controller.Database.Postgres

Agent/Phantom.Agent.Minecraft/Command/MinecraftCommand.cs

@@ -0,0 +1,15 @@
+namespace Phantom.Agent.Minecraft.Command;
+
+public static class MinecraftCommand {
+	public const string SaveOn = "save-on";
+	public const string SaveOff = "save-off";
+	public const string Stop = "stop";
+	
+	public static string Say(string message) {
+		return "say " + message;
+	}
+
+	public static string SaveAll(bool flush) {
+		return flush ? "save-all flush" : "save-all";
+	}
+}

Agent/Phantom.Agent.Minecraft/Instance/InstanceProcess.cs

@@ -1,23 +1,24 @@
-using System.Diagnostics;
-using Phantom.Utils.Collections;
+using Phantom.Utils.Collections;
+using Phantom.Utils.Processes;
 
-namespace Phantom.Agent.Minecraft.Instance; 
+namespace Phantom.Agent.Minecraft.Instance;
 
-public sealed class InstanceSession : IDisposable {
-	private readonly RingBuffer<string> outputBuffer = new (10000);
+public sealed class InstanceProcess : IDisposable {
+	public InstanceProperties InstanceProperties { get; }
+	
+	private readonly RingBuffer<string> outputBuffer = new (100);
 	private event EventHandler<string>? OutputEvent;
 
-	public event EventHandler? SessionEnded;
+	public event EventHandler? Ended;
 	public bool HasEnded { get; private set; }
 
 	private readonly Process process;
 
-	internal InstanceSession(Process process) {
+	internal InstanceProcess(InstanceProperties instanceProperties, Process process) {
+		this.InstanceProperties = instanceProperties;
 		this.process = process;
-		this.process.EnableRaisingEvents = true;
 		this.process.Exited += ProcessOnExited;
-		this.process.OutputDataReceived += HandleOutputLine;
-		this.process.ErrorDataReceived += HandleOutputLine;
+		this.process.OutputReceived += ProcessOutputReceived;
 	}
 
 	public async Task SendCommand(string command, CancellationToken cancellationToken) {
@@ -36,17 +37,15 @@ public sealed class InstanceSession : IDisposable {
 		OutputEvent -= listener;
 	}
 
-	private void HandleOutputLine(object sender, DataReceivedEventArgs args) {
-		if (args.Data is {} line) {
-			outputBuffer.Add(line);
-			OutputEvent?.Invoke(this, line);
-		}
+	private void ProcessOutputReceived(object? sender, Process.Output output) {
+		outputBuffer.Add(output.Line);
+		OutputEvent?.Invoke(this, output.Line);
 	}
 
 	private void ProcessOnExited(object? sender, EventArgs e) {
 		OutputEvent = null;
 		HasEnded = true;
-		SessionEnded?.Invoke(this, EventArgs.Empty);
+		Ended?.Invoke(this, EventArgs.Empty);
 	}
 
 	public void Kill() {
@@ -62,6 +61,6 @@ public sealed class InstanceSession : IDisposable {
 	public void Dispose() {
 		process.Dispose();
 		OutputEvent = null;
-		SessionEnded = null;
+		Ended = null;
 	}
 }

Agent/Phantom.Agent.Minecraft/Instance/InstanceProperties.cs

@@ -1,12 +1,17 @@
-using Phantom.Agent.Minecraft.Java;
+using System.Collections.Immutable;
+using Phantom.Agent.Minecraft.Java;
 using Phantom.Agent.Minecraft.Properties;
+using Phantom.Common.Data.Instance;
 
 namespace Phantom.Agent.Minecraft.Instance;
 
 public sealed record InstanceProperties(
+	Guid InstanceGuid,
 	Guid JavaRuntimeGuid,
 	JvmProperties JvmProperties,
+	ImmutableArray<string> JvmArguments,
 	string InstanceFolder,
 	string ServerVersion,
-	ServerProperties ServerProperties
+	ServerProperties ServerProperties,
+	InstanceLaunchProperties LaunchProperties
 );

Agent/Phantom.Agent.Minecraft/Java/JavaPropertiesFileEditor.cs

@@ -0,0 +1,92 @@
+using System.Text;
+using Kajabity.Tools.Java;
+
+namespace Phantom.Agent.Minecraft.Java;
+
+sealed class JavaPropertiesFileEditor {
+	private static readonly Encoding Encoding = Encoding.GetEncoding("ISO-8859-1");
+
+	private readonly Dictionary<string, string> overriddenProperties = new ();
+
+	public void Set(string key, string value) {
+		overriddenProperties[key] = value;
+	}
+
+	public async Task EditOrCreate(string filePath) {
+		if (File.Exists(filePath)) {
+			string tmpFilePath = filePath + ".tmp";
+			File.Copy(filePath, tmpFilePath, overwrite: true);
+			await EditFromCopyOrCreate(filePath, tmpFilePath);
+			File.Move(tmpFilePath, filePath, overwrite: true);
+		}
+		else {
+			await EditFromCopyOrCreate(null, filePath);
+		}
+	}
+
+	private async Task EditFromCopyOrCreate(string? sourceFilePath, string targetFilePath) {
+		var properties = new JavaProperties();
+
+		if (sourceFilePath != null) {
+			// TODO replace with custom async parser
+			await using var sourceStream = new FileStream(sourceFilePath, FileMode.Open, FileAccess.Read, FileShare.Read);
+			properties.Load(sourceStream, Encoding);
+		}
+
+		foreach (var (key, value) in overriddenProperties) {
+			properties[key] = value;
+		}
+
+		await using var targetStream = new FileStream(targetFilePath, FileMode.Create, FileAccess.Write, FileShare.Read);
+		await using var targetWriter = new StreamWriter(targetStream, Encoding);
+
+		await targetWriter.WriteLineAsync("# Properties");
+
+		foreach (var (key, value) in properties) {
+			await WriteProperty(targetWriter, key, value);
+		}
+	}
+
+	private static async Task WriteProperty(StreamWriter writer, string key, string value) {
+		await WritePropertyComponent(writer, key, escapeSpaces: true);
+		await writer.WriteAsync('=');
+		await WritePropertyComponent(writer, value, escapeSpaces: false);
+		await writer.WriteLineAsync();
+	}
+
+	private static async Task WritePropertyComponent(TextWriter writer, string component, bool escapeSpaces) {
+		for (int index = 0; index < component.Length; index++) {
+			var c = component[index];
+			switch (c) {
+				case '\\':
+				case '#':
+				case '!':
+				case '=':
+				case ':':
+				case ' ' when escapeSpaces || index == 0:
+					await writer.WriteAsync('\\');
+					await writer.WriteAsync(c);
+					break;
+				case var _ when c > 31 && c < 127:
+					await writer.WriteAsync(c);
+					break;
+				case '\t':
+					await writer.WriteAsync("\\t");
+					break;
+				case '\n':
+					await writer.WriteAsync("\\n");
+					break;
+				case '\r':
+					await writer.WriteAsync("\\r");
+					break;
+				case '\f':
+					await writer.WriteAsync("\\f");
+					break;
+				default:
+					await writer.WriteAsync("\\u");
+					await writer.WriteAsync(((int) c).ToString("X4"));
+					break;
+			}
+		}
+	}
+}

Agent/Phantom.Agent.Minecraft/Java/JavaRuntimeDiscovery.cs

@@ -7,7 +7,7 @@ using Serilog;
 namespace Phantom.Agent.Minecraft.Java;
 
 public sealed class JavaRuntimeDiscovery {
-	private static readonly ILogger Logger = PhantomLogger.Create(typeof(JavaRuntimeDiscovery));
+	private static readonly ILogger Logger = PhantomLogger.Create(nameof(JavaRuntimeDiscovery));
 
 	public static string? GetSystemSearchPath() {
 		const string LinuxJavaPath = "/usr/lib/jvm";
@@ -38,28 +38,38 @@ public sealed class JavaRuntimeDiscovery {
 			AttributesToSkip = FileAttributes.Hidden | FileAttributes.ReparsePoint | FileAttributes.System
 		}).Order()) {
 			var javaExecutablePath = Paths.NormalizeSlashes(Path.Combine(binFolderPath, javaExecutableName));
-			if (File.Exists(javaExecutablePath)) {
-				Logger.Information("Found candidate Java executable: {JavaExecutablePath}", javaExecutablePath);
-
-				JavaRuntime? foundRuntime;
-				try {
-					foundRuntime = await TryReadJavaRuntimeInformationFromProcess(javaExecutablePath);
-				} catch (OperationCanceledException) {
-					Logger.Error("Java process did not exit in time.");
-					continue;
-				} catch (Exception e) {
-					Logger.Error(e, "Caught exception while reading Java version information.");
-					continue;
-				}
-
-				if (foundRuntime == null) {
-					Logger.Error("Java executable did not output version information.");
-					continue;
-				}
-
-				Logger.Information("Found Java {DisplayName} at: {Path}", foundRuntime.DisplayName, javaExecutablePath);
-				yield return new JavaRuntimeExecutable(javaExecutablePath, foundRuntime);
+			
+			FileAttributes javaExecutableAttributes;
+			try {
+				javaExecutableAttributes = File.GetAttributes(javaExecutablePath);
+			} catch (Exception) {
+				continue;
 			}
+
+			if (javaExecutableAttributes.HasFlag(FileAttributes.ReparsePoint)) {
+				continue;
+			}
+
+			Logger.Information("Found candidate Java executable: {JavaExecutablePath}", javaExecutablePath);
+
+			JavaRuntime? foundRuntime;
+			try {
+				foundRuntime = await TryReadJavaRuntimeInformationFromProcess(javaExecutablePath);
+			} catch (OperationCanceledException) {
+				Logger.Error("Java process did not exit in time.");
+				continue;
+			} catch (Exception e) {
+				Logger.Error(e, "Caught exception while reading Java version information.");
+				continue;
+			}
+
+			if (foundRuntime == null) {
+				Logger.Error("Java executable did not output version information.");
+				continue;
+			}
+
+			Logger.Information("Found Java {DisplayName} at: {Path}", foundRuntime.DisplayName, javaExecutablePath);
+			yield return new JavaRuntimeExecutable(javaExecutablePath, foundRuntime);
 		}
 	}
 
@@ -69,10 +79,9 @@ public sealed class JavaRuntimeDiscovery {
 			WorkingDirectory = Path.GetDirectoryName(javaExecutablePath),
 			Arguments = "-XshowSettings:properties -version",
 			RedirectStandardInput = false,
-			RedirectStandardOutput = true,
+			RedirectStandardOutput = false,
 			RedirectStandardError = true,
-			UseShellExecute = false,
-			CreateNoWindow = false
+			UseShellExecute = false
 		};
 
 		var process = new Process { StartInfo = startInfo };

Agent/Phantom.Agent.Minecraft/Java/JavaRuntimeExecutable.cs

@@ -1,6 +1,6 @@
 using Phantom.Common.Data.Java;
 
-namespace Phantom.Agent.Minecraft.Java; 
+namespace Phantom.Agent.Minecraft.Java;
 
 public sealed class JavaRuntimeExecutable {
 	internal string ExecutablePath { get; }

Agent/Phantom.Agent.Minecraft/Java/JvmArgumentBuilder.cs

@@ -4,22 +4,27 @@ namespace Phantom.Agent.Minecraft.Java;
 
 sealed class JvmArgumentBuilder {
 	private readonly JvmProperties basicProperties;
-	private readonly List<string> customProperties = new ();
+	private readonly List<string> customArguments = new ();
 
 	public JvmArgumentBuilder(JvmProperties basicProperties) {
 		this.basicProperties = basicProperties;
 	}
 
+	public void Add(string argument) {
+		customArguments.Add(argument);
+	}
+
 	public void AddProperty(string key, string value) {
-		customProperties.Add("-D" + key + "=\"" + value + "\""); // TODO test quoting?
+		customArguments.Add("-D" + key + "=\"" + value + "\""); // TODO test quoting?
 	}
 
 	public void Build(Collection<string> target) {
-		target.Add("-Xms" + basicProperties.InitialHeapMegabytes + "M");
-		target.Add("-Xmx" + basicProperties.MaximumHeapMegabytes + "M");
-
-		foreach (var property in customProperties) {
+		foreach (var property in customArguments) {
 			target.Add(property);
 		}
+
+		// In case of duplicate JVM arguments, typically the last one wins.
+		target.Add("-Xms" + basicProperties.InitialHeapMegabytes + "M");
+		target.Add("-Xmx" + basicProperties.MaximumHeapMegabytes + "M");
 	}
 }

Agent/Phantom.Agent.Minecraft/Launcher/BaseLauncher.cs

@@ -1,66 +1,106 @@
-using System.Diagnostics;
-using System.Text;
-using Kajabity.Tools.Java;
+using System.Text;
 using Phantom.Agent.Minecraft.Instance;
 using Phantom.Agent.Minecraft.Java;
 using Phantom.Agent.Minecraft.Server;
+using Phantom.Utils.Processes;
+using Serilog;
 
 namespace Phantom.Agent.Minecraft.Launcher;
 
-public abstract class BaseLauncher {
+public abstract class BaseLauncher : IServerLauncher {
 	private readonly InstanceProperties instanceProperties;
 
+	protected string MinecraftVersion => instanceProperties.ServerVersion;
+
 	private protected BaseLauncher(InstanceProperties instanceProperties) {
 		this.instanceProperties = instanceProperties;
 	}
 
-	public async Task<LaunchResult> Launch(LaunchServices services, EventHandler<DownloadProgressEventArgs> downloadProgressEventHandler, CancellationToken cancellationToken) {
+	public async Task<LaunchResult> Launch(ILogger logger, LaunchServices services, EventHandler<DownloadProgressEventArgs> downloadProgressEventHandler, CancellationToken cancellationToken) {
 		if (!services.JavaRuntimeRepository.TryGetByGuid(instanceProperties.JavaRuntimeGuid, out var javaRuntimeExecutable)) {
 			return new LaunchResult.InvalidJavaRuntime();
 		}
 
-		var vanillaServerJarPath = await services.ServerExecutables.DownloadAndGetPath(instanceProperties.ServerVersion, downloadProgressEventHandler, cancellationToken);
+		var vanillaServerJarPath = await services.ServerExecutables.DownloadAndGetPath(instanceProperties.LaunchProperties.ServerDownloadInfo, MinecraftVersion, downloadProgressEventHandler, cancellationToken);
 		if (vanillaServerJarPath == null) {
 			return new LaunchResult.CouldNotDownloadMinecraftServer();
 		}
 
-		var startInfo = new ProcessStartInfo {
+		ServerJarInfo? serverJar;
+		try {
+			serverJar = await PrepareServerJar(logger, vanillaServerJarPath, cancellationToken);
+		} catch (OperationCanceledException) {
+			throw;
+		} catch (Exception e) {
+			logger.Error(e, "Caught exception while preparing the server jar.");
+			return new LaunchResult.CouldNotPrepareMinecraftServerLauncher();
+		}
+
+		if (!File.Exists(serverJar.FilePath)) {
+			logger.Error("Missing prepared server or launcher jar: {FilePath}", serverJar.FilePath);
+			return new LaunchResult.CouldNotPrepareMinecraftServerLauncher();
+		}
+
+		try {
+			await AcceptEula(instanceProperties);
+			await UpdateServerProperties(instanceProperties);
+		} catch (Exception e) {
+			logger.Error(e, "Caught exception while configuring the server.");
+			return new LaunchResult.CouldNotConfigureMinecraftServer();
+		}
+		
+		var processConfigurator = new ProcessConfigurator {
 			FileName = javaRuntimeExecutable.ExecutablePath,
 			WorkingDirectory = instanceProperties.InstanceFolder,
-			RedirectStandardInput = true,
-			RedirectStandardOutput = true,
-			RedirectStandardError = true,
-			UseShellExecute = false,
-			CreateNoWindow = false
+			RedirectInput = true,
+			UseShellExecute = false
 		};
-
-		var jvmArguments = new JvmArgumentBuilder(instanceProperties.JvmProperties);
-		CustomizeJvmArguments(jvmArguments);
-
-		var serverJarPath = await PrepareServerJar(vanillaServerJarPath, instanceProperties.InstanceFolder, cancellationToken);
-		var processArguments = startInfo.ArgumentList;
-		jvmArguments.Build(processArguments);
+		
+		var processArguments = processConfigurator.ArgumentList;
+		PrepareJvmArguments(serverJar).Build(processArguments);
 		processArguments.Add("-jar");
-		processArguments.Add(serverJarPath);
+		processArguments.Add(serverJar.FilePath);
 		processArguments.Add("nogui");
 
-		var process = new Process { StartInfo = startInfo };
-		var session = new InstanceSession(process);
+		var process = processConfigurator.CreateProcess();
+		var instanceProcess = new InstanceProcess(instanceProperties, process);
 
-		await AcceptEula(instanceProperties);
-		await UpdateServerProperties(instanceProperties);
+		try {
+			process.Start();
+		} catch (Exception launchException) {
+			logger.Error(launchException, "Caught exception launching the server process.");
+			
+			try {
+				process.Kill();
+			} catch (Exception killException) {
+				logger.Error(killException, "Caught exception trying to kill the server process after a failed launch.");
+			}
 
-		process.Start();
-		process.BeginOutputReadLine();
-		process.BeginErrorReadLine();
+			return new LaunchResult.CouldNotStartMinecraftServer();
+		}
 
-		return new LaunchResult.Success(session);
+		return new LaunchResult.Success(instanceProcess);
+	}
+
+	private JvmArgumentBuilder PrepareJvmArguments(ServerJarInfo serverJar) {
+		var builder = new JvmArgumentBuilder(instanceProperties.JvmProperties);
+
+		foreach (string argument in instanceProperties.JvmArguments) {
+			builder.Add(argument);
+		}
+
+		foreach (var argument in serverJar.ExtraArgs) {
+			builder.Add(argument);
+		}
+
+		CustomizeJvmArguments(builder);
+		return builder;
 	}
 
 	private protected virtual void CustomizeJvmArguments(JvmArgumentBuilder arguments) {}
 
-	private protected virtual Task<string> PrepareServerJar(string serverJarPath, string instanceFolderPath, CancellationToken cancellationToken) {
-		return Task.FromResult(serverJarPath);
+	private protected virtual Task<ServerJarInfo> PrepareServerJar(ILogger logger, string serverJarPath, CancellationToken cancellationToken) {
+		return Task.FromResult(new ServerJarInfo(serverJarPath));
 	}
 
 	private static async Task AcceptEula(InstanceProperties instanceProperties) {
@@ -69,19 +109,8 @@ public abstract class BaseLauncher {
 	}
 
 	private static async Task UpdateServerProperties(InstanceProperties instanceProperties) {
-		var serverPropertiesFilePath = Path.Combine(instanceProperties.InstanceFolder, "server.properties");
-		var serverPropertiesData = new JavaProperties();
-
-		try {
-			await using var readStream = new FileStream(serverPropertiesFilePath, FileMode.Open, FileAccess.Read, FileShare.Read);
-			serverPropertiesData.Load(readStream);
-		} catch (FileNotFoundException) {
-			// ignore
-		}
-		
-		instanceProperties.ServerProperties.SetTo(serverPropertiesData);
-
-		await using var writeStream = new FileStream(serverPropertiesFilePath, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None);
-		serverPropertiesData.Store(writeStream, true);
+		var serverPropertiesEditor = new JavaPropertiesFileEditor();
+		instanceProperties.ServerProperties.SetTo(serverPropertiesEditor);
+		await serverPropertiesEditor.EditOrCreate(Path.Combine(instanceProperties.InstanceFolder, "server.properties"));
 	}
 }

Agent/Phantom.Agent.Minecraft/Launcher/IServerLauncher.cs

@@ -0,0 +1,8 @@
+using Phantom.Agent.Minecraft.Server;
+using Serilog;
+
+namespace Phantom.Agent.Minecraft.Launcher;
+
+public interface IServerLauncher {
+	Task<LaunchResult> Launch(ILogger logger, LaunchServices services, EventHandler<DownloadProgressEventArgs> downloadProgressEventHandler, CancellationToken cancellationToken);
+}

Agent/Phantom.Agent.Minecraft/Launcher/LaunchResult.cs

@@ -5,9 +5,15 @@ namespace Phantom.Agent.Minecraft.Launcher;
 public abstract record LaunchResult {
 	private LaunchResult() {}
 
-	public sealed record Success(InstanceSession Session) : LaunchResult;
+	public sealed record Success(InstanceProcess Process) : LaunchResult;
 
 	public sealed record InvalidJavaRuntime : LaunchResult;
 
 	public sealed record CouldNotDownloadMinecraftServer : LaunchResult;
+	
+	public sealed record CouldNotPrepareMinecraftServerLauncher : LaunchResult;
+	
+	public sealed record CouldNotConfigureMinecraftServer : LaunchResult;
+	
+	public sealed record CouldNotStartMinecraftServer : LaunchResult;
 }

Agent/Phantom.Agent.Minecraft/Launcher/LaunchServices.cs

@@ -1,6 +1,6 @@
 using Phantom.Agent.Minecraft.Java;
 using Phantom.Agent.Minecraft.Server;
 
-namespace Phantom.Agent.Minecraft.Launcher; 
+namespace Phantom.Agent.Minecraft.Launcher;
 
 public sealed record LaunchServices(MinecraftServerExecutables ServerExecutables, JavaRuntimeRepository JavaRuntimeRepository);

Agent/Phantom.Agent.Minecraft/Launcher/ServerJarInfo.cs

@@ -0,0 +1,7 @@
+using System.Collections.Immutable;
+
+namespace Phantom.Agent.Minecraft.Launcher;
+
+sealed record ServerJarInfo(string FilePath, ImmutableArray<string> ExtraArgs) {
+	public ServerJarInfo(string filePath) : this(filePath, ImmutableArray<string>.Empty) {}
+}

Agent/Phantom.Agent.Minecraft/Launcher/Types/FabricLauncher.cs

@@ -0,0 +1,55 @@
+using System.Collections.Immutable;
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Utils.IO;
+using Serilog;
+
+namespace Phantom.Agent.Minecraft.Launcher.Types;
+
+public sealed class FabricLauncher : BaseLauncher {
+	public FabricLauncher(InstanceProperties instanceProperties) : base(instanceProperties) {}
+	
+	private protected override async Task<ServerJarInfo> PrepareServerJar(ILogger logger, string serverJarPath, CancellationToken cancellationToken) {
+		var serverJarParentFolderPath = Directory.GetParent(serverJarPath);
+		if (serverJarParentFolderPath == null) {
+			throw new ArgumentException("Could not get parent folder from: " + serverJarPath, nameof(serverJarPath));
+		}
+		
+		var launcherJarPath = Path.Combine(serverJarParentFolderPath.FullName, "fabric.jar");
+		
+		if (!File.Exists(launcherJarPath)) {
+			await DownloadLauncher(logger, launcherJarPath, cancellationToken);
+		}
+
+		return new ServerJarInfo(launcherJarPath, ImmutableArray.Create("-Dfabric.installer.server.gameJar=" + Paths.NormalizeSlashes(serverJarPath)));
+	}
+
+	private async Task DownloadLauncher(ILogger logger, string targetFilePath, CancellationToken cancellationToken) {
+		// TODO customizable loader version, probably with a dedicated temporary folder
+		string installerUrl = $"https://meta.fabricmc.net/v2/versions/loader/{MinecraftVersion}/stable/stable/server/jar";
+		logger.Information("Downloading Fabric launcher from: {Url}", installerUrl);
+		
+		using var http = new HttpClient();
+		
+		var response = await http.GetAsync(installerUrl, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
+		response.EnsureSuccessStatusCode();
+		
+		try {
+			await using var fileStream = new FileStream(targetFilePath, FileMode.CreateNew, FileAccess.Write, FileShare.Read);
+			await using var responseStream = await response.Content.ReadAsStreamAsync(cancellationToken);
+			await responseStream.CopyToAsync(fileStream, cancellationToken);
+		} catch (Exception) {
+			TryDeleteLauncherAfterFailure(logger, targetFilePath);
+			throw;
+		}
+	}
+
+	private static void TryDeleteLauncherAfterFailure(ILogger logger, string filePath) {
+		if (File.Exists(filePath)) {
+			try {
+				File.Delete(filePath);
+			} catch (Exception e) {
+				logger.Warning(e, "Could not clean up partially downloaded Fabric launcher: {FilePath}", filePath);
+			}
+		}
+	}
+}

Agent/Phantom.Agent.Minecraft/Launcher/Types/InvalidLauncher.cs

@@ -0,0 +1,14 @@
+using Phantom.Agent.Minecraft.Server;
+using Serilog;
+
+namespace Phantom.Agent.Minecraft.Launcher.Types;
+
+public sealed class InvalidLauncher : IServerLauncher {
+	public static InvalidLauncher Instance { get; } = new ();
+	
+	private InvalidLauncher() {}
+	
+	public Task<LaunchResult> Launch(ILogger logger, LaunchServices services, EventHandler<DownloadProgressEventArgs> downloadProgressEventHandler, CancellationToken cancellationToken) {
+		return Task.FromResult<LaunchResult>(new LaunchResult.CouldNotPrepareMinecraftServerLauncher());
+	}
+}

Agent/Phantom.Agent.Minecraft/Launcher/Types/VanillaLauncher.cs

@@ -1,6 +1,6 @@
 using Phantom.Agent.Minecraft.Instance;
 
-namespace Phantom.Agent.Minecraft.Launcher.Types; 
+namespace Phantom.Agent.Minecraft.Launcher.Types;
 
 public sealed class VanillaLauncher : BaseLauncher {
 	public VanillaLauncher(InstanceProperties instanceProperties) : base(instanceProperties) {}

Agent/Phantom.Agent.Minecraft/Phantom.Agent.Minecraft.csproj

@@ -1,21 +1,18 @@
 <Project Sdk="Microsoft.NET.Sdk">
   
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   
   <ItemGroup>
-    <PackageReference Include="Kajabity.Tools.Java" Version="0.3.7879.40798" />
+    <PackageReference Include="Kajabity.Tools.Java" />
   </ItemGroup>
   
   <ItemGroup>
     <ProjectReference Include="..\..\Common\Phantom.Common.Data\Phantom.Common.Data.csproj" />
     <ProjectReference Include="..\..\Common\Phantom.Common.Logging\Phantom.Common.Logging.csproj" />
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.Collections\Phantom.Utils.Collections.csproj" />
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.Cryptography\Phantom.Utils.Cryptography.csproj" />
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.IO\Phantom.Utils.IO.csproj" />
+    <ProjectReference Include="..\..\Utils\Phantom.Utils\Phantom.Utils.csproj" />
   </ItemGroup>
 
 </Project>

Agent/Phantom.Agent.Minecraft/Properties/MinecraftServerProperty.cs

@@ -1,6 +1,6 @@
-using Kajabity.Tools.Java;
+using Phantom.Agent.Minecraft.Java;
 
-namespace Phantom.Agent.Minecraft.Properties; 
+namespace Phantom.Agent.Minecraft.Properties;
 
 abstract class MinecraftServerProperty<T> {
 	private readonly string key;
@@ -12,7 +12,7 @@ abstract class MinecraftServerProperty<T> {
 	protected abstract T Read(string value);
 	protected abstract string Write(T value);
 
-	public void Set(JavaProperties properties, T value) {
-		properties.SetProperty(key, Write(value));
+	public void Set(JavaPropertiesFileEditor properties, T value) {
+		properties.Set(key, Write(value));
 	}
 }

Agent/Phantom.Agent.Minecraft/Properties/ServerProperties.cs

@@ -1,4 +1,4 @@
-using Kajabity.Tools.Java;
+using Phantom.Agent.Minecraft.Java;
 
 namespace Phantom.Agent.Minecraft.Properties;
 
@@ -7,7 +7,7 @@ public sealed record ServerProperties(
 	ushort RconPort,
 	bool EnableRcon = true
 ) {
-	internal void SetTo(JavaProperties properties) {
+	internal void SetTo(JavaPropertiesFileEditor properties) {
 		MinecraftServerProperties.ServerPort.Set(properties, ServerPort);
 		MinecraftServerProperties.RconPort.Set(properties, RconPort);
 		MinecraftServerProperties.EnableRcon.Set(properties, EnableRcon);

Agent/Phantom.Agent.Minecraft/Server/DownloadProgressEventArgs.cs

@@ -1,4 +1,4 @@
-namespace Phantom.Agent.Minecraft.Server; 
+namespace Phantom.Agent.Minecraft.Server;
 
 public sealed class DownloadProgressEventArgs : EventArgs {
 	public ulong DownloadedBytes { get; }

Agent/Phantom.Agent.Minecraft/Server/MinecraftServerExecutableDownloadListener.cs

@@ -1,3 +1,3 @@
-namespace Phantom.Agent.Minecraft.Server; 
+namespace Phantom.Agent.Minecraft.Server;
 
 sealed record MinecraftServerExecutableDownloadListener(EventHandler<DownloadProgressEventArgs> DownloadProgressEventHandler, CancellationToken CancellationToken);

Agent/Phantom.Agent.Minecraft/Server/MinecraftServerExecutableDownloader.cs

@@ -1,9 +1,9 @@
-using System.Net.Http.Json;
-using System.Security.Cryptography;
-using System.Text.Json;
+using System.Security.Cryptography;
+using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Logging;
 using Phantom.Utils.Cryptography;
 using Phantom.Utils.IO;
+using Phantom.Utils.Runtime;
 using Serilog;
 
 namespace Phantom.Agent.Minecraft.Server;
@@ -11,8 +11,6 @@ namespace Phantom.Agent.Minecraft.Server;
 sealed class MinecraftServerExecutableDownloader {
 	private static readonly ILogger Logger = PhantomLogger.Create<MinecraftServerExecutableDownloader>();
 
-	private const string VersionManifestUrl = "https://launchermeta.mojang.com/mc/game/version_manifest.json";
-
 	public Task<string?> Task { get; }
 	public event EventHandler<DownloadProgressEventArgs>? DownloadProgress;
 	public event EventHandler? Completed;
@@ -20,15 +18,15 @@ sealed class MinecraftServerExecutableDownloader {
 	private readonly CancellationTokenSource cancellationTokenSource = new ();
 	private int listeners = 0;
 
-	public MinecraftServerExecutableDownloader(string version, string filePath, MinecraftServerExecutableDownloadListener listener) {
+	public MinecraftServerExecutableDownloader(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath, MinecraftServerExecutableDownloadListener listener) {
 		Register(listener);
-		Task = DownloadAndGetPath(version, filePath);
+		Task = DownloadAndGetPath(fileDownloadInfo, minecraftVersion, filePath);
 		Task.ContinueWith(OnCompleted, TaskScheduler.Default);
 	}
 
 	public void Register(MinecraftServerExecutableDownloadListener listener) {
 		++listeners;
-		Logger.Verbose("Registered download listener, current listener count: {Listeners}", listeners);
+		Logger.Debug("Registered download listener, current listener count: {Listeners}", listeners);
 		
 		DownloadProgress += listener.DownloadProgressEventHandler;
 		listener.CancellationToken.Register(Unregister, listener);
@@ -39,11 +37,11 @@ sealed class MinecraftServerExecutableDownloader {
 		DownloadProgress -= listener.DownloadProgressEventHandler;
 
 		if (--listeners <= 0) {
-			Logger.Verbose("Unregistered last download listener, cancelling download.");
+			Logger.Debug("Unregistered last download listener, cancelling download.");
 			cancellationTokenSource.Cancel();
 		}
 		else {
-			Logger.Verbose("Unregistered download listener, current listener count: {Listeners}", listeners);
+			Logger.Debug("Unregistered download listener, current listener count: {Listeners}", listeners);
 		}
 	}
 
@@ -52,7 +50,7 @@ sealed class MinecraftServerExecutableDownloader {
 	}
 
 	private void OnCompleted(Task task) {
-		Logger.Verbose("Download task completed.");
+		Logger.Debug("Download task completed.");
 		Completed?.Invoke(this, EventArgs.Empty);
 		Completed = null;
 		DownloadProgress = null;
@@ -70,36 +68,26 @@ sealed class MinecraftServerExecutableDownloader {
 		}
 	}
 
-	private async Task<string?> DownloadAndGetPath(string version, string filePath) {
-		Logger.Information("Downloading server version {Version}...", version);
-
-		HttpClient http = new HttpClient();
+	private async Task<string?> DownloadAndGetPath(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath) {
 		string tmpFilePath = filePath + ".tmp";
 
 		var cancellationToken = cancellationTokenSource.Token;
 		try {
-			Logger.Information("Fetching version manifest from: {Url}", VersionManifestUrl);
-			var versionManifest = await FetchVersionManifest(http, cancellationToken);
-			var metadataUrl = GetVersionMetadataUrlFromManifest(version, versionManifest);
-
-			Logger.Information("Fetching metadata for version {Version} from: {Url}", version, metadataUrl);
-			var versionMetadata = await FetchVersionMetadata(http, metadataUrl, cancellationToken);
-			var serverExecutableInfo = GetServerExecutableUrlFromMetadata(versionMetadata);
-
-			Logger.Information("Downloading server executable from: {Url} ({Size})", serverExecutableInfo.DownloadUrl, serverExecutableInfo.Size.ToHumanReadable(decimalPlaces: 1));
+			Logger.Information("Downloading server version {Version} from: {Url} ({Size})", minecraftVersion, fileDownloadInfo.DownloadUrl, fileDownloadInfo.Size.ToHumanReadable(decimalPlaces: 1));
 			try {
-				await FetchServerExecutableFile(http, new DownloadProgressCallback(this), serverExecutableInfo, tmpFilePath, cancellationToken);
+				using var http = new HttpClient();
+				await FetchServerExecutableFile(http, new DownloadProgressCallback(this), fileDownloadInfo, tmpFilePath, cancellationToken);
 			} catch (Exception) {
 				TryDeleteExecutableAfterFailure(tmpFilePath);
 				throw;
 			}
 
 			File.Move(tmpFilePath, filePath, true);
-			Logger.Information("Server version {Version} downloaded.", version);
+			Logger.Information("Server version {Version} downloaded.", minecraftVersion);
 
 			return filePath;
 		} catch (OperationCanceledException) {
-			Logger.Information("Download for server version {Version} was cancelled.", version);
+			Logger.Information("Download for server version {Version} was cancelled.", minecraftVersion);
 			throw;
 		} catch (StopProcedureException) {
 			return null;
@@ -111,41 +99,17 @@ sealed class MinecraftServerExecutableDownloader {
 		}
 	}
 
-	private static async Task<JsonElement> FetchVersionManifest(HttpClient http, CancellationToken cancellationToken) {
-		try {
-			return await http.GetFromJsonAsync<JsonElement>(VersionManifestUrl, cancellationToken);
-		} catch (HttpRequestException e) {
-			Logger.Error(e, "Unable to download version manifest.");
-			throw StopProcedureException.Instance;
-		} catch (Exception e) {
-			Logger.Error(e, "Unable to parse version manifest as JSON.");
-			throw StopProcedureException.Instance;
-		}
-	}
-
-	private static async Task<JsonElement> FetchVersionMetadata(HttpClient http, string metadataUrl, CancellationToken cancellationToken) {
-		try {
-			return await http.GetFromJsonAsync<JsonElement>(metadataUrl, cancellationToken);
-		} catch (HttpRequestException e) {
-			Logger.Error(e, "Unable to download version metadata.");
-			throw StopProcedureException.Instance;
-		} catch (Exception e) {
-			Logger.Error(e, "Unable to parse version metadata as JSON.");
-			throw StopProcedureException.Instance;
-		}
-	}
-
-	private static async Task FetchServerExecutableFile(HttpClient http, DownloadProgressCallback progressCallback, ServerExecutableInfo info, string filePath, CancellationToken cancellationToken) {
+	private static async Task FetchServerExecutableFile(HttpClient http, DownloadProgressCallback progressCallback, FileDownloadInfo fileDownloadInfo, string filePath, CancellationToken cancellationToken) {
 		Sha1String downloadedFileHash;
 
 		try {
-			var response = await http.GetAsync(info.DownloadUrl, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
+			var response = await http.GetAsync(fileDownloadInfo.DownloadUrl, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
 			response.EnsureSuccessStatusCode();
 
 			await using var fileStream = new FileStream(filePath, FileMode.CreateNew, FileAccess.Write, FileShare.Read);
 			await using var responseStream = await response.Content.ReadAsStreamAsync(cancellationToken);
 
-			using var streamCopier = new MinecraftServerDownloadStreamCopier(progressCallback, info.Size.Bytes);
+			using var streamCopier = new MinecraftServerDownloadStreamCopier(progressCallback, fileDownloadInfo.Size.Bytes);
 			downloadedFileHash = await streamCopier.Copy(responseStream, fileStream, cancellationToken);
 		} catch (OperationCanceledException) {
 			throw;
@@ -154,8 +118,8 @@ sealed class MinecraftServerExecutableDownloader {
 			throw StopProcedureException.Instance;
 		}
 
-		if (!downloadedFileHash.Equals(info.Hash)) {
-			Logger.Error("Downloaded server executable has mismatched SHA1 hash. Expected {Expected}, got {Actual}.", info.Hash, downloadedFileHash);
+		if (!downloadedFileHash.Equals(fileDownloadInfo.Hash)) {
+			Logger.Error("Downloaded server executable has mismatched SHA1 hash. Expected {Expected}, got {Actual}.", fileDownloadInfo.Hash, downloadedFileHash);
 			throw StopProcedureException.Instance;
 		}
 	}
@@ -170,83 +134,6 @@ sealed class MinecraftServerExecutableDownloader {
 		}
 	}
 
-	private static string GetVersionMetadataUrlFromManifest(string serverVersion, JsonElement versionManifest) {
-		JsonElement versionsElement = GetJsonPropertyOrThrow(versionManifest, "versions", JsonValueKind.Array, "version manifest");
-		JsonElement versionElement;
-		try {
-			versionElement = versionsElement.EnumerateArray().Single(ele => ele.TryGetProperty("id", out var id) && id.ValueKind == JsonValueKind.String && id.GetString() == serverVersion);
-		} catch (Exception) {
-			Logger.Error("Version {Version} was not found in version manifest.", serverVersion);
-			throw StopProcedureException.Instance;
-		}
-
-		JsonElement urlElement = GetJsonPropertyOrThrow(versionElement, "url", JsonValueKind.String, "version entry in version manifest");
-		string? url = urlElement.GetString();
-
-		if (!Uri.TryCreate(url, UriKind.Absolute, out var uri)) {
-			Logger.Error("The \"url\" key in version entry in version manifest does not contain a valid URL: {Url}", url);
-			throw StopProcedureException.Instance;
-		}
-
-		if (uri.Scheme != "https" || !uri.AbsolutePath.EndsWith(".json", StringComparison.OrdinalIgnoreCase)) {
-			Logger.Error("The \"url\" key in version entry in version manifest does not contain a accepted URL: {Url}", url);
-			throw StopProcedureException.Instance;
-		}
-
-		return url;
-	}
-
-	private static ServerExecutableInfo GetServerExecutableUrlFromMetadata(JsonElement versionMetadata) {
-		JsonElement downloadsElement = GetJsonPropertyOrThrow(versionMetadata, "downloads", JsonValueKind.Object, "version metadata");
-		JsonElement serverElement = GetJsonPropertyOrThrow(downloadsElement, "server", JsonValueKind.Object, "downloads object in version metadata");
-		JsonElement urlElement = GetJsonPropertyOrThrow(serverElement, "url", JsonValueKind.String, "downloads.server object in version metadata");
-		string? url = urlElement.GetString();
-
-		if (!Uri.TryCreate(url, UriKind.Absolute, out var uri)) {
-			Logger.Error("The \"url\" key in downloads.server object in version metadata does not contain a valid URL: {Url}", url);
-			throw StopProcedureException.Instance;
-		}
-
-		if (uri.Scheme != "https" || !uri.AbsolutePath.EndsWith(".jar", StringComparison.OrdinalIgnoreCase)) {
-			Logger.Error("The \"url\" key in downloads.server object in version metadata does not contain a accepted URL: {Url}", url);
-			throw StopProcedureException.Instance;
-		}
-
-		JsonElement sizeElement = GetJsonPropertyOrThrow(serverElement, "size", JsonValueKind.Number, "downloads.server object in version metadata");
-		ulong size;
-		try {
-			size = sizeElement.GetUInt64();
-		} catch (FormatException) {
-			Logger.Error("The \"size\" key in downloads.server object in version metadata contains an invalid file size: {Size}", sizeElement);
-			throw StopProcedureException.Instance;
-		}
-
-		JsonElement sha1Element = GetJsonPropertyOrThrow(serverElement, "sha1", JsonValueKind.String, "downloads.server object in version metadata");
-		Sha1String hash;
-		try {
-			hash = Sha1String.FromString(sha1Element.GetString());
-		} catch (Exception) {
-			Logger.Error("The \"sha1\" key in downloads.server object in version metadata does not contain a valid SHA-1 hash: {Sha1}", sha1Element.GetString());
-			throw StopProcedureException.Instance;
-		}
-
-		return new ServerExecutableInfo(url, hash, new FileSize(size));
-	}
-
-	private static JsonElement GetJsonPropertyOrThrow(JsonElement parentElement, string propertyKey, JsonValueKind expectedKind, string location) {
-		if (!parentElement.TryGetProperty(propertyKey, out var valueElement)) {
-			Logger.Error("Missing \"{Property}\" key in " + location + ".", propertyKey);
-			throw StopProcedureException.Instance;
-		}
-
-		if (valueElement.ValueKind != expectedKind) {
-			Logger.Error("The \"{Property}\" key in " + location + " does not contain a JSON {ExpectedType}. Actual type: {ActualType}", propertyKey, expectedKind, valueElement.ValueKind);
-			throw StopProcedureException.Instance;
-		}
-
-		return valueElement;
-	}
-
 	private sealed class MinecraftServerDownloadStreamCopier : IDisposable {
 		private readonly StreamCopier streamCopier = new ();
 		private readonly IncrementalHash sha1 = IncrementalHash.CreateHash(HashAlgorithmName.SHA1);
@@ -278,10 +165,4 @@ sealed class MinecraftServerExecutableDownloader {
 			streamCopier.Dispose();
 		}
 	}
-
-	private sealed class StopProcedureException : Exception {
-		public static StopProcedureException Instance { get; } = new ();
-
-		private StopProcedureException() {}
-	}
 }

Agent/Phantom.Agent.Minecraft/Server/MinecraftServerExecutables.cs

@@ -1,13 +1,16 @@
 using System.Text.RegularExpressions;
+using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Logging;
+using Phantom.Utils.IO;
 using Serilog;
 
 namespace Phantom.Agent.Minecraft.Server;
 
-public sealed class MinecraftServerExecutables {
+public sealed partial class MinecraftServerExecutables {
 	private static readonly ILogger Logger = PhantomLogger.Create<MinecraftServerExecutables>();
 
-	private static readonly Regex VersionFolderSanitizeRegex = new (@"[^a-zA-Z0-9_\-\.]", RegexOptions.Compiled);
+	[GeneratedRegex(@"[^a-zA-Z0-9_\-\.]", RegexOptions.Compiled)]
+	private static partial Regex SanitizePathRegex();
 
 	private readonly string basePath;
 	private readonly Dictionary<string, MinecraftServerExecutableDownloader> runningDownloadersByVersion = new ();
@@ -16,16 +19,21 @@ public sealed class MinecraftServerExecutables {
 		this.basePath = basePath;
 	}
 
-	internal async Task<string?> DownloadAndGetPath(string version, EventHandler<DownloadProgressEventArgs> progressEventHandler, CancellationToken cancellationToken) {
-		string serverExecutableFolderPath = Path.Combine(basePath, VersionFolderSanitizeRegex.Replace(version, "_"));
+	internal async Task<string?> DownloadAndGetPath(FileDownloadInfo? fileDownloadInfo, string minecraftVersion, EventHandler<DownloadProgressEventArgs> progressEventHandler, CancellationToken cancellationToken) {
+		string serverExecutableFolderPath = Path.Combine(basePath, SanitizePathRegex().IsMatch(minecraftVersion) ? SanitizePathRegex().Replace(minecraftVersion, "_") : minecraftVersion);
 		string serverExecutableFilePath = Path.Combine(serverExecutableFolderPath, "server.jar");
 
 		if (File.Exists(serverExecutableFilePath)) {
 			return serverExecutableFilePath;
 		}
 
+		if (fileDownloadInfo == null) {
+			Logger.Error("Unable to download server executable for version {Version} because no download info was provided.", minecraftVersion);
+			return null;
+		}
+
 		try {
-			Directory.CreateDirectory(serverExecutableFolderPath);
+			Directories.Create(serverExecutableFolderPath, Chmod.URWX_GRX);
 		} catch (Exception e) {
 			Logger.Error(e, "Unable to create folder for server executable: {ServerExecutableFolderPath}", serverExecutableFolderPath);
 			return null;
@@ -35,19 +43,19 @@ public sealed class MinecraftServerExecutables {
 		MinecraftServerExecutableDownloadListener listener = new (progressEventHandler, cancellationToken);
 
 		lock (this) {
-			if (runningDownloadersByVersion.TryGetValue(version, out downloader)) {
-				Logger.Information("A download for server version {Version} is already running, waiting for it to finish...", version);
+			if (runningDownloadersByVersion.TryGetValue(minecraftVersion, out downloader)) {
+				Logger.Information("A download for server version {Version} is already running, waiting for it to finish...", minecraftVersion);
 				downloader.Register(listener);
 			}
 			else {
-				downloader = new MinecraftServerExecutableDownloader(version, serverExecutableFilePath, listener);
+				downloader = new MinecraftServerExecutableDownloader(fileDownloadInfo, minecraftVersion, serverExecutableFilePath, listener);
 				downloader.Completed += (_, _) => {
 					lock (this) {
-						runningDownloadersByVersion.Remove(version);
+						runningDownloadersByVersion.Remove(minecraftVersion);
 					}
 				};
-				
-				runningDownloadersByVersion[version] = downloader;
+
+				runningDownloadersByVersion[minecraftVersion] = downloader;
 			}
 		}
 

Agent/Phantom.Agent.Minecraft/Server/ServerExecutableInfo.cs

@@ -1,10 +0,0 @@
-using Phantom.Utils.Cryptography;
-using Phantom.Utils.IO;
-
-namespace Phantom.Agent.Minecraft.Server; 
-
-sealed record ServerExecutableInfo(
-	string DownloadUrl,
-	Sha1String Hash,
-	FileSize Size
-);

Agent/Phantom.Agent.Minecraft/Server/ServerStatusProtocol.cs

@@ -0,0 +1,93 @@
+using System.Buffers;
+using System.Buffers.Binary;
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+using Phantom.Common.Logging;
+using Serilog;
+
+namespace Phantom.Agent.Minecraft.Server;
+
+public sealed class ServerStatusProtocol {
+	private readonly ILogger logger;
+
+	public ServerStatusProtocol(string loggerName) {
+		this.logger = PhantomLogger.Create<ServerStatusProtocol>(loggerName);
+	}
+
+	public async Task<int?> GetOnlinePlayerCount(int serverPort, CancellationToken cancellationToken) {
+		try {
+			return await GetOnlinePlayerCountOrThrow(serverPort, cancellationToken);
+		} catch (Exception e) {
+			logger.Error(e, "Caught exception while checking if players are online.");
+			return null;
+		}
+	}
+
+	private async Task<int?> GetOnlinePlayerCountOrThrow(int serverPort, CancellationToken cancellationToken) {
+		using var tcpClient = new TcpClient();
+		await tcpClient.ConnectAsync(IPAddress.Loopback, serverPort, cancellationToken);
+		var tcpStream = tcpClient.GetStream();
+		
+		// https://wiki.vg/Server_List_Ping
+		tcpStream.WriteByte(0xFE);
+		await tcpStream.FlushAsync(cancellationToken);
+
+		short? messageLength = await ReadStreamHeader(tcpStream, cancellationToken);
+		return messageLength == null ? null : await ReadOnlinePlayerCount(tcpStream, messageLength.Value * 2, cancellationToken);
+	}
+
+	private async Task<short?> ReadStreamHeader(NetworkStream tcpStream, CancellationToken cancellationToken) {
+		var headerBuffer = ArrayPool<byte>.Shared.Rent(3);
+		try {
+			await tcpStream.ReadExactlyAsync(headerBuffer, 0, 3, cancellationToken);
+
+			if (headerBuffer[0] != 0xFF) {
+				logger.Error("Unexpected first byte in response from server: {FirstByte}.", headerBuffer[0]);
+				return null;
+			}
+
+			short messageLength = BinaryPrimitives.ReadInt16BigEndian(headerBuffer.AsSpan(1));
+			if (messageLength <= 0) {
+				logger.Error("Unexpected message length in response from server: {MessageLength}.", messageLength);
+				return null;
+			}
+			
+			return messageLength;
+		} finally {
+			ArrayPool<byte>.Shared.Return(headerBuffer);
+		}
+	}
+
+	private async Task<int?> ReadOnlinePlayerCount(NetworkStream tcpStream, int messageLength, CancellationToken cancellationToken) {
+		var messageBuffer = ArrayPool<byte>.Shared.Rent(messageLength);
+		try {
+			await tcpStream.ReadExactlyAsync(messageBuffer, 0, messageLength, cancellationToken);
+
+			// Valid response separator encoded in UTF-16BE is 0x00 0xA7 (§).
+			const byte SeparatorSecondByte = 0xA7;
+			
+			static bool IsValidSeparator(ReadOnlySpan<byte> buffer, int index) {
+				return index > 0 && buffer[index - 1] == 0x00;
+			}
+			
+			int separator2 = Array.LastIndexOf(messageBuffer, SeparatorSecondByte);
+			int separator1 = separator2 == -1 ? -1 : Array.LastIndexOf(messageBuffer, SeparatorSecondByte, separator2 - 1);
+			if (!IsValidSeparator(messageBuffer, separator1) || !IsValidSeparator(messageBuffer, separator2)) {
+				logger.Error("Could not find message separators in response from server.");
+				return null;
+			}
+
+			string onlinePlayerCountStr = Encoding.BigEndianUnicode.GetString(messageBuffer.AsSpan((separator1 + 1)..(separator2 - 1)));
+			if (!int.TryParse(onlinePlayerCountStr, out int onlinePlayerCount)) {
+				logger.Error("Could not parse online player count in response from server: {OnlinePlayerCount}.", onlinePlayerCountStr);
+				return null;
+			}
+			
+			logger.Debug("Detected {OnlinePlayerCount} online player(s).", onlinePlayerCount);
+			return onlinePlayerCount;
+		} finally {
+			ArrayPool<byte>.Shared.Return(messageBuffer);
+		}
+	}
+}

Agent/Phantom.Agent.Rpc/ControllerConnection.cs

@@ -0,0 +1,25 @@
+using Phantom.Common.Logging;
+using Phantom.Common.Messages.Agent;
+using Phantom.Utils.Rpc;
+using Serilog;
+
+namespace Phantom.Agent.Rpc;
+
+public sealed class ControllerConnection {
+	private static readonly ILogger Logger = PhantomLogger.Create(nameof(ControllerConnection));
+
+	private readonly RpcConnectionToServer<IMessageToControllerListener> connection;
+	
+	public ControllerConnection(RpcConnectionToServer<IMessageToControllerListener> connection) {
+		this.connection = connection;
+		Logger.Information("Connection ready.");
+	}
+
+	public Task Send<TMessage>(TMessage message) where TMessage : IMessageToController {
+		return connection.Send(message);
+	}
+
+	public Task<TReply?> Send<TMessage, TReply>(TMessage message, TimeSpan waitForReplyTime, CancellationToken waitForReplyCancellationToken) where TMessage : IMessageToController<TReply> where TReply : class {
+		return connection.Send<TMessage, TReply>(message, waitForReplyTime, waitForReplyCancellationToken);
+	}
+}

Agent/Phantom.Agent.Rpc/KeepAliveLoop.cs

@@ -0,0 +1,42 @@
+using Phantom.Common.Logging;
+using Phantom.Common.Messages.Agent;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Rpc;
+using Serilog;
+
+namespace Phantom.Agent.Rpc;
+
+sealed class KeepAliveLoop {
+	private static readonly ILogger Logger = PhantomLogger.Create<KeepAliveLoop>();
+
+	private static readonly TimeSpan KeepAliveInterval = TimeSpan.FromSeconds(10);
+
+	private readonly RpcConnectionToServer<IMessageToControllerListener> connection;
+	private readonly CancellationTokenSource cancellationTokenSource = new ();
+
+	public KeepAliveLoop(RpcConnectionToServer<IMessageToControllerListener> connection) {
+		this.connection = connection;
+		Task.Run(Run);
+	}
+
+	private async Task Run() {
+		var cancellationToken = cancellationTokenSource.Token;
+
+		Logger.Information("Started keep-alive loop.");
+		try {
+			while (true) {
+				await Task.Delay(KeepAliveInterval, cancellationToken);
+				await connection.Send(new AgentIsAliveMessage());
+			}
+		} catch (OperationCanceledException) {
+			// Ignore.
+		} finally {
+			cancellationTokenSource.Dispose();
+			Logger.Information("Stopped keep-alive loop.");
+		}
+	}
+
+	public void Cancel() {
+		cancellationTokenSource.Cancel();
+	}
+}

Agent/Phantom.Agent.Rpc/Phantom.Agent.Rpc.csproj

@@ -1,17 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk">
   
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   
   <ItemGroup>
-    <PackageReference Include="Serilog" Version="2.12.0" />
-  </ItemGroup>
-  
-  <ItemGroup>
-    <ProjectReference Include="..\..\Common\Phantom.Common.Messages\Phantom.Common.Messages.csproj" />
+    <ProjectReference Include="..\..\Common\Phantom.Common.Messages.Agent\Phantom.Common.Messages.Agent.csproj" />
   </ItemGroup>
 
 </Project>

Agent/Phantom.Agent.Rpc/RpcClientRuntime.cs

@@ -0,0 +1,38 @@
+using NetMQ;
+using NetMQ.Sockets;
+using Phantom.Common.Data.Agent;
+using Phantom.Common.Messages.Agent;
+using Phantom.Common.Messages.Agent.BiDirectional;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Rpc;
+using Phantom.Utils.Rpc.Sockets;
+using Phantom.Utils.Tasks;
+using Serilog;
+
+namespace Phantom.Agent.Rpc;
+
+public sealed class RpcClientRuntime : RpcClientRuntime<IMessageToAgentListener, IMessageToControllerListener, ReplyMessage> {
+	public static Task Launch(RpcClientSocket<IMessageToAgentListener, IMessageToControllerListener, ReplyMessage> socket, AgentInfo agentInfo, IMessageToAgentListener messageListener, SemaphoreSlim disconnectSemaphore, CancellationToken receiveCancellationToken) {
+		return new RpcClientRuntime(socket, messageListener, disconnectSemaphore, receiveCancellationToken).Launch();
+	}
+
+	private RpcClientRuntime(RpcClientSocket<IMessageToAgentListener, IMessageToControllerListener, ReplyMessage> socket, IMessageToAgentListener messageListener, SemaphoreSlim disconnectSemaphore, CancellationToken receiveCancellationToken) : base(socket, messageListener, disconnectSemaphore, receiveCancellationToken) {}
+
+	protected override void RunWithConnection(ClientSocket socket, RpcConnectionToServer<IMessageToControllerListener> connection, ILogger logger, TaskManager taskManager) {
+		var keepAliveLoop = new KeepAliveLoop(connection);
+		try {
+			base.RunWithConnection(socket, connection, logger, taskManager);
+		} finally {
+			keepAliveLoop.Cancel();
+		}
+	}
+
+	protected override async Task Disconnect(ClientSocket socket, ILogger logger) {
+		var unregisterMessageBytes = AgentMessageRegistries.ToController.Write(new UnregisterAgentMessage()).ToArray();
+		try {
+			await socket.SendAsync(unregisterMessageBytes).AsTask().WaitAsync(TimeSpan.FromSeconds(5), CancellationToken.None);
+		} catch (TimeoutException) {
+			logger.Error("Timed out communicating agent shutdown with the controller.");
+		}
+	}
+}

Agent/Phantom.Agent.Rpc/RpcExtensions.cs

@@ -1,19 +0,0 @@
-using NetMQ;
-using NetMQ.Sockets;
-using Phantom.Common.Messages;
-using Phantom.Common.Messages.ToServer;
-
-namespace Phantom.Agent.Rpc; 
-
-public static class RpcExtensions {
-	internal static async Task SendMessage<TMessage>(this ClientSocket socket, TMessage message) where TMessage : IMessageToServer {
-		byte[] bytes = MessageRegistries.ToServer.Write(message).ToArray();
-		if (bytes.Length > 0) {
-			await socket.SendAsync(bytes);
-		}
-	}
-	
-	public static Task SendSimpleReply<TMessage, TReplyEnum>(this ClientSocket socket, TMessage message, TReplyEnum reply) where TMessage : IMessageWithReply where TReplyEnum : Enum {
-		return SendMessage(socket, SimpleReplyMessage.FromEnum(message.SequenceId, reply));
-	}
-}

Agent/Phantom.Agent.Rpc/RpcLauncher.cs

@@ -1,73 +0,0 @@
-using NetMQ;
-using NetMQ.Sockets;
-using Phantom.Common.Data.Agent;
-using Phantom.Common.Messages;
-using Phantom.Common.Messages.ToServer;
-using Phantom.Utils.Rpc;
-using Serilog.Events;
-
-namespace Phantom.Agent.Rpc;
-
-public sealed class RpcLauncher : RpcRuntime<ClientSocket> {
-	public static async Task Launch(RpcConfiguration config, AgentAuthToken authToken, AgentInfo agentInfo, Func<ClientSocket, IMessageToAgentListener> listenerFactory) {
-		var socket = new ClientSocket();
-		var options = socket.Options;
-
-		options.CurveServerCertificate = config.ServerCertificate;
-		options.CurveCertificate = new NetMQCertificate();
-		options.HelloMessage = MessageRegistries.ToServer.Write(new RegisterAgentMessage(authToken, agentInfo)).ToArray();
-		
-		await new RpcLauncher(config, socket, agentInfo.Guid, listenerFactory).Launch();
-	}
-
-	private readonly RpcConfiguration config;
-	private readonly Guid agentGuid;
-	private readonly Func<ClientSocket, IMessageToAgentListener> messageListenerFactory;
-
-	private RpcLauncher(RpcConfiguration config, ClientSocket socket, Guid agentGuid, Func<ClientSocket, IMessageToAgentListener> messageListenerFactory) : base(socket, config.CancellationToken) {
-		this.config = config;
-		this.agentGuid = agentGuid;
-		this.messageListenerFactory = messageListenerFactory;
-	}
-
-	protected override void Connect(ClientSocket socket) {
-		var logger = config.Logger;
-		var url = config.TcpUrl;
-
-		logger.Information("Starting ZeroMQ client and connecting to {Url}...", url);
-		socket.Connect(url);
-		logger.Information("ZeroMQ client ready.");
-	}
-
-	protected override async Task Run(ClientSocket socket, CancellationToken cancellationToken) {
-		var logger = config.Logger;
-		
-		var listener = messageListenerFactory(socket);
-		
-		ServerMessaging.SetCurrentSocket(socket, cancellationToken);
-
-		// TODO optimize msg
-		await foreach (var bytes in socket.ReceiveBytesAsyncEnumerable(cancellationToken)) {
-			if (logger.IsEnabled(LogEventLevel.Verbose)) {
-				if (bytes.Length > 0 && MessageRegistries.ToAgent.TryGetType(bytes, out var type)) {
-					logger.Verbose("Received {MessageType} ({Bytes} B) from server.", type.Name, bytes.Length);
-				}
-				else {
-					logger.Verbose("Received {Bytes} B message from server.", bytes.Length);
-				}
-			}
-
-			if (bytes.Length > 0) {
-				MessageRegistries.ToAgent.Handle(bytes, listener, cancellationToken);
-			}
-		}
-	}
-
-	protected override async Task Disconnect(ClientSocket socket) {
-		var timeoutTask = Task.Delay(TimeSpan.FromSeconds(5));
-		var finishedTask = await Task.WhenAny(socket.SendMessage(new UnregisterAgentMessage(agentGuid)), timeoutTask);
-		if (finishedTask == timeoutTask) {
-			config.Logger.Error("Timed out communicating agent shutdown with the server.");
-		}
-	}
-}

Agent/Phantom.Agent.Rpc/ServerMessaging.cs

@@ -1,55 +0,0 @@
-using NetMQ.Sockets;
-using Phantom.Common.Logging;
-using Phantom.Common.Messages;
-using Phantom.Common.Messages.ToServer;
-using Serilog;
-
-namespace Phantom.Agent.Rpc;
-
-public static class ServerMessaging {
-	private static readonly ILogger Logger = PhantomLogger.Create(typeof(ServerMessaging));
-	
-	private static readonly TimeSpan KeepAliveInterval = TimeSpan.FromSeconds(10);
-
-	private static ClientSocket? CurrentSocket { get; set; }
-	private static readonly object SetCurrentSocketLock = new ();
-
-	internal static void SetCurrentSocket(ClientSocket socket, CancellationToken cancellationToken) {
-		Logger.Information("Server socket ready.");
-		
-		bool isFirstSet = false;
-		lock (SetCurrentSocketLock) {
-			if (CurrentSocket == null) {
-				isFirstSet = true;
-			}
-
-			CurrentSocket = socket;
-		}
-
-		if (isFirstSet) {
-			Task.Factory.StartNew(static o => SendKeepAliveLoop((CancellationToken) o!), cancellationToken, cancellationToken, TaskCreationOptions.LongRunning, TaskScheduler.Default);
-		}
-	}
-
-	public static async Task SendMessage<TMessage>(TMessage message) where TMessage : IMessageToServer {
-		var currentSocket = CurrentSocket ?? throw new InvalidOperationException("Server socket not ready.");
-		await currentSocket.SendMessage(message);
-	}
-
-	private static async Task SendKeepAliveLoop(CancellationToken cancellationToken) {
-		try {
-			while (true) {
-				await Task.Delay(KeepAliveInterval, cancellationToken);
-
-				var currentSocket = CurrentSocket;
-				if (currentSocket != null) {
-					await currentSocket.SendMessage(new AgentIsAliveMessage());
-				}
-			}
-		} catch (OperationCanceledException) {
-			// Ignore.
-		} finally {
-			Logger.Information("Stopped keep-alive loop.");
-		}
-	}
-}

Agent/Phantom.Agent.Services/AgentFolders.cs

@@ -9,6 +9,7 @@ public sealed class AgentFolders {
 
 	public string DataFolderPath { get; }
 	public string InstancesFolderPath { get; }
+	public string BackupsFolderPath { get; }
 
 	public string TemporaryFolderPath { get; }
 	public string ServerExecutableFolderPath { get; }
@@ -18,6 +19,7 @@ public sealed class AgentFolders {
 	public AgentFolders(string dataFolderPath, string temporaryFolderPath, string javaSearchFolderPath) {
 		this.DataFolderPath = Path.GetFullPath(dataFolderPath);
 		this.InstancesFolderPath = Path.Combine(DataFolderPath, "instances");
+		this.BackupsFolderPath = Path.Combine(DataFolderPath, "backups");
 		
 		this.TemporaryFolderPath = Path.GetFullPath(temporaryFolderPath);
 		this.ServerExecutableFolderPath = Path.Combine(TemporaryFolderPath, "servers");
@@ -28,6 +30,7 @@ public sealed class AgentFolders {
 	public bool TryCreate() {
 		return TryCreateFolder(DataFolderPath) &&
 		       TryCreateFolder(InstancesFolderPath) &&
+		       TryCreateFolder(BackupsFolderPath) &&
 		       TryCreateFolder(TemporaryFolderPath) &&
 		       TryCreateFolder(ServerExecutableFolderPath);
 	}

Agent/Phantom.Agent.Services/AgentServiceConfiguration.cs

@@ -0,0 +1,3 @@
+namespace Phantom.Agent.Services;
+
+public readonly record struct AgentServiceConfiguration(int MaxConcurrentCompressionTasks);

Agent/Phantom.Agent.Services/AgentServices.cs

@@ -1,19 +1,30 @@
 using Phantom.Agent.Minecraft.Java;
+using Phantom.Agent.Rpc;
+using Phantom.Agent.Services.Backups;
 using Phantom.Agent.Services.Instances;
 using Phantom.Common.Data.Agent;
+using Phantom.Common.Logging;
+using Phantom.Utils.Tasks;
+using Serilog;
 
 namespace Phantom.Agent.Services;
 
 public sealed class AgentServices {
-	private AgentFolders AgentFolders { get; }
+	private static readonly ILogger Logger = PhantomLogger.Create<AgentServices>();
 	
+	private AgentFolders AgentFolders { get; }
+	private TaskManager TaskManager { get; }
+	private BackupManager BackupManager { get; }
+
 	internal JavaRuntimeRepository JavaRuntimeRepository { get; }
 	internal InstanceSessionManager InstanceSessionManager { get; }
 
-	public AgentServices(AgentInfo agentInfo, AgentFolders agentFolders) {
+	public AgentServices(AgentInfo agentInfo, AgentFolders agentFolders, AgentServiceConfiguration serviceConfiguration, ControllerConnection controllerConnection) {
 		this.AgentFolders = agentFolders;
+		this.TaskManager = new TaskManager(PhantomLogger.Create<TaskManager, AgentServices>());
+		this.BackupManager = new BackupManager(agentFolders, serviceConfiguration.MaxConcurrentCompressionTasks);
 		this.JavaRuntimeRepository = new JavaRuntimeRepository();
-		this.InstanceSessionManager = new InstanceSessionManager(agentInfo, agentFolders, JavaRuntimeRepository);
+		this.InstanceSessionManager = new InstanceSessionManager(controllerConnection, agentInfo, agentFolders, JavaRuntimeRepository, TaskManager, BackupManager);
 	}
 
 	public async Task Initialize() {
@@ -23,6 +34,13 @@ public sealed class AgentServices {
 	}
 
 	public async Task Shutdown() {
-		await InstanceSessionManager.StopAll();
+		Logger.Information("Stopping services...");
+		
+		await InstanceSessionManager.DisposeAsync();
+		await TaskManager.Stop();
+		
+		BackupManager.Dispose();
+		
+		Logger.Information("Services stopped.");
 	}
 }

Agent/Phantom.Agent.Services/Backups/BackupArchiver.cs

@@ -0,0 +1,180 @@
+using System.Collections.Immutable;
+using System.Diagnostics.CodeAnalysis;
+using System.Formats.Tar;
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Common.Data.Backups;
+using Phantom.Common.Logging;
+using Phantom.Utils.IO;
+using Serilog;
+
+namespace Phantom.Agent.Services.Backups;
+
+sealed class BackupArchiver {
+	private readonly string destinationBasePath;
+	private readonly string temporaryBasePath;
+	private readonly ILogger logger;
+	private readonly InstanceProperties instanceProperties;
+	private readonly CancellationToken cancellationToken;
+	
+	public BackupArchiver(string destinationBasePath, string temporaryBasePath, string loggerName, InstanceProperties instanceProperties, CancellationToken cancellationToken) {
+		this.destinationBasePath = destinationBasePath;
+		this.temporaryBasePath = temporaryBasePath;
+		this.logger = PhantomLogger.Create<BackupArchiver>(loggerName);
+		this.instanceProperties = instanceProperties;
+		this.cancellationToken = cancellationToken;
+	}
+
+	private bool IsFolderSkipped(ImmutableList<string> relativePath) {
+		return relativePath is ["cache" or "crash-reports" or "debug" or "libraries" or "logs" or "mods" or "versions"];
+	}
+	
+	[SuppressMessage("ReSharper", "ConvertIfStatementToReturnStatement")]
+	private bool IsFileSkipped(ImmutableList<string> relativePath) {
+		var name = relativePath[^1];
+		
+		if (relativePath.Count == 2 && name == "session.lock") {
+			return true;
+		}
+
+		var extension = Path.GetExtension(name);
+		if (extension is ".jar" or ".zip") {
+			return true;
+		}
+		
+		return false;
+	}
+
+	public async Task<string?> ArchiveWorld(BackupCreationResult.Builder resultBuilder) {
+		string guid = instanceProperties.InstanceGuid.ToString();
+		string currentDateTime = DateTime.Now.ToString("yyyyMMdd-HHmmss");
+		string backupFolderPath = Path.Combine(destinationBasePath, guid);
+		string backupFilePath = Path.Combine(backupFolderPath, currentDateTime + ".tar");
+		
+		if (File.Exists(backupFilePath)) {
+			resultBuilder.Kind = BackupCreationResultKind.BackupFileAlreadyExists;
+			logger.Warning("Skipping backup, file already exists: {File}", backupFilePath);
+			return null;
+		}
+		
+		try {
+			Directories.Create(backupFolderPath, Chmod.URWX_GRX);
+		} catch (Exception e) {
+			resultBuilder.Kind = BackupCreationResultKind.CouldNotCreateBackupFolder;
+			logger.Error(e, "Could not create backup folder: {Folder}", backupFolderPath);
+			return null;
+		}
+
+		string temporaryFolderPath = Path.Combine(temporaryBasePath, guid + "_" + currentDateTime);
+		if (!await CopyWorldAndCreateTarArchive(temporaryFolderPath, backupFilePath, resultBuilder)) {
+			return null;
+		}
+		
+		logger.Debug("Created world backup: {FilePath}", backupFilePath);
+		return backupFilePath;
+	}
+
+	private async Task<bool> CopyWorldAndCreateTarArchive(string temporaryFolderPath, string backupFilePath, BackupCreationResult.Builder resultBuilder) {
+		try {
+			if (!await CopyWorldToTemporaryFolder(temporaryFolderPath)) {
+				resultBuilder.Kind = BackupCreationResultKind.CouldNotCopyWorldToTemporaryFolder;
+				return false;
+			}
+
+			if (!await CreateTarArchive(temporaryFolderPath, backupFilePath)) {
+				resultBuilder.Kind = BackupCreationResultKind.CouldNotCreateWorldArchive;
+				return false;
+			}
+
+			return true;
+		} finally {
+			try {
+				Directory.Delete(temporaryFolderPath, recursive: true);
+			} catch (Exception e) {
+				resultBuilder.Warnings |= BackupCreationWarnings.CouldNotDeleteTemporaryFolder;
+				logger.Error(e, "Could not delete temporary world folder: {Folder}", temporaryFolderPath);
+			}
+		}
+	}
+
+	private async Task<bool> CopyWorldToTemporaryFolder(string temporaryFolderPath) {
+		try {
+			await CopyDirectory(new DirectoryInfo(instanceProperties.InstanceFolder), temporaryFolderPath, ImmutableList<string>.Empty);
+			return true;
+		} catch (Exception e) {
+			logger.Error(e, "Could not copy world to temporary folder.");
+			return false;
+		}
+	}
+
+	private async Task<bool> CreateTarArchive(string sourceFolderPath, string backupFilePath) {
+		try {
+			await TarFile.CreateFromDirectoryAsync(sourceFolderPath, backupFilePath, false, cancellationToken);
+			return true;
+		} catch (Exception e) {
+			logger.Error(e, "Could not create archive.");
+			DeleteBrokenArchiveFile(backupFilePath);
+			return false;
+		}
+	}
+
+	private void DeleteBrokenArchiveFile(string filePath) {
+		if (File.Exists(filePath)) {
+			try {
+				File.Delete(filePath);
+			} catch (Exception e) {
+				logger.Error(e, "Could not delete broken archive: {File}", filePath);
+			}
+		}
+	}
+
+	private async Task CopyDirectory(DirectoryInfo sourceFolder, string destinationFolderPath, ImmutableList<string> relativePath) {
+		cancellationToken.ThrowIfCancellationRequested();
+
+		bool needsToCreateFolder = true;
+		
+		foreach (FileInfo file in sourceFolder.EnumerateFiles()) {
+			var filePath = relativePath.Add(file.Name);
+			if (IsFileSkipped(filePath)) {
+				logger.Debug("Skipping file: {File}", string.Join('/', filePath));
+				continue;
+			}
+
+			if (needsToCreateFolder) {
+				needsToCreateFolder = false;
+				Directories.Create(destinationFolderPath, Chmod.URWX);
+			}
+
+			await CopyFileWithRetries(file, destinationFolderPath);
+		}
+
+		foreach (DirectoryInfo directory in sourceFolder.EnumerateDirectories()) {
+			var folderPath = relativePath.Add(directory.Name);
+			if (IsFolderSkipped(folderPath)) {
+				logger.Debug("Skipping folder: {Folder}", string.Join('/', folderPath));
+				continue;
+			}
+			
+			await CopyDirectory(directory, Path.Join(destinationFolderPath, directory.Name), folderPath);
+		}
+	}
+
+	private async Task CopyFileWithRetries(FileInfo sourceFile, string destinationFolderPath) {
+		var destinationFilePath = Path.Combine(destinationFolderPath, sourceFile.Name);
+		
+		const int TotalAttempts = 10;
+		for (int attempt = 1; attempt <= TotalAttempts; attempt++) {
+			try {
+				sourceFile.CopyTo(destinationFilePath);
+				return;
+			} catch (IOException) {
+				if (attempt == TotalAttempts) {
+					throw;
+				}
+				else {
+					logger.Warning("Failed copying file {File}, retrying...", sourceFile.FullName);
+					await Task.Delay(200, cancellationToken);
+				}
+			}
+		}
+	}
+}

Agent/Phantom.Agent.Services/Backups/BackupCompressor.cs

@@ -0,0 +1,67 @@
+using Phantom.Common.Logging;
+using Phantom.Utils.Processes;
+using Serilog;
+
+namespace Phantom.Agent.Services.Backups;
+
+static class BackupCompressor {
+	private static ILogger Logger { get; } = PhantomLogger.Create(nameof(BackupCompressor));
+	private static ILogger ZstdLogger { get; } = PhantomLogger.Create(nameof(BackupCompressor), "Zstd");
+	
+	private const string Quality = "-10";
+	private const string Memory = "--long=26";
+	private const string Threads = "-T3";
+	
+	public static async Task<string?> Compress(string sourceFilePath, CancellationToken cancellationToken) {
+		if (sourceFilePath.Contains('"')) {
+			Logger.Error("Could not compress backup, archive path contains quotes: {Path}", sourceFilePath);
+			return null;
+		}
+		
+		var destinationFilePath = sourceFilePath + ".zst";
+
+		if (!await TryCompressFile(sourceFilePath, destinationFilePath, cancellationToken)) {
+			try {
+				File.Delete(destinationFilePath);
+			} catch (Exception e) {
+				Logger.Error(e, "Could not delete compresed archive after unsuccessful compression: {Path}", destinationFilePath);
+			}
+
+			return null;
+		}
+
+		return destinationFilePath;
+	}
+
+	private static async Task<bool> TryCompressFile(string sourceFilePath, string destinationFilePath, CancellationToken cancellationToken) {
+		var workingDirectory = Path.GetDirectoryName(sourceFilePath);
+		if (string.IsNullOrEmpty(workingDirectory)) {
+			Logger.Error("Invalid destination path: {Path}", destinationFilePath);
+			return false;
+		}
+
+		var launcher = new ProcessConfigurator {
+			FileName = "zstd",
+			WorkingDirectory = workingDirectory,
+			ArgumentList = {
+				Quality,
+				Memory,
+				Threads,
+				"--rm",
+				"--no-progress",
+				"-o", destinationFilePath,
+				"--", sourceFilePath
+			}
+		};
+
+		static void OnZstdOutput(object? sender, Process.Output output) {
+			if (!string.IsNullOrWhiteSpace(output.Line)) {
+				ZstdLogger.Debug("[Output] {Line}", output.Line);
+			}
+		}
+
+		var process = new OneShotProcess(ZstdLogger, launcher);
+		process.OutputReceived += OnZstdOutput;
+		return await process.Run(cancellationToken);
+	}
+}

Agent/Phantom.Agent.Services/Backups/BackupManager.cs

@@ -0,0 +1,132 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Common.Data.Backups;
+using Phantom.Common.Logging;
+using Serilog;
+
+namespace Phantom.Agent.Services.Backups;
+
+sealed class BackupManager : IDisposable {
+	private readonly string destinationBasePath;
+	private readonly string temporaryBasePath;
+	private readonly SemaphoreSlim compressionSemaphore;
+
+	public BackupManager(AgentFolders agentFolders, int maxConcurrentCompressionTasks) {
+		this.destinationBasePath = agentFolders.BackupsFolderPath;
+		this.temporaryBasePath = Path.Combine(agentFolders.TemporaryFolderPath, "backups");
+		this.compressionSemaphore = new SemaphoreSlim(maxConcurrentCompressionTasks, maxConcurrentCompressionTasks);
+	}
+
+	public Task<BackupCreationResult> CreateBackup(string loggerName, InstanceProcess process, CancellationToken cancellationToken) {
+		return new BackupCreator(this, loggerName, process, cancellationToken).CreateBackup();
+	}
+
+	public void Dispose() {
+		compressionSemaphore.Dispose();
+	}
+
+	private sealed class BackupCreator {
+		private readonly BackupManager manager;
+		private readonly string loggerName;
+		private readonly ILogger logger;
+		private readonly InstanceProcess process;
+		private readonly CancellationToken cancellationToken;
+
+		public BackupCreator(BackupManager manager, string loggerName, InstanceProcess process, CancellationToken cancellationToken) {
+			this.manager = manager;
+			this.loggerName = loggerName;
+			this.logger = PhantomLogger.Create<BackupManager>(loggerName);
+			this.process = process;
+			this.cancellationToken = cancellationToken;
+		}
+
+		public async Task<BackupCreationResult> CreateBackup() {
+			logger.Information("Backup started.");
+			
+			var resultBuilder = new BackupCreationResult.Builder();
+			string? backupFilePath;
+			
+			using (var dispatcher = new BackupServerCommandDispatcher(logger, process, cancellationToken)) {
+				backupFilePath = await CreateWorldArchive(dispatcher, resultBuilder);
+			}
+			
+			if (backupFilePath != null) {
+				await CompressWorldArchive(backupFilePath, resultBuilder);
+			}
+			
+			var result = resultBuilder.Build();
+			LogBackupResult(result);
+			return result;
+		}
+
+		private async Task<string?> CreateWorldArchive(BackupServerCommandDispatcher dispatcher, BackupCreationResult.Builder resultBuilder) {
+			try {
+				await dispatcher.DisableAutomaticSaving();
+				await dispatcher.SaveAllChunks();
+				return await new BackupArchiver(manager.destinationBasePath, manager.temporaryBasePath, loggerName, process.InstanceProperties, cancellationToken).ArchiveWorld(resultBuilder);
+			} catch (OperationCanceledException) {
+				resultBuilder.Kind = BackupCreationResultKind.BackupCancelled;
+				logger.Warning("Backup creation was cancelled.");
+				return null;
+			} catch (Exception e) {
+				resultBuilder.Kind = BackupCreationResultKind.UnknownError;
+				logger.Error(e, "Caught exception while creating an instance backup.");
+				return null;
+			} finally {
+				try {
+					await dispatcher.EnableAutomaticSaving();
+				} catch (OperationCanceledException) {
+					// Ignore.
+				} catch (Exception e) {
+					resultBuilder.Warnings |= BackupCreationWarnings.CouldNotRestoreAutomaticSaving;
+					logger.Error(e, "Caught exception while enabling automatic saving after creating an instance backup.");
+				}
+			}
+		}
+		
+		private async Task CompressWorldArchive(string filePath, BackupCreationResult.Builder resultBuilder) {
+			if (!await manager.compressionSemaphore.WaitAsync(TimeSpan.FromSeconds(1), cancellationToken)) {
+				logger.Information("Too many compression tasks running, waiting for one of them to complete...");
+				await manager.compressionSemaphore.WaitAsync(cancellationToken);
+			}
+
+			logger.Information("Compressing backup...");
+			try {
+				var compressedFilePath = await BackupCompressor.Compress(filePath, cancellationToken);
+				if (compressedFilePath == null) {
+					resultBuilder.Warnings |= BackupCreationWarnings.CouldNotCompressWorldArchive;
+				}
+			} finally {
+				manager.compressionSemaphore.Release();
+			}
+		}
+
+		private void LogBackupResult(BackupCreationResult result) {
+			if (result.Kind != BackupCreationResultKind.Success) {
+				logger.Warning("Backup failed: {Reason}", DescribeResult(result.Kind));
+				return;
+			}
+			
+			var warningCount = result.Warnings.Count();
+			if (warningCount > 0) {
+				logger.Warning("Backup finished with {Warnings} warning(s).", warningCount);
+			}
+			else {
+				logger.Information("Backup finished successfully.");
+			}
+		}
+
+		private static string DescribeResult(BackupCreationResultKind kind) {
+			return kind switch {
+				BackupCreationResultKind.Success                            => "Backup created successfully.",
+				BackupCreationResultKind.InstanceNotRunning                 => "Instance is not running.",
+				BackupCreationResultKind.BackupCancelled                    => "Backup cancelled.",
+				BackupCreationResultKind.BackupAlreadyRunning               => "A backup is already being created.",
+				BackupCreationResultKind.BackupFileAlreadyExists            => "Backup with the same name already exists.",
+				BackupCreationResultKind.CouldNotCreateBackupFolder         => "Could not create backup folder.",
+				BackupCreationResultKind.CouldNotCopyWorldToTemporaryFolder => "Could not copy world to temporary folder.",
+				BackupCreationResultKind.CouldNotCreateWorldArchive         => "Could not create world archive.",
+				_                                                           => "Unknown error."
+			};
+		}
+	}
+}

Agent/Phantom.Agent.Services/Backups/BackupScheduler.cs

@@ -0,0 +1,116 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Server;
+using Phantom.Agent.Services.Instances;
+using Phantom.Agent.Services.Instances.Procedures;
+using Phantom.Common.Data.Backups;
+using Phantom.Common.Logging;
+using Phantom.Utils.Tasks;
+using Phantom.Utils.Threading;
+
+namespace Phantom.Agent.Services.Backups;
+
+sealed class BackupScheduler : CancellableBackgroundTask {
+	// TODO make configurable
+	private static readonly TimeSpan InitialDelay = TimeSpan.FromMinutes(2);
+	private static readonly TimeSpan BackupInterval = TimeSpan.FromMinutes(30);
+	private static readonly TimeSpan BackupFailureRetryDelay = TimeSpan.FromMinutes(5);
+
+	private readonly BackupManager backupManager;
+	private readonly InstanceProcess process;
+	private readonly IInstanceContext context;
+	private readonly SemaphoreSlim backupSemaphore = new (1, 1);
+	private readonly int serverPort;
+	private readonly ServerStatusProtocol serverStatusProtocol;
+	private readonly ManualResetEventSlim serverOutputWhileWaitingForOnlinePlayers = new ();
+	
+	public event EventHandler<BackupCreationResult>? BackupCompleted;
+
+	public BackupScheduler(TaskManager taskManager, BackupManager backupManager, InstanceProcess process, IInstanceContext context, int serverPort) : base(PhantomLogger.Create<BackupScheduler>(context.ShortName), taskManager, "Backup scheduler for " + context.ShortName) {
+		this.backupManager = backupManager;
+		this.process = process;
+		this.context = context;
+		this.serverPort = serverPort;
+		this.serverStatusProtocol = new ServerStatusProtocol(context.ShortName);
+		Start();
+	}
+
+	protected override async Task RunTask() {
+		await Task.Delay(InitialDelay, CancellationToken);
+		Logger.Information("Starting a new backup after server launched.");
+			
+		while (!CancellationToken.IsCancellationRequested) {
+			var result = await CreateBackup();
+			BackupCompleted?.Invoke(this, result);
+			
+			if (result.Kind.ShouldRetry()) {
+				Logger.Warning("Scheduled backup failed, retrying in {Minutes} minutes.", BackupFailureRetryDelay.TotalMinutes);
+				await Task.Delay(BackupFailureRetryDelay, CancellationToken);
+			}
+			else {
+				Logger.Information("Scheduling next backup in {Minutes} minutes.", BackupInterval.TotalMinutes);
+				await Task.Delay(BackupInterval, CancellationToken);
+				await WaitForOnlinePlayers();
+			}
+		}
+	}
+
+	private async Task<BackupCreationResult> CreateBackup() {
+		if (!await backupSemaphore.WaitAsync(TimeSpan.FromSeconds(1))) {
+			return new BackupCreationResult(BackupCreationResultKind.BackupAlreadyRunning);
+		}
+		
+		try {
+			var procedure = new BackupInstanceProcedure(backupManager);
+			context.EnqueueProcedure(procedure);
+			return await procedure.Result;
+		} finally {
+			backupSemaphore.Release();
+		}
+	}
+
+	private async Task WaitForOnlinePlayers() {
+		bool needsToLogOfflinePlayersMessage = true;
+		
+		process.AddOutputListener(ServerOutputListener, maxLinesToReadFromHistory: 0);
+		try {
+			while (!CancellationToken.IsCancellationRequested) {
+				serverOutputWhileWaitingForOnlinePlayers.Reset();
+				
+				var onlinePlayerCount = await serverStatusProtocol.GetOnlinePlayerCount(serverPort, CancellationToken);
+				if (onlinePlayerCount == null) {
+					Logger.Warning("Could not detect whether any players are online, starting a new backup.");
+					break;
+				}
+
+				if (onlinePlayerCount > 0) {
+					Logger.Information("Players are online, starting a new backup.");
+					break;
+				}
+
+				if (needsToLogOfflinePlayersMessage) {
+					needsToLogOfflinePlayersMessage = false;
+					Logger.Information("No players are online, waiting for someone to join before starting a new backup.");
+				}
+
+				await Task.Delay(TimeSpan.FromSeconds(10), CancellationToken);
+				
+				Logger.Debug("Waiting for server output before checking for online players again...");
+				await serverOutputWhileWaitingForOnlinePlayers.WaitHandle.WaitOneAsync(CancellationToken);
+			}
+		} finally {
+			process.RemoveOutputListener(ServerOutputListener);
+		}
+	}
+
+	private void ServerOutputListener(object? sender, string line) {
+		if (!serverOutputWhileWaitingForOnlinePlayers.IsSet) {
+			serverOutputWhileWaitingForOnlinePlayers.Set();
+			Logger.Debug("Detected server output, signalling to check for online players again.");
+		}
+	}
+
+	protected override void Dispose() {
+		backupSemaphore.Dispose();
+		serverOutputWhileWaitingForOnlinePlayers.Dispose();
+	}
+}

Agent/Phantom.Agent.Services/Backups/BackupServerCommandDispatcher.cs

@@ -0,0 +1,80 @@
+using System.Text.RegularExpressions;
+using Phantom.Agent.Minecraft.Command;
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Utils.Tasks;
+using Serilog;
+
+namespace Phantom.Agent.Services.Backups;
+
+sealed partial class BackupServerCommandDispatcher : IDisposable {
+	[GeneratedRegex(@"^\[(?:.*?)\] \[Server thread/INFO\]: (.*?)$", RegexOptions.NonBacktracking)]
+	private static partial Regex ServerThreadInfoRegex();
+
+	private readonly ILogger logger;
+	private readonly InstanceProcess process;
+	private readonly CancellationToken cancellationToken;
+
+	private readonly TaskCompletionSource automaticSavingDisabled = AsyncTasks.CreateCompletionSource();
+	private readonly TaskCompletionSource savedTheGame = AsyncTasks.CreateCompletionSource();
+	private readonly TaskCompletionSource automaticSavingEnabled = AsyncTasks.CreateCompletionSource();
+
+	public BackupServerCommandDispatcher(ILogger logger, InstanceProcess process, CancellationToken cancellationToken) {
+		this.logger = logger;
+		this.process = process;
+		this.cancellationToken = cancellationToken;
+
+		this.process.AddOutputListener(OnOutput, maxLinesToReadFromHistory: 0);
+	}
+
+	void IDisposable.Dispose() {
+		process.RemoveOutputListener(OnOutput);
+	}
+
+	public async Task DisableAutomaticSaving() {
+		await process.SendCommand(MinecraftCommand.SaveOff, cancellationToken);
+		await automaticSavingDisabled.Task.WaitAsync(cancellationToken);
+	}
+
+	public async Task SaveAllChunks() {
+		// TODO Try if not flushing and waiting a few seconds before flushing reduces lag.
+		await process.SendCommand(MinecraftCommand.SaveAll(flush: true), cancellationToken);
+		await savedTheGame.Task.WaitAsync(cancellationToken);
+	}
+
+	public async Task EnableAutomaticSaving() {
+		await process.SendCommand(MinecraftCommand.SaveOn, cancellationToken);
+		await automaticSavingEnabled.Task.WaitAsync(cancellationToken);
+	}
+
+	private void OnOutput(object? sender, string? line) {
+		if (line == null) {
+			return;
+		}
+
+		var match = ServerThreadInfoRegex().Match(line);
+		if (!match.Success) {
+			return;
+		}
+
+		string info = match.Groups[1].Value;
+
+		if (!automaticSavingDisabled.Task.IsCompleted) {
+			if (info == "Automatic saving is now disabled") {
+				logger.Debug("Detected that automatic saving is disabled.");
+				automaticSavingDisabled.SetResult();
+			}
+		}
+		else if (!savedTheGame.Task.IsCompleted) {
+			if (info == "Saved the game") {
+				logger.Debug("Detected that the game is saved.");
+				savedTheGame.SetResult();
+			}
+		}
+		else if (!automaticSavingEnabled.Task.IsCompleted) {
+			if (info == "Automatic saving is now enabled") {
+				logger.Debug("Detected that automatic saving is enabled.");
+				automaticSavingEnabled.SetResult();
+			}
+		}
+	}
+}

Agent/Phantom.Agent.Services/Instances/IInstanceContext.cs

@@ -0,0 +1,25 @@
+using Phantom.Agent.Services.Instances.Procedures;
+using Phantom.Agent.Services.Instances.States;
+using Phantom.Common.Data.Instance;
+using Serilog;
+
+namespace Phantom.Agent.Services.Instances;
+
+interface IInstanceContext {
+	string ShortName { get; }
+	ILogger Logger { get; }
+	
+	InstanceServices Services { get; }
+	IInstanceState CurrentState { get; }
+
+	void SetStatus(IInstanceStatus newStatus);
+	void ReportEvent(IInstanceEvent instanceEvent);
+	void EnqueueProcedure(IInstanceProcedure procedure, bool immediate = false);
+}
+
+static class InstanceContextExtensions {
+	public static void SetLaunchFailedStatusAndReportEvent(this IInstanceContext context, InstanceLaunchFailReason reason) {
+		context.SetStatus(InstanceStatus.Failed(reason));
+		context.ReportEvent(new InstanceLaunchFailedEvent(reason));
+	}
+}

Agent/Phantom.Agent.Services/Instances/Instance.cs

@@ -1,172 +1,187 @@
 using Phantom.Agent.Minecraft.Launcher;
-using Phantom.Agent.Rpc;
+using Phantom.Agent.Services.Instances.Procedures;
 using Phantom.Agent.Services.Instances.States;
 using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Data.Replies;
 using Phantom.Common.Logging;
-using Phantom.Common.Messages.ToServer;
+using Phantom.Common.Messages.Agent.ToController;
 using Serilog;
 
 namespace Phantom.Agent.Services.Instances;
 
-sealed class Instance : IDisposable {
-	private static uint loggerSequenceId = 0;
-
-	private static string GetLoggerName(Guid guid) {
-		var prefix = guid.ToString();
-		return prefix[..prefix.IndexOf('-')] + "/" + Interlocked.Increment(ref loggerSequenceId);
-	}
-
-	public static async Task<Instance> Create(InstanceConfiguration configuration, BaseLauncher launcher, LaunchServices launchServices, PortManager portManager) {
-		var instance = new Instance(configuration, launcher, launchServices, portManager);
-		await instance.ReportLastStatus();
-		return instance;
-	}
-
+sealed class Instance : IAsyncDisposable {
+	private InstanceServices Services { get; }
+	
 	public InstanceConfiguration Configuration { get; private set; }
-	private BaseLauncher Launcher { get; set; }
+	private IServerLauncher Launcher { get; set; }
+	private readonly SemaphoreSlim configurationSemaphore = new (1, 1);
 
 	private readonly string shortName;
 	private readonly ILogger logger;
 
-	private readonly LaunchServices launchServices;
-	private readonly PortManager portManager;
-
-	private InstanceStatus currentStatus;
+	private IInstanceStatus currentStatus;
+	private int statusUpdateCounter;
+	
 	private IInstanceState currentState;
-	private readonly SemaphoreSlim stateTransitioningActionSemaphore = new (1, 1);
+	public bool IsRunning => currentState is not InstanceNotRunningState;
+	
+	public event EventHandler? IsRunningChanged;
+	
+	private readonly InstanceProcedureManager procedureManager;
 
-	private Instance(InstanceConfiguration configuration, BaseLauncher launcher, LaunchServices launchServices, PortManager portManager) {
-		this.shortName = GetLoggerName(configuration.InstanceGuid);
+	public Instance(string shortName, InstanceServices services, InstanceConfiguration configuration, IServerLauncher launcher) {
+		this.shortName = shortName;
 		this.logger = PhantomLogger.Create<Instance>(shortName);
 
+		this.Services = services;
 		this.Configuration = configuration;
 		this.Launcher = launcher;
-
-		this.launchServices = launchServices;
-		this.portManager = portManager;
+		
 		this.currentState = new InstanceNotRunningState();
-		this.currentStatus = InstanceStatus.IsNotRunning;
+		this.currentStatus = InstanceStatus.NotRunning;
+		
+		this.procedureManager = new InstanceProcedureManager(this, new Context(this), services.TaskManager);
 	}
 
-	private async Task ReportLastStatus() {
-		await ServerMessaging.SendMessage(new ReportInstanceStatusMessage(Configuration.InstanceGuid, currentStatus));
+	private void TryUpdateStatus(string taskName, Func<Task> getUpdateTask) {
+		int myStatusUpdateCounter = Interlocked.Increment(ref statusUpdateCounter);
+		
+		Services.TaskManager.Run(taskName, async () => {
+			if (myStatusUpdateCounter == statusUpdateCounter) {
+				await getUpdateTask();
+			}
+		});
+	}
+
+	public void ReportLastStatus() {
+		TryUpdateStatus("Report last status of instance " + shortName, async () => {
+			await Services.ControllerConnection.Send(new ReportInstanceStatusMessage(Configuration.InstanceGuid, currentStatus));
+		});
+	}
+
+	private void ReportAndSetStatus(IInstanceStatus status) {
+		TryUpdateStatus("Report status of instance " + shortName + " as " + status.GetType().Name, async () => {
+			if (status != currentStatus) {
+				currentStatus = status;
+				await Services.ControllerConnection.Send(new ReportInstanceStatusMessage(Configuration.InstanceGuid, status));
+			}
+		});
+	}
+
+	private void ReportEvent(IInstanceEvent instanceEvent) {
+		var message = new ReportInstanceEventMessage(Guid.NewGuid(), DateTime.UtcNow, Configuration.InstanceGuid, instanceEvent);
+		Services.TaskManager.Run("Report event for instance " + shortName, async () => await Services.ControllerConnection.Send(message));
 	}
 	
-	private bool TransitionState(IInstanceState newState) {
+	internal void TransitionState(IInstanceState newState) {
 		if (currentState == newState) {
-			return false;
+			return;
 		}
 
 		if (currentState is IDisposable disposable) {
 			disposable.Dispose();
 		}
 
+		logger.Debug("Transitioning instance state to: {NewState}", newState.GetType().Name);
+		
+		var wasRunning = IsRunning;
 		currentState = newState;
-		return true;
+		currentState.Initialize();
+
+		if (IsRunning != wasRunning) {
+			IsRunningChanged?.Invoke(this, EventArgs.Empty);
+		}
 	}
 
-	public async Task Reconfigure(InstanceConfiguration configuration, BaseLauncher launcher, CancellationToken cancellationToken) {
-		await stateTransitioningActionSemaphore.WaitAsync(cancellationToken);
+	public async Task Reconfigure(InstanceConfiguration configuration, IServerLauncher launcher, CancellationToken cancellationToken) {
+		await configurationSemaphore.WaitAsync(cancellationToken);
 		try {
 			Configuration = configuration;
 			Launcher = launcher;
-			await ReportLastStatus();
 		} finally {
-			stateTransitioningActionSemaphore.Release();
+			configurationSemaphore.Release();
 		}
 	}
 
 	public async Task<LaunchInstanceResult> Launch(CancellationToken cancellationToken) {
-		await stateTransitioningActionSemaphore.WaitAsync(cancellationToken);
-		try {
-			if (TransitionState(currentState.Launch(new InstanceContextImpl(this)))) {
-				return LaunchInstanceResult.LaunchInitiated;
-			}
-
-			return currentState switch {
-				InstanceLaunchingState => LaunchInstanceResult.InstanceAlreadyLaunching,
-				InstanceRunningState   => LaunchInstanceResult.InstanceAlreadyRunning,
-				InstanceStoppingState  => LaunchInstanceResult.InstanceIsStopping,
-				_                      => LaunchInstanceResult.UnknownError
-			};
-		} finally {
-			stateTransitioningActionSemaphore.Release();
+		if (IsRunning) {
+			return LaunchInstanceResult.InstanceAlreadyRunning;
 		}
+
+		if (await procedureManager.GetCurrentProcedure(cancellationToken) is LaunchInstanceProcedure) {
+			return LaunchInstanceResult.InstanceAlreadyLaunching;
+		}
+		
+		LaunchInstanceProcedure procedure;
+		
+		await configurationSemaphore.WaitAsync(cancellationToken);
+		try {
+			procedure = new LaunchInstanceProcedure(Configuration, Launcher);
+		} finally {
+			configurationSemaphore.Release();
+		}
+		
+		ReportAndSetStatus(InstanceStatus.Launching);
+		await procedureManager.Enqueue(procedure);
+		return LaunchInstanceResult.LaunchInitiated;
 	}
 
-	public async Task<StopInstanceResult> Stop() {
-		await stateTransitioningActionSemaphore.WaitAsync();
-		try {
-			if (TransitionState(currentState.Stop())) {
-				return StopInstanceResult.StopInitiated;
-			}
-
-			return currentState switch {
-				InstanceNotRunningState => StopInstanceResult.InstanceAlreadyStopped,
-				InstanceLaunchingState  => StopInstanceResult.StopInitiated,
-				InstanceStoppingState   => StopInstanceResult.InstanceAlreadyStopping,
-				_                       => StopInstanceResult.UnknownError
-			};
-		} finally {
-			stateTransitioningActionSemaphore.Release();
+	public async Task<StopInstanceResult> Stop(MinecraftStopStrategy stopStrategy, CancellationToken cancellationToken) {
+		if (!IsRunning) {
+			return StopInstanceResult.InstanceAlreadyStopped;
 		}
-	}
-
-	public async Task StopAndWait(TimeSpan waitTime) {
-		await Stop();
-
-		using var waitTokenSource = new CancellationTokenSource(waitTime);
-		var waitToken = waitTokenSource.Token;
-
-		while (currentState is not InstanceNotRunningState) {
-			await Task.Delay(TimeSpan.FromMilliseconds(250), waitToken);
+		
+		if (await procedureManager.GetCurrentProcedure(cancellationToken) is StopInstanceProcedure) {
+			return StopInstanceResult.InstanceAlreadyStopping;
 		}
+		
+		ReportAndSetStatus(InstanceStatus.Stopping);
+		await procedureManager.Enqueue(new StopInstanceProcedure(stopStrategy));
+		return StopInstanceResult.StopInitiated;
 	}
 
 	public async Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
 		return await currentState.SendCommand(command, cancellationToken);
 	}
 
-	private sealed class InstanceContextImpl : InstanceContext {
-		private readonly Instance instance;
-		private int statusUpdateCounter;
+	public async ValueTask DisposeAsync() {
+		await procedureManager.DisposeAsync();
 
-		public InstanceContextImpl(Instance instance) : base(instance.Configuration, instance.Launcher) {
-			this.instance = instance;
+		while (currentState is not InstanceNotRunningState) {
+			await Task.Delay(TimeSpan.FromMilliseconds(250), CancellationToken.None);
 		}
 
-		public override LaunchServices LaunchServices => instance.launchServices;
-		public override PortManager PortManager => instance.portManager;
-		public override ILogger Logger => instance.logger;
-		public override string ShortName => instance.shortName;
-
-		public override void ReportStatus(InstanceStatus newStatus) {
-			int myStatusUpdateCounter = Interlocked.Increment(ref statusUpdateCounter);
-			
-			Task.Run(async () => {
-				if (myStatusUpdateCounter == statusUpdateCounter) {
-					instance.currentStatus = newStatus;
-					await ServerMessaging.SendMessage(new ReportInstanceStatusMessage(Configuration.InstanceGuid, newStatus));
-				}
-			});
-		}
-
-		public override void TransitionState(Func<IInstanceState> newState) {
-			instance.stateTransitioningActionSemaphore.Wait();
-			try {
-				instance.TransitionState(newState());
-			} finally {
-				instance.stateTransitioningActionSemaphore.Release();
-			}
-		}
-	}
-
-	public void Dispose() {
 		if (currentState is IDisposable disposable) {
 			disposable.Dispose();
 		}
+		
+		configurationSemaphore.Dispose();
+	}
 
-		stateTransitioningActionSemaphore.Dispose();
+	private sealed class Context : IInstanceContext {
+		public string ShortName => instance.shortName;
+		public ILogger Logger => instance.logger;
+		
+		public InstanceServices Services => instance.Services;
+		public IInstanceState CurrentState => instance.currentState;
+
+		private readonly Instance instance;
+		
+		public Context(Instance instance) {
+			this.instance = instance;
+		}
+
+		public void SetStatus(IInstanceStatus newStatus) {
+			instance.ReportAndSetStatus(newStatus);
+		}
+
+		public void ReportEvent(IInstanceEvent instanceEvent) {
+			instance.ReportEvent(instanceEvent);
+		}
+
+		public void EnqueueProcedure(IInstanceProcedure procedure, bool immediate) {
+			Services.TaskManager.Run("Enqueue procedure for instance " + instance.shortName, () => instance.procedureManager.Enqueue(procedure, immediate));
+		}
 	}
 }

Agent/Phantom.Agent.Services/Instances/InstanceContext.cs

@@ -1,28 +0,0 @@
-using Phantom.Agent.Minecraft.Launcher;
-using Phantom.Agent.Services.Instances.States;
-using Phantom.Common.Data.Instance;
-using Serilog;
-
-namespace Phantom.Agent.Services.Instances;
-
-abstract class InstanceContext {
-	public InstanceConfiguration Configuration { get; }
-	public BaseLauncher Launcher { get; }
-
-	public abstract LaunchServices LaunchServices { get; }
-	public abstract PortManager PortManager { get; }
-	public abstract ILogger Logger { get; }
-	public abstract string ShortName { get; }
-
-	protected InstanceContext(InstanceConfiguration configuration, BaseLauncher launcher) {
-		Configuration = configuration;
-		Launcher = launcher;
-	}
-
-	public abstract void ReportStatus(InstanceStatus newStatus);
-	public abstract void TransitionState(Func<IInstanceState> newState);
-
-	public void TransitionState(IInstanceState newState) {
-		TransitionState(() => newState);
-	}
-}

Agent/Phantom.Agent.Services/Instances/InstanceLogSender.cs

@@ -0,0 +1,84 @@
+using System.Collections.Immutable;
+using System.Threading.Channels;
+using Phantom.Agent.Rpc;
+using Phantom.Common.Logging;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Tasks;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed class InstanceLogSender : CancellableBackgroundTask {
+	private static readonly BoundedChannelOptions BufferOptions = new (capacity: 64) {
+		SingleReader = true,
+		SingleWriter = true,
+		FullMode = BoundedChannelFullMode.DropNewest
+	};
+	
+	private static readonly TimeSpan SendDelay = TimeSpan.FromMilliseconds(200);
+
+	private readonly ControllerConnection controllerConnection;
+	private readonly Guid instanceGuid;
+	private readonly Channel<string> outputChannel;
+	
+	private int droppedLinesSinceLastSend;
+
+	public InstanceLogSender(ControllerConnection controllerConnection, TaskManager taskManager, Guid instanceGuid, string loggerName) : base(PhantomLogger.Create<InstanceLogSender>(loggerName), taskManager, "Instance log sender for " + loggerName) {
+		this.controllerConnection = controllerConnection;
+		this.instanceGuid = instanceGuid;
+		this.outputChannel = Channel.CreateBounded<string>(BufferOptions, OnLineDropped);
+		Start();
+	}
+	
+	protected override async Task RunTask() {
+		var lineReader = outputChannel.Reader;
+		var lineBuilder = ImmutableArray.CreateBuilder<string>();
+		
+		try {
+			while (await lineReader.WaitToReadAsync(CancellationToken)) {
+				await Task.Delay(SendDelay, CancellationToken);
+				await SendOutputToServer(ReadLinesFromChannel(lineReader, lineBuilder));
+			}
+		} catch (OperationCanceledException) {
+			// Ignore.
+		}
+
+		// Flush remaining lines.
+		await SendOutputToServer(ReadLinesFromChannel(lineReader, lineBuilder));
+	}
+
+	private ImmutableArray<string> ReadLinesFromChannel(ChannelReader<string> reader, ImmutableArray<string>.Builder builder) {
+		builder.Clear();
+		
+		while (reader.TryRead(out string? line)) {
+			builder.Add(line);
+		}
+		
+		int droppedLines = Interlocked.Exchange(ref droppedLinesSinceLastSend, 0);
+		if (droppedLines > 0) {
+			builder.Add($"Dropped {droppedLines} {(droppedLines == 1 ? "line" : "lines")} due to buffer overflow.");
+		}
+		
+		return builder.ToImmutable();
+	}
+
+	private async Task SendOutputToServer(ImmutableArray<string> lines) {
+		if (!lines.IsEmpty) {
+			await controllerConnection.Send(new InstanceOutputMessage(instanceGuid, lines));
+		}
+	}
+
+	private void OnLineDropped(string line) {
+		Logger.Warning("Buffer is full, dropped line: {Line}", line);
+		Interlocked.Increment(ref droppedLinesSinceLastSend);
+	}
+
+	public void Enqueue(string line) {
+		outputChannel.Writer.TryWrite(line);
+	}
+
+	protected override void Dispose() {
+		if (!outputChannel.Writer.TryComplete()) {
+			Logger.Error("Could not mark channel as completed.");
+		}
+	}
+}

Agent/Phantom.Agent.Services/Instances/InstanceLogSenderThread.cs

@@ -1,84 +0,0 @@
-using System.Collections.Immutable;
-using System.Diagnostics.CodeAnalysis;
-using Phantom.Agent.Rpc;
-using Phantom.Common.Logging;
-using Phantom.Common.Messages.ToServer;
-using Phantom.Utils.Collections;
-using Serilog;
-
-namespace Phantom.Agent.Services.Instances; 
-
-sealed class InstanceLogSenderThread {
-	private readonly Guid instanceGuid;
-	private readonly ILogger logger;
-	private readonly CancellationTokenSource cancellationTokenSource;
-	private readonly CancellationToken cancellationToken;
-	
-	private readonly SemaphoreSlim semaphore = new (1, 1);
-	private readonly RingBuffer<string> buffer = new (1000);
-	
-	public InstanceLogSenderThread(Guid instanceGuid, string name) {
-		this.instanceGuid = instanceGuid;
-		this.logger = PhantomLogger.Create<InstanceLogSenderThread>(name);
-		this.cancellationTokenSource = new CancellationTokenSource();
-		this.cancellationToken = cancellationTokenSource.Token;
-		
-		var thread = new Thread(Run) {
-			IsBackground = true,
-			Name = "Instance Log Sender (" + name + ")"
-		};
-		
-		thread.Start();
-	}
-
-	[SuppressMessage("ReSharper", "LocalVariableHidesMember")]
-	private async void Run() {
-		logger.Verbose("Thread started.");
-		
-		try {
-			while (!cancellationToken.IsCancellationRequested) {
-				await semaphore.WaitAsync(cancellationToken);
-
-				ImmutableArray<string> lines;
-				
-				try {
-					lines = buffer.Count > 0 ? buffer.EnumerateLast(uint.MaxValue).ToImmutableArray() : ImmutableArray<string>.Empty;
-					buffer.Clear();
-				} finally {
-					semaphore.Release();
-				}
-
-				if (lines.Length > 0) {
-					await ServerMessaging.SendMessage(new InstanceOutputMessage(instanceGuid, lines));
-				}
-
-				await Task.Delay(TimeSpan.FromMilliseconds(200), cancellationToken);
-			}
-		} catch (OperationCanceledException) {
-			// Ignore.
-		} catch (Exception e) {
-			logger.Error(e, "Caught exception in thread.");
-		} finally {
-			cancellationTokenSource.Dispose();
-			logger.Verbose("Thread stopped.");
-		}
-	}
-
-	public void Enqueue(string line) {
-		try {
-			semaphore.Wait(cancellationToken);
-		} catch (Exception) {
-			return;
-		}
-
-		try {
-			buffer.Add(line);
-		} finally {
-			semaphore.Release();
-		}
-	}
-
-	public void Cancel() {
-		cancellationTokenSource.Cancel();
-	}
-}

Agent/Phantom.Agent.Services/Instances/InstanceProcedureManager.cs

@@ -0,0 +1,85 @@
+using Phantom.Agent.Services.Instances.Procedures;
+using Phantom.Common.Data.Minecraft;
+using Phantom.Utils.Tasks;
+using Phantom.Utils.Threading;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed class InstanceProcedureManager : IAsyncDisposable {
+	private readonly record struct CurrentProcedure(IInstanceProcedure Procedure, CancellationTokenSource CancellationTokenSource);
+
+	private readonly ThreadSafeStructRef<CurrentProcedure> currentProcedure = new ();
+	private readonly ThreadSafeLinkedList<IInstanceProcedure> procedureQueue = new ();
+	private readonly AutoResetEvent procedureQueueReady = new (false);
+	private readonly ManualResetEventSlim procedureQueueFinished = new (false);
+
+	private readonly Instance instance;
+	private readonly IInstanceContext context;
+	private readonly CancellationTokenSource shutdownCancellationTokenSource = new ();
+
+	public InstanceProcedureManager(Instance instance, IInstanceContext context, TaskManager taskManager) {
+		this.instance = instance;
+		this.context = context;
+		taskManager.Run("Procedure manager for instance " + context.ShortName, Run);
+	}
+
+	public async Task Enqueue(IInstanceProcedure procedure, bool immediate = false) {
+		await procedureQueue.Add(procedure, toFront: immediate, shutdownCancellationTokenSource.Token);
+		procedureQueueReady.Set();
+	}
+
+	public async Task<IInstanceProcedure?> GetCurrentProcedure(CancellationToken cancellationToken) {
+		return (await currentProcedure.Get(cancellationToken))?.Procedure;
+	}
+
+	private async Task Run() {
+		try {
+			var shutdownCancellationToken = shutdownCancellationTokenSource.Token;
+			while (true) {
+				await procedureQueueReady.WaitOneAsync(shutdownCancellationToken);
+				while (await procedureQueue.TryTakeFromFront(shutdownCancellationToken) is {} nextProcedure) {
+					using var procedureCancellationTokenSource = new CancellationTokenSource();
+					await currentProcedure.Set(new CurrentProcedure(nextProcedure, procedureCancellationTokenSource), shutdownCancellationToken);
+					await RunProcedure(nextProcedure, procedureCancellationTokenSource.Token);
+					await currentProcedure.Set(null, shutdownCancellationToken);
+				}
+			}
+		} catch (OperationCanceledException) {
+			// Ignore.
+		}
+
+		await RunProcedure(new StopInstanceProcedure(MinecraftStopStrategy.Instant), CancellationToken.None);
+		procedureQueueFinished.Set();
+	}
+
+	private async Task RunProcedure(IInstanceProcedure procedure, CancellationToken cancellationToken) {
+		var procedureName = procedure.GetType().Name;
+
+		context.Logger.Debug("Started procedure: {Procedure}", procedureName);
+		try {
+			var newState = await procedure.Run(context, cancellationToken);
+			context.Logger.Debug("Finished procedure: {Procedure}", procedureName);
+
+			if (newState != null) {
+				instance.TransitionState(newState);
+			}
+		} catch (OperationCanceledException) {
+			context.Logger.Debug("Cancelled procedure: {Procedure}", procedureName);
+		} catch (Exception e) {
+			context.Logger.Error(e, "Caught exception while running procedure: {Procedure}", procedureName);
+		}
+	}
+
+	public async ValueTask DisposeAsync() {
+		shutdownCancellationTokenSource.Cancel();
+
+		(await currentProcedure.Get(CancellationToken.None))?.CancellationTokenSource.Cancel();
+		await procedureQueueFinished.WaitHandle.WaitOneAsync();
+
+		currentProcedure.Dispose();
+		procedureQueue.Dispose();
+		procedureQueueReady.Dispose();
+		procedureQueueFinished.Dispose();
+		shutdownCancellationTokenSource.Dispose();
+	}
+}

Agent/Phantom.Agent.Services/Instances/InstanceServices.cs

@@ -0,0 +1,8 @@
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Rpc;
+using Phantom.Agent.Services.Backups;
+using Phantom.Utils.Tasks;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed record InstanceServices(ControllerConnection ControllerConnection, TaskManager TaskManager, PortManager PortManager, BackupManager BackupManager, LaunchServices LaunchServices);

Agent/Phantom.Agent.Services/Instances/InstanceSessionManager.cs

@@ -1,59 +1,85 @@
-using Phantom.Agent.Minecraft.Instance;
+using System.Collections.Immutable;
+using System.Diagnostics.CodeAnalysis;
+using Phantom.Agent.Minecraft.Instance;
 using Phantom.Agent.Minecraft.Java;
 using Phantom.Agent.Minecraft.Launcher;
 using Phantom.Agent.Minecraft.Launcher.Types;
 using Phantom.Agent.Minecraft.Properties;
 using Phantom.Agent.Minecraft.Server;
+using Phantom.Agent.Rpc;
+using Phantom.Agent.Services.Backups;
 using Phantom.Common.Data;
 using Phantom.Common.Data.Agent;
 using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Data.Replies;
 using Phantom.Common.Logging;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.IO;
+using Phantom.Utils.Tasks;
 using Serilog;
 
 namespace Phantom.Agent.Services.Instances;
 
-sealed class InstanceSessionManager : IDisposable {
+sealed class InstanceSessionManager : IAsyncDisposable {
 	private static readonly ILogger Logger = PhantomLogger.Create<InstanceSessionManager>();
-	
+
+	private readonly ControllerConnection controllerConnection;
 	private readonly AgentInfo agentInfo;
 	private readonly string basePath;
 
-	private readonly LaunchServices launchServices;
-	private readonly PortManager portManager;
+	private readonly InstanceServices instanceServices;
 	private readonly Dictionary<Guid, Instance> instances = new ();
 
 	private readonly CancellationTokenSource shutdownCancellationTokenSource = new ();
 	private readonly CancellationToken shutdownCancellationToken;
 	private readonly SemaphoreSlim semaphore = new (1, 1);
 
-	public InstanceSessionManager(AgentInfo agentInfo, AgentFolders agentFolders, JavaRuntimeRepository javaRuntimeRepository) {
+	private uint instanceLoggerSequenceId = 0;
+
+	public InstanceSessionManager(ControllerConnection controllerConnection, AgentInfo agentInfo, AgentFolders agentFolders, JavaRuntimeRepository javaRuntimeRepository, TaskManager taskManager, BackupManager backupManager) {
+		this.controllerConnection = controllerConnection;
 		this.agentInfo = agentInfo;
 		this.basePath = agentFolders.InstancesFolderPath;
-		this.launchServices = new LaunchServices(new MinecraftServerExecutables(agentFolders.ServerExecutableFolderPath), javaRuntimeRepository);
-		this.portManager = new PortManager(agentInfo.AllowedServerPorts, agentInfo.AllowedRconPorts);
 		this.shutdownCancellationToken = shutdownCancellationTokenSource.Token;
+
+		var minecraftServerExecutables = new MinecraftServerExecutables(agentFolders.ServerExecutableFolderPath);
+		var launchServices = new LaunchServices(minecraftServerExecutables, javaRuntimeRepository);
+		var portManager = new PortManager(agentInfo.AllowedServerPorts, agentInfo.AllowedRconPorts);
+
+		this.instanceServices = new InstanceServices(controllerConnection, taskManager, portManager, backupManager, launchServices);
 	}
 
-	public async Task<ConfigureInstanceResult> Configure(InstanceConfiguration configuration) {
+	private async Task<InstanceActionResult<T>> AcquireSemaphoreAndRun<T>(Func<Task<InstanceActionResult<T>>> func) {
 		try {
 			await semaphore.WaitAsync(shutdownCancellationToken);
+			try {
+				return await func();
+			} finally {
+				semaphore.Release();
+			}
 		} catch (OperationCanceledException) {
-			return ConfigureInstanceResult.AgentShuttingDown;
+			return InstanceActionResult.General<T>(InstanceActionGeneralResult.AgentShuttingDown);
 		}
+	}
 
-		var instanceGuid = configuration.InstanceGuid;
-
-		try {
-			var otherInstances = instances.Values.Where(inst => inst.Configuration.InstanceGuid != instanceGuid).ToArray();
-			if (otherInstances.Length + 1 > agentInfo.MaxInstances) {
-				return ConfigureInstanceResult.InstanceLimitExceeded;
+	[SuppressMessage("ReSharper", "ConvertIfStatementToReturnStatement")]
+	private Task<InstanceActionResult<T>> AcquireSemaphoreAndRunWithInstance<T>(Guid instanceGuid, Func<Instance, Task<T>> func) {
+		return AcquireSemaphoreAndRun(async () => {
+			if (instances.TryGetValue(instanceGuid, out var instance)) {
+				return InstanceActionResult.Concrete(await func(instance));
 			}
-
-			var availableMemory = agentInfo.MaxMemory - otherInstances.Aggregate(RamAllocationUnits.Zero, static (total, instance) => total + instance.Configuration.MemoryAllocation);
-			if (availableMemory < configuration.MemoryAllocation) {
-				return ConfigureInstanceResult.MemoryLimitExceeded;
+			else {
+				return InstanceActionResult.General<T>(InstanceActionGeneralResult.InstanceDoesNotExist);
 			}
+		});
+	}
+
+	public async Task<InstanceActionResult<ConfigureInstanceResult>> Configure(InstanceConfiguration configuration, InstanceLaunchProperties launchProperties, bool launchNow, bool alwaysReportStatus) {
+		return await AcquireSemaphoreAndRun(async () => {
+			var instanceGuid = configuration.InstanceGuid;
+			var instanceFolder = Path.Combine(basePath, instanceGuid.ToString());
+			Directories.Create(instanceFolder, Chmod.URWX_GRX);
 
 			var heapMegabytes = configuration.MemoryAllocation.InMegabytes;
 			var jvmProperties = new JvmProperties(
@@ -61,111 +87,111 @@ sealed class InstanceSessionManager : IDisposable {
 				MaximumHeapMegabytes: heapMegabytes
 			);
 
-			var instanceFolder = Path.Combine(basePath, instanceGuid.ToString());
-			Directory.CreateDirectory(instanceFolder);
-
 			var properties = new InstanceProperties(
+				instanceGuid,
 				configuration.JavaRuntimeGuid,
 				jvmProperties,
+				configuration.JvmArguments,
 				instanceFolder,
 				configuration.MinecraftVersion,
-				new ServerProperties(configuration.ServerPort, configuration.RconPort)
+				new ServerProperties(configuration.ServerPort, configuration.RconPort),
+				launchProperties
 			);
 
-			BaseLauncher launcher = new VanillaLauncher(properties);
+			IServerLauncher launcher = configuration.MinecraftServerKind switch {
+				MinecraftServerKind.Vanilla => new VanillaLauncher(properties),
+				MinecraftServerKind.Fabric  => new FabricLauncher(properties),
+				_                           => InvalidLauncher.Instance
+			};
 
 			if (instances.TryGetValue(instanceGuid, out var instance)) {
 				await instance.Reconfigure(configuration, launcher, shutdownCancellationToken);
 				Logger.Information("Reconfigured instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, configuration.InstanceGuid);
+
+				if (alwaysReportStatus) {
+					instance.ReportLastStatus();
+				}
 			}
 			else {
-				instances[instanceGuid] = instance = await Instance.Create(configuration, launcher, launchServices, portManager);
+				instances[instanceGuid] = instance = new Instance(GetInstanceLoggerName(instanceGuid), instanceServices, configuration, launcher);
 				Logger.Information("Created instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, configuration.InstanceGuid);
+
+				instance.ReportLastStatus();
+				instance.IsRunningChanged += OnInstanceIsRunningChanged;
 			}
 
-			if (configuration.LaunchAutomatically) {
-				await instance.Launch(shutdownCancellationToken);
+			if (launchNow) {
+				await LaunchInternal(instance);
 			}
 
-			return ConfigureInstanceResult.Success;
-		} finally {
-			semaphore.Release();
-		}
+			return InstanceActionResult.Concrete(ConfigureInstanceResult.Success);
+		});
 	}
 
-	public async Task<LaunchInstanceResult> Launch(Guid instanceGuid) {
+	private string GetInstanceLoggerName(Guid guid) {
+		var prefix = guid.ToString();
+		return prefix[..prefix.IndexOf('-')] + "/" + Interlocked.Increment(ref instanceLoggerSequenceId);
+	}
+
+	private ImmutableArray<Instance> GetRunningInstancesInternal() {
+		return instances.Values.Where(static instance => instance.IsRunning).ToImmutableArray();
+	}
+
+	private void OnInstanceIsRunningChanged(object? sender, EventArgs e) {
+		instanceServices.TaskManager.Run("Handle instance running state changed event", RefreshAgentStatus);
+	}
+
+	public async Task RefreshAgentStatus() {
 		try {
 			await semaphore.WaitAsync(shutdownCancellationToken);
+			try {
+				var runningInstances = GetRunningInstancesInternal();
+				var runningInstanceCount = runningInstances.Length;
+				var runningInstanceMemory = runningInstances.Aggregate(RamAllocationUnits.Zero, static (total, instance) => total + instance.Configuration.MemoryAllocation);
+				await controllerConnection.Send(new ReportAgentStatusMessage(runningInstanceCount, runningInstanceMemory));
+			} finally {
+				semaphore.Release();
+			}
 		} catch (OperationCanceledException) {
-			return LaunchInstanceResult.AgentShuttingDown;
-		}
-
-		try {
-			if (!instances.TryGetValue(instanceGuid, out var instance)) {
-				return LaunchInstanceResult.InstanceDoesNotExist;
-			}
-			else {
-				return await instance.Launch(shutdownCancellationToken);
-			}
-		} finally {
-			semaphore.Release();
+			// ignore
 		}
 	}
 
-	public async Task<StopInstanceResult> Stop(Guid instanceGuid) {
-		try {
-			await semaphore.WaitAsync(shutdownCancellationToken);
-		} catch (OperationCanceledException) {
-			return StopInstanceResult.AgentShuttingDown;
-		}
-
-		try {
-			if (!instances.TryGetValue(instanceGuid, out var instance)) {
-				return StopInstanceResult.InstanceDoesNotExist;
-			}
-			else {
-				return await instance.Stop();
-			}
-		} finally {
-			semaphore.Release();
-		}
+	public Task<InstanceActionResult<LaunchInstanceResult>> Launch(Guid instanceGuid) {
+		return AcquireSemaphoreAndRunWithInstance(instanceGuid, LaunchInternal);
 	}
 
-	public async Task<SendCommandToInstanceResult> SendCommand(Guid instanceGuid, string command) {
-		try {
-			await semaphore.WaitAsync(shutdownCancellationToken);
-		} catch (OperationCanceledException) {
-			return SendCommandToInstanceResult.AgentShuttingDown;
+	private async Task<LaunchInstanceResult> LaunchInternal(Instance instance) {
+		var runningInstances = GetRunningInstancesInternal();
+		if (runningInstances.Length + 1 > agentInfo.MaxInstances) {
+			return LaunchInstanceResult.InstanceLimitExceeded;
 		}
 
-		try {
-			if (!instances.TryGetValue(instanceGuid, out var instance)) {
-				return SendCommandToInstanceResult.InstanceDoesNotExist;
-			}
-
-			if (!await instance.SendCommand(command, shutdownCancellationToken)) {
-				return SendCommandToInstanceResult.UnknownError;
-			}
-
-			return SendCommandToInstanceResult.Success;
-		} finally {
-			semaphore.Release();
+		var availableMemory = agentInfo.MaxMemory - runningInstances.Aggregate(RamAllocationUnits.Zero, static (total, instance) => total + instance.Configuration.MemoryAllocation);
+		if (availableMemory < instance.Configuration.MemoryAllocation) {
+			return LaunchInstanceResult.MemoryLimitExceeded;
 		}
+
+		return await instance.Launch(shutdownCancellationToken);
 	}
 
-	public async Task StopAll() {
+	public Task<InstanceActionResult<StopInstanceResult>> Stop(Guid instanceGuid, MinecraftStopStrategy stopStrategy) {
+		return AcquireSemaphoreAndRunWithInstance(instanceGuid, instance => instance.Stop(stopStrategy, shutdownCancellationToken));
+	}
+
+	public Task<InstanceActionResult<SendCommandToInstanceResult>> SendCommand(Guid instanceGuid, string command) {
+		return AcquireSemaphoreAndRunWithInstance(instanceGuid, async instance => await instance.SendCommand(command, shutdownCancellationToken) ? SendCommandToInstanceResult.Success : SendCommandToInstanceResult.UnknownError);
+	}
+
+	public async ValueTask DisposeAsync() {
+		Logger.Information("Stopping all instances...");
+		
 		shutdownCancellationTokenSource.Cancel();
 
 		await semaphore.WaitAsync(CancellationToken.None);
-		try {
-			await Task.WhenAll(instances.Values.Select(static instance => instance.StopAndWait(TimeSpan.FromSeconds(30))));
-			instances.Clear();
-		} finally {
-			semaphore.Release();
-		}
-	}
-
-	public void Dispose() {
+		await Task.WhenAll(instances.Values.Select(static instance => instance.DisposeAsync().AsTask()));
+		instances.Clear();
+		
 		shutdownCancellationTokenSource.Dispose();
 		semaphore.Dispose();
 	}

Agent/Phantom.Agent.Services/Instances/PortManager.cs

@@ -14,17 +14,28 @@ sealed class PortManager {
 	}
 
 	public Result Reserve(InstanceConfiguration configuration) {
+		var serverPort = configuration.ServerPort;
+		var rconPort = configuration.RconPort;
+		
+		if (!allowedServerPorts.Contains(serverPort)) {
+			return Result.ServerPortNotAllowed;
+		}
+
+		if (!allowedRconPorts.Contains(rconPort)) {
+			return Result.RconPortNotAllowed;
+		}
+		
 		lock (usedPorts) {
-			if (usedPorts.Contains(configuration.ServerPort)) {
+			if (usedPorts.Contains(serverPort)) {
 				return Result.ServerPortAlreadyInUse;
 			}
 
-			if (usedPorts.Contains(configuration.RconPort)) {
+			if (usedPorts.Contains(rconPort)) {
 				return Result.RconPortAlreadyInUse;
 			}
 
-			usedPorts.Add(configuration.ServerPort);
-			usedPorts.Add(configuration.RconPort);
+			usedPorts.Add(serverPort);
+			usedPorts.Add(rconPort);
 		}
 
 		return Result.Success;
@@ -42,6 +53,6 @@ sealed class PortManager {
 		ServerPortNotAllowed,
 		ServerPortAlreadyInUse,
 		RconPortNotAllowed,
-		RconPortAlreadyInUse,
+		RconPortAlreadyInUse
 	}
 }

Agent/Phantom.Agent.Services/Instances/Procedures/BackupInstanceProcedure.cs

@@ -0,0 +1,29 @@
+using Phantom.Agent.Services.Backups;
+using Phantom.Agent.Services.Instances.States;
+using Phantom.Common.Data.Backups;
+
+namespace Phantom.Agent.Services.Instances.Procedures;
+
+sealed record BackupInstanceProcedure(BackupManager BackupManager) : IInstanceProcedure {
+	private readonly TaskCompletionSource<BackupCreationResult> resultCompletionSource = new ();
+
+	public Task<BackupCreationResult> Result => resultCompletionSource.Task;
+
+	public async Task<IInstanceState?> Run(IInstanceContext context, CancellationToken cancellationToken) {
+		if (context.CurrentState is not InstanceRunningState runningState || runningState.Process.HasEnded) {
+			resultCompletionSource.SetResult(new BackupCreationResult(BackupCreationResultKind.InstanceNotRunning));
+			return null;
+		}
+
+		try {
+			var result = await BackupManager.CreateBackup(context.ShortName, runningState.Process, cancellationToken);
+			resultCompletionSource.SetResult(result);
+		} catch (OperationCanceledException) {
+			resultCompletionSource.SetCanceled(cancellationToken);
+		} catch (Exception e) {
+			resultCompletionSource.SetException(e);
+		}
+
+		return null;
+	}
+}

Agent/Phantom.Agent.Services/Instances/Procedures/IInstanceProcedure.cs

@@ -0,0 +1,7 @@
+using Phantom.Agent.Services.Instances.States;
+
+namespace Phantom.Agent.Services.Instances.Procedures;
+
+interface IInstanceProcedure {
+	Task<IInstanceState?> Run(IInstanceContext context, CancellationToken cancellationToken);
+}

Agent/Phantom.Agent.Services/Instances/Procedures/LaunchInstanceProcedure.cs

@@ -0,0 +1,97 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Minecraft.Server;
+using Phantom.Agent.Services.Instances.States;
+using Phantom.Common.Data.Instance;
+
+namespace Phantom.Agent.Services.Instances.Procedures;
+
+sealed record LaunchInstanceProcedure(InstanceConfiguration Configuration, IServerLauncher Launcher, bool IsRestarting = false) : IInstanceProcedure {
+	public async Task<IInstanceState?> Run(IInstanceContext context, CancellationToken cancellationToken) {
+		if (!IsRestarting && context.CurrentState is InstanceRunningState) {
+			return null;
+		}
+		
+		context.SetStatus(IsRestarting ? InstanceStatus.Restarting : InstanceStatus.Launching);
+
+		InstanceLaunchFailReason? failReason = context.Services.PortManager.Reserve(Configuration) switch {
+			PortManager.Result.ServerPortNotAllowed   => InstanceLaunchFailReason.ServerPortNotAllowed,
+			PortManager.Result.ServerPortAlreadyInUse => InstanceLaunchFailReason.ServerPortAlreadyInUse,
+			PortManager.Result.RconPortNotAllowed     => InstanceLaunchFailReason.RconPortNotAllowed,
+			PortManager.Result.RconPortAlreadyInUse   => InstanceLaunchFailReason.RconPortAlreadyInUse,
+			_                                         => null
+		};
+
+		if (failReason is {} reason) {
+			context.SetLaunchFailedStatusAndReportEvent(reason);
+			return new InstanceNotRunningState();
+		}
+		
+		context.Logger.Information("Session starting...");
+		try {
+			InstanceProcess process = await DoLaunch(context, cancellationToken);
+			return new InstanceRunningState(Configuration, Launcher, process, context);
+		} catch (OperationCanceledException) {
+			context.SetStatus(InstanceStatus.NotRunning);
+		} catch (LaunchFailureException e) {
+			context.Logger.Error(e.LogMessage);
+			context.SetLaunchFailedStatusAndReportEvent(e.Reason);
+		} catch (Exception e) {
+			context.Logger.Error(e, "Caught exception while launching instance.");
+			context.SetLaunchFailedStatusAndReportEvent(InstanceLaunchFailReason.UnknownError);
+		}
+		
+		context.Services.PortManager.Release(Configuration);
+		return new InstanceNotRunningState();
+	}
+
+	private async Task<InstanceProcess> DoLaunch(IInstanceContext context, CancellationToken cancellationToken) {
+		cancellationToken.ThrowIfCancellationRequested();
+
+		byte lastDownloadProgress = byte.MaxValue;
+
+		void OnDownloadProgress(object? sender, DownloadProgressEventArgs args) {
+			byte progress = (byte) Math.Min(args.DownloadedBytes * 100 / args.TotalBytes, 100);
+
+			if (lastDownloadProgress != progress) {
+				lastDownloadProgress = progress;
+				context.SetStatus(InstanceStatus.Downloading(progress));
+			}
+		}
+
+		var launchResult = await Launcher.Launch(context.Logger, context.Services.LaunchServices, OnDownloadProgress, cancellationToken);
+		if (launchResult is LaunchResult.InvalidJavaRuntime) {
+			throw new LaunchFailureException(InstanceLaunchFailReason.JavaRuntimeNotFound, "Session failed to launch, invalid Java runtime.");
+		}
+		else if (launchResult is LaunchResult.CouldNotDownloadMinecraftServer) {
+			throw new LaunchFailureException(InstanceLaunchFailReason.CouldNotDownloadMinecraftServer, "Session failed to launch, could not download Minecraft server.");
+		}
+		else if (launchResult is LaunchResult.CouldNotPrepareMinecraftServerLauncher) {
+			throw new LaunchFailureException(InstanceLaunchFailReason.CouldNotPrepareMinecraftServerLauncher, "Session failed to launch, could not prepare Minecraft server launcher.");
+		}
+		else if (launchResult is LaunchResult.CouldNotConfigureMinecraftServer) {
+			throw new LaunchFailureException(InstanceLaunchFailReason.CouldNotConfigureMinecraftServer, "Session failed to launch, could not configure Minecraft server.");
+		}
+		else if (launchResult is LaunchResult.CouldNotStartMinecraftServer) {
+			throw new LaunchFailureException(InstanceLaunchFailReason.CouldNotStartMinecraftServer, "Session failed to launch, could not start Minecraft server.");
+		}
+
+		if (launchResult is not LaunchResult.Success launchSuccess) {
+			throw new LaunchFailureException(InstanceLaunchFailReason.UnknownError, "Session failed to launch.");
+		}
+
+		context.SetStatus(InstanceStatus.Running);
+		context.ReportEvent(InstanceEvent.LaunchSucceded);
+		return launchSuccess.Process;
+	}
+
+	private sealed class LaunchFailureException : Exception {
+		public InstanceLaunchFailReason Reason { get; }
+		public string LogMessage { get; }
+
+		public LaunchFailureException(InstanceLaunchFailReason reason, string logMessage) {
+			this.Reason = reason;
+			this.LogMessage = logMessage;
+		}
+	}
+}

Agent/Phantom.Agent.Services/Instances/Procedures/SetInstanceToNotRunningStateProcedure.cs

@@ -0,0 +1,17 @@
+using Phantom.Agent.Services.Instances.States;
+using Phantom.Common.Data.Instance;
+
+namespace Phantom.Agent.Services.Instances.Procedures;
+
+sealed record SetInstanceToNotRunningStateProcedure(IInstanceStatus Status) : IInstanceProcedure {
+	public Task<IInstanceState?> Run(IInstanceContext context, CancellationToken cancellationToken) {
+		if (context.CurrentState is InstanceRunningState { Process.HasEnded: true }) {
+			context.SetStatus(Status);
+			context.ReportEvent(InstanceEvent.Stopped);
+			return Task.FromResult<IInstanceState?>(new InstanceNotRunningState());
+		}
+		else {
+			return Task.FromResult<IInstanceState?>(null);
+		}
+	}
+}

Agent/Phantom.Agent.Services/Instances/Procedures/StopInstanceProcedure.cs

@@ -0,0 +1,103 @@
+using System.Diagnostics;
+using Phantom.Agent.Minecraft.Command;
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Services.Instances.States;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Minecraft;
+
+namespace Phantom.Agent.Services.Instances.Procedures;
+
+sealed record StopInstanceProcedure(MinecraftStopStrategy StopStrategy) : IInstanceProcedure {
+	private static readonly ushort[] Stops = { 60, 30, 10, 5, 4, 3, 2, 1, 0 };
+
+	public async Task<IInstanceState?> Run(IInstanceContext context, CancellationToken cancellationToken) {
+		if (context.CurrentState is not InstanceRunningState runningState) {
+			return null;
+		}
+
+		var process = runningState.Process;
+
+		runningState.IsStopping = true;
+		context.SetStatus(InstanceStatus.Stopping);
+
+		var seconds = StopStrategy.Seconds;
+		if (seconds > 0) {
+			try {
+				await CountDownWithAnnouncements(context, process, seconds, cancellationToken);
+			} catch (OperationCanceledException) {
+				runningState.IsStopping = false;
+				return null;
+			}
+		}
+
+		try {
+			// Too late to cancel the stop procedure now.
+			if (!process.HasEnded) {
+				context.Logger.Information("Session stopping now.");
+				await DoStop(context, process);
+			}
+		} finally {
+			context.Logger.Information("Session stopped.");
+			context.SetStatus(InstanceStatus.NotRunning);
+			context.ReportEvent(InstanceEvent.Stopped);
+		}
+
+		return new InstanceNotRunningState();
+	}
+
+	private async Task CountDownWithAnnouncements(IInstanceContext context, InstanceProcess process, ushort seconds, CancellationToken cancellationToken) {
+		context.Logger.Information("Session stopping in {Seconds} seconds.", seconds);
+
+		foreach (var stop in Stops) {
+			// TODO change to event-based cancellation
+			if (process.HasEnded) {
+				return;
+			}
+
+			if (seconds > stop) {
+				await process.SendCommand(GetCountDownAnnouncementCommand(seconds), cancellationToken);
+				await Task.Delay(TimeSpan.FromSeconds(seconds - stop), cancellationToken);
+				seconds = stop;
+			}
+		}
+	}
+
+	private static string GetCountDownAnnouncementCommand(ushort seconds) {
+		return MinecraftCommand.Say("Server shutting down in " + seconds + (seconds == 1 ? " second." : " seconds."));
+	}
+
+	private async Task DoStop(IInstanceContext context, InstanceProcess process) {
+		context.Logger.Information("Sending stop command...");
+		await TrySendStopCommand(context, process);
+
+		context.Logger.Information("Waiting for session to end...");
+		await WaitForSessionToEnd(context, process);
+	}
+
+	private async Task TrySendStopCommand(IInstanceContext context, InstanceProcess process) {
+		using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(5));
+		try {
+			await process.SendCommand(MinecraftCommand.Stop, timeout.Token);
+		} catch (OperationCanceledException) {
+			// Ignore.
+		} catch (ObjectDisposedException e) when (e.ObjectName == typeof(Process).FullName && process.HasEnded) {
+			// Ignore.
+		} catch (Exception e) {
+			context.Logger.Warning(e, "Caught exception while sending stop command.");
+		}
+	}
+
+	private async Task WaitForSessionToEnd(IInstanceContext context, InstanceProcess process) {
+		using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(55));
+		try {
+			await process.WaitForExit(timeout.Token);
+		} catch (OperationCanceledException) {
+			try {
+				context.Logger.Warning("Waiting timed out, killing session...");
+				process.Kill();
+			} catch (Exception e) {
+				context.Logger.Error(e, "Caught exception while killing session.");
+			}
+		}
+	}
+}

Agent/Phantom.Agent.Services/Instances/States/IInstanceState.cs

@@ -1,7 +1,6 @@
-namespace Phantom.Agent.Services.Instances.States; 
+namespace Phantom.Agent.Services.Instances.States;
 
 interface IInstanceState {
-	IInstanceState Launch(InstanceContext context);
-	IInstanceState Stop();
+	void Initialize();
 	Task<bool> SendCommand(string command, CancellationToken cancellationToken);
 }

Agent/Phantom.Agent.Services/Instances/States/InstanceLaunchingState.cs

@@ -1,104 +0,0 @@
-using Phantom.Agent.Minecraft.Instance;
-using Phantom.Agent.Minecraft.Launcher;
-using Phantom.Agent.Minecraft.Server;
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances.States;
-
-sealed class InstanceLaunchingState : IInstanceState, IDisposable {
-	private readonly InstanceContext context;
-	private readonly CancellationTokenSource cancellationTokenSource = new ();
-	private byte lastDownloadProgress = byte.MaxValue;
-
-	public InstanceLaunchingState(InstanceContext context) {
-		this.context = context;
-		this.context.Logger.Information("Session starting...");
-		this.context.ReportStatus(InstanceStatus.IsLaunching);
-		
-		var launchTask = Task.Run(DoLaunch);
-		launchTask.ContinueWith(OnLaunchSuccess, CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, TaskScheduler.Default);
-		launchTask.ContinueWith(OnLaunchFailure, CancellationToken.None, TaskContinuationOptions.NotOnRanToCompletion, TaskScheduler.Default);
-	}
-
-	private async Task<InstanceSession> DoLaunch() {
-		var cancellationToken = cancellationTokenSource.Token;
-		cancellationToken.ThrowIfCancellationRequested();
-		
-		void OnDownloadProgress(object? sender, DownloadProgressEventArgs args) {
-			byte progress = (byte) Math.Min(args.DownloadedBytes * 100 / args.TotalBytes, 100);
-			
-			if (lastDownloadProgress != progress) {
-				lastDownloadProgress = progress;
-				context.ReportStatus(new InstanceStatus.Downloading(progress));
-			}
-		}
-
-		var launchResult = await context.Launcher.Launch(context.LaunchServices, OnDownloadProgress, cancellationToken);
-		if (launchResult is LaunchResult.CouldNotDownloadMinecraftServer) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.CouldNotDownloadMinecraftServer, "Session failed to launch, could not download Minecraft server.");
-		}
-		else if (launchResult is LaunchResult.InvalidJavaRuntime) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.JavaRuntimeNotFound, "Session failed to launch, invalid Java runtime.");
-		}
-
-		if (launchResult is not LaunchResult.Success launchSuccess) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.UnknownError, "Session failed to launch.");
-		}
-
-		context.ReportStatus(InstanceStatus.IsLaunching);
-		return launchSuccess.Session;
-	}
-
-	private void OnLaunchSuccess(Task<InstanceSession> task) {
-		context.TransitionState(() => {
-			if (cancellationTokenSource.IsCancellationRequested) {
-				context.PortManager.Release(context.Configuration);
-				context.ReportStatus(InstanceStatus.IsNotRunning);
-				return new InstanceNotRunningState();
-			}
-			else {
-				return new InstanceRunningState(context, task.Result);
-			}
-		});
-	}
-
-	private void OnLaunchFailure(Task task) {
-		if (task.Exception is { InnerException: LaunchFailureException e }) {
-			context.Logger.Error(e.LogMessage);
-			context.ReportStatus(new InstanceStatus.Failed(e.Reason));
-		}
-		else {
-			context.ReportStatus(new InstanceStatus.Failed(InstanceLaunchFailReason.UnknownError));
-		}
-		
-		context.PortManager.Release(context.Configuration);
-		context.TransitionState(new InstanceNotRunningState());
-	}
-
-	private sealed class LaunchFailureException : Exception {
-		public InstanceLaunchFailReason Reason { get; }
-		public string LogMessage { get; }
-		
-		public LaunchFailureException(InstanceLaunchFailReason reason, string logMessage) {
-			this.Reason = reason;
-			this.LogMessage = logMessage;
-		}
-	}
-
-	public IInstanceState Launch(InstanceContext context) {
-		return this;
-	}
-
-	public IInstanceState Stop() {
-		cancellationTokenSource.Cancel();
-		return this;
-	}
-
-	public Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
-		return Task.FromResult(false);
-	}
-
-	public void Dispose() {
-		cancellationTokenSource.Dispose();
-	}
-}

Agent/Phantom.Agent.Services/Instances/States/InstanceNotRunningState.cs

@@ -1,28 +1,7 @@
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances.States; 
+namespace Phantom.Agent.Services.Instances.States;
 
 sealed class InstanceNotRunningState : IInstanceState {
-	public IInstanceState Launch(InstanceContext context) {
-		InstanceLaunchFailReason? failReason = context.PortManager.Reserve(context.Configuration) switch {
-			PortManager.Result.ServerPortNotAllowed   => InstanceLaunchFailReason.ServerPortNotAllowed,
-			PortManager.Result.ServerPortAlreadyInUse => InstanceLaunchFailReason.ServerPortAlreadyInUse,
-			PortManager.Result.RconPortNotAllowed     => InstanceLaunchFailReason.RconPortNotAllowed,
-			PortManager.Result.RconPortAlreadyInUse   => InstanceLaunchFailReason.RconPortAlreadyInUse,
-			_                                         => null
-		};
-
-		if (failReason != null) {
-			context.ReportStatus(new InstanceStatus.Failed(failReason.Value));
-			return this;
-		}
-		
-		return new InstanceLaunchingState(context);
-	}
-
-	public IInstanceState Stop() {
-		return this;
-	}
+	public void Initialize() {}
 
 	public Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
 		return Task.FromResult(false);

Agent/Phantom.Agent.Services/Instances/States/InstanceRunningState.cs

@@ -1,62 +1,81 @@
 using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Services.Backups;
+using Phantom.Agent.Services.Instances.Procedures;
+using Phantom.Common.Data.Backups;
 using Phantom.Common.Data.Instance;
 
 namespace Phantom.Agent.Services.Instances.States;
 
-sealed class InstanceRunningState : IInstanceState {
-	private readonly InstanceContext context;
-	private readonly InstanceSession session;
-	private readonly InstanceLogSenderThread logSenderThread;
-	private readonly SessionObjects sessionObjects;
+sealed class InstanceRunningState : IInstanceState, IDisposable {
+	public InstanceProcess Process { get; }
 
-	public InstanceRunningState(InstanceContext context, InstanceSession session) {
+	internal bool IsStopping { get; set; }
+
+	private readonly InstanceConfiguration configuration;
+	private readonly IServerLauncher launcher;
+	private readonly IInstanceContext context;
+
+	private readonly InstanceLogSender logSender;
+	private readonly BackupScheduler backupScheduler;
+
+	private bool isDisposed;
+
+	public InstanceRunningState(InstanceConfiguration configuration, IServerLauncher launcher, InstanceProcess process, IInstanceContext context) {
+		this.configuration = configuration;
+		this.launcher = launcher;
 		this.context = context;
-		this.session = session;
-		this.logSenderThread = new InstanceLogSenderThread(context.Configuration.InstanceGuid, context.ShortName);
-		this.sessionObjects = new SessionObjects(context, session, logSenderThread);
+		this.Process = process;
 
-		this.session.AddOutputListener(SessionOutput);
-		this.session.SessionEnded += SessionEnded;
+		this.logSender = new InstanceLogSender(context.Services.ControllerConnection, context.Services.TaskManager, configuration.InstanceGuid, context.ShortName);
 
-		if (session.HasEnded) {
-			if (sessionObjects.Dispose()) {
+		this.backupScheduler = new BackupScheduler(context.Services.TaskManager, context.Services.BackupManager, process, context, configuration.ServerPort);
+		this.backupScheduler.BackupCompleted += OnScheduledBackupCompleted;
+	}
+
+	public void Initialize() {
+		Process.Ended += ProcessEnded;
+
+		if (Process.HasEnded) {
+			if (TryDispose()) {
 				context.Logger.Warning("Session ended immediately after it was started.");
-				context.ReportStatus(new InstanceStatus.Failed(InstanceLaunchFailReason.UnknownError));
-				Task.Run(() => context.TransitionState(new InstanceNotRunningState()));
+				context.EnqueueProcedure(new SetInstanceToNotRunningStateProcedure(InstanceStatus.Failed(InstanceLaunchFailReason.UnknownError)), immediate: true);
 			}
 		}
 		else {
-			context.ReportStatus(InstanceStatus.IsRunning);
 			context.Logger.Information("Session started.");
+			Process.AddOutputListener(SessionOutput);
 		}
 	}
 
-	private void SessionOutput(object? sender, string e) {
-		context.Logger.Verbose("[Server] {Line}", e);
-		logSenderThread.Enqueue(e);
+	private void SessionOutput(object? sender, string line) {
+		context.Logger.Debug("[Server] {Line}", line);
+		logSender.Enqueue(line);
 	}
 
-	private void SessionEnded(object? sender, EventArgs e) {
-		if (sessionObjects.Dispose()) {
-			context.Logger.Information("Session ended.");
-			context.ReportStatus(InstanceStatus.IsNotRunning);
-			context.TransitionState(new InstanceNotRunningState());
+	private void ProcessEnded(object? sender, EventArgs e) {
+		if (!TryDispose()) {
+			return;
+		}
+
+		if (IsStopping) {
+			context.EnqueueProcedure(new SetInstanceToNotRunningStateProcedure(InstanceStatus.NotRunning), immediate: true);
+		}
+		else {
+			context.Logger.Information("Session ended unexpectedly, restarting...");
+			context.ReportEvent(InstanceEvent.Crashed);
+			context.EnqueueProcedure(new LaunchInstanceProcedure(configuration, launcher, IsRestarting: true));
 		}
 	}
 
-	public IInstanceState Launch(InstanceContext context) {
-		return this;
-	}
-
-	public IInstanceState Stop() {
-		session.SessionEnded -= SessionEnded;
-		return new InstanceStoppingState(context, session, sessionObjects);
+	private void OnScheduledBackupCompleted(object? sender, BackupCreationResult e) {
+		context.ReportEvent(new InstanceBackupCompletedEvent(e.Kind, e.Warnings));
 	}
 
 	public async Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
 		try {
 			context.Logger.Information("Sending command: {Command}", command);
-			await session.SendCommand(command, cancellationToken);
+			await Process.SendCommand(command, cancellationToken);
 			return true;
 		} catch (OperationCanceledException) {
 			return false;
@@ -66,31 +85,25 @@ sealed class InstanceRunningState : IInstanceState {
 		}
 	}
 
-	public sealed class SessionObjects {
-		private readonly InstanceContext context;
-		private readonly InstanceSession session;
-		private readonly InstanceLogSenderThread logSenderThread;
-		private bool isDisposed;
-
-		public SessionObjects(InstanceContext context, InstanceSession session, InstanceLogSenderThread logSenderThread) {
-			this.context = context;
-			this.session = session;
-			this.logSenderThread = logSenderThread;
-		}
-
-		public bool Dispose() {
-			lock (this) {
-				if (isDisposed) {
-					return false;
-				}
-
-				isDisposed = true;
+	private bool TryDispose() {
+		lock (this) {
+			if (isDisposed) {
+				return false;
 			}
 
-			logSenderThread.Cancel();
-			session.Dispose();
-			context.PortManager.Release(context.Configuration);
-			return true;
+			isDisposed = true;
 		}
+
+		logSender.Stop();
+		backupScheduler.Stop();
+		
+		Process.Dispose();
+		context.Services.PortManager.Release(configuration);
+		
+		return true;
+	}
+
+	public void Dispose() {
+		TryDispose();
 	}
 }

Agent/Phantom.Agent.Services/Instances/States/InstanceStoppingState.cs

@@ -1,75 +0,0 @@
-using Phantom.Agent.Minecraft.Instance;
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances.States; 
-
-sealed class InstanceStoppingState : IInstanceState, IDisposable {
-	private readonly InstanceContext context;
-	private readonly InstanceSession session;
-	private readonly InstanceRunningState.SessionObjects sessionObjects;
-
-	public InstanceStoppingState(InstanceContext context, InstanceSession session, InstanceRunningState.SessionObjects sessionObjects) {
-		this.sessionObjects = sessionObjects;
-		this.session = session;
-		this.context = context;
-		this.context.Logger.Information("Session stopping.");
-		this.context.ReportStatus(InstanceStatus.IsStopping);
-		
-		Task.Run(DoStop);
-	}
-
-	private async Task DoStop() {
-		try {
-			context.Logger.Information("Sending stop command...");
-			await DoSendStopCommand();
-
-			context.Logger.Information("Waiting for session to end...");
-			await DoWaitForSessionToEnd();
-		} finally {
-			context.Logger.Information("Session stopped.");
-			context.ReportStatus(InstanceStatus.IsNotRunning);
-			context.TransitionState(new InstanceNotRunningState());
-		}
-	}
-
-	private async Task DoSendStopCommand() {
-		using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
-		try {
-			await session.SendCommand("stop", cts.Token);
-		} catch (OperationCanceledException) {
-			// ignore
-		} catch (Exception e) {
-			context.Logger.Warning(e, "Caught exception while sending stop command.");
-		}
-	}
-
-	private async Task DoWaitForSessionToEnd() {
-		using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(55));
-		try {
-			await session.WaitForExit(cts.Token);
-		} catch (OperationCanceledException) {
-			try {
-				context.Logger.Warning("Waiting timed out, killing session...");
-				session.Kill();
-			} catch (Exception e) {
-				context.Logger.Error(e, "Caught exception while killing session.");
-			}
-		}
-	}
-
-	public IInstanceState Launch(InstanceContext context) {
-		return this;
-	}
-
-	public IInstanceState Stop() {
-		return this; // TODO maybe provide a way to kill?
-	}
-
-	public Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
-		return Task.FromResult(false);
-	}
-
-	public void Dispose() {
-		sessionObjects.Dispose();
-	}
-}

Agent/Phantom.Agent.Services/Phantom.Agent.Services.csproj

@@ -1,13 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk">
   
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   
   <ItemGroup>
-    <ProjectReference Include="..\..\Common\Phantom.Common.Messages\Phantom.Common.Messages.csproj" />
+    <ProjectReference Include="..\..\Common\Phantom.Common.Messages.Agent\Phantom.Common.Messages.Agent.csproj" />
     <ProjectReference Include="..\Phantom.Agent.Minecraft\Phantom.Agent.Minecraft.csproj" />
     <ProjectReference Include="..\Phantom.Agent.Rpc\Phantom.Agent.Rpc.csproj" />
   </ItemGroup>

Agent/Phantom.Agent.Services/Rpc/MessageListener.cs

@@ -1,10 +1,12 @@
-using NetMQ.Sockets;
-using Phantom.Agent.Rpc;
+using Phantom.Common.Data.Instance;
 using Phantom.Common.Data.Replies;
 using Phantom.Common.Logging;
-using Phantom.Common.Messages;
-using Phantom.Common.Messages.ToAgent;
-using Phantom.Common.Messages.ToServer;
+using Phantom.Common.Messages.Agent;
+using Phantom.Common.Messages.Agent.BiDirectional;
+using Phantom.Common.Messages.Agent.ToAgent;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Rpc;
+using Phantom.Utils.Rpc.Message;
 using Serilog;
 
 namespace Phantom.Agent.Services.Rpc;
@@ -12,32 +14,39 @@ namespace Phantom.Agent.Services.Rpc;
 public sealed class MessageListener : IMessageToAgentListener {
 	private static ILogger Logger { get; } = PhantomLogger.Create<MessageListener>();
 
-	private readonly ClientSocket socket;
+	private readonly RpcConnectionToServer<IMessageToControllerListener> connection;
 	private readonly AgentServices agent;
 	private readonly CancellationTokenSource shutdownTokenSource;
 
-	public MessageListener(ClientSocket socket, AgentServices agent, CancellationTokenSource shutdownTokenSource) {
-		this.socket = socket;
+	public MessageListener(RpcConnectionToServer<IMessageToControllerListener> connection, AgentServices agent, CancellationTokenSource shutdownTokenSource) {
+		this.connection = connection;
 		this.agent = agent;
 		this.shutdownTokenSource = shutdownTokenSource;
 	}
 
-	public async Task HandleRegisterAgentSuccessResult(RegisterAgentSuccessMessage message) {
+	public async Task<NoReply> HandleRegisterAgentSuccess(RegisterAgentSuccessMessage message) {
 		Logger.Information("Agent authentication successful.");
 
-		foreach (var instanceInfo in message.InitialInstances) {
-			if (await agent.InstanceSessionManager.Configure(instanceInfo) != ConfigureInstanceResult.Success) {
-				Logger.Fatal("Unable to configure instance \"{Name}\" (GUID {Guid}), shutting down.", instanceInfo.InstanceName, instanceInfo.InstanceGuid);
-
-				shutdownTokenSource.Cancel();
-				return;
+		void ShutdownAfterConfigurationFailed(InstanceConfiguration configuration) {
+			Logger.Fatal("Unable to configure instance \"{Name}\" (GUID {Guid}), shutting down.", configuration.InstanceName, configuration.InstanceGuid);
+			shutdownTokenSource.Cancel();
+		}
+		
+		foreach (var configureInstanceMessage in message.InitialInstanceConfigurations) {
+			var result = await HandleConfigureInstance(configureInstanceMessage, alwaysReportStatus: true);
+			if (!result.Is(ConfigureInstanceResult.Success)) {
+				ShutdownAfterConfigurationFailed(configureInstanceMessage.Configuration);
+				return NoReply.Instance;
 			}
 		}
 
-		await ServerMessaging.SendMessage(new AdvertiseJavaRuntimesMessage(agent.JavaRuntimeRepository.All));
+		await connection.Send(new AdvertiseJavaRuntimesMessage(agent.JavaRuntimeRepository.All));
+		await agent.InstanceSessionManager.RefreshAgentStatus();
+		
+		return NoReply.Instance;
 	}
 
-	public Task HandleRegisterAgentFailureResult(RegisterAgentFailureMessage message) {
+	public Task<NoReply> HandleRegisterAgentFailure(RegisterAgentFailureMessage message) {
 		string errorMessage = message.FailureKind switch {
 			RegisterAgentFailure.ConnectionAlreadyHasAnAgent => "This connection already has an associated agent.",
 			RegisterAgentFailure.InvalidToken                => "Invalid token.",
@@ -45,24 +54,35 @@ public sealed class MessageListener : IMessageToAgentListener {
 		};
 
 		Logger.Fatal("Agent authentication failed: {Error}", errorMessage);
+		
+		PhantomLogger.Dispose();
 		Environment.Exit(1);
 
-		return Task.CompletedTask;
+		return Task.FromResult(NoReply.Instance);
 	}
 	
-	public async Task HandleConfigureInstance(ConfigureInstanceMessage message) {
-		await socket.SendSimpleReply(message, await agent.InstanceSessionManager.Configure(message.Configuration));
+	private Task<InstanceActionResult<ConfigureInstanceResult>> HandleConfigureInstance(ConfigureInstanceMessage message, bool alwaysReportStatus) {
+		return agent.InstanceSessionManager.Configure(message.Configuration, message.LaunchProperties, message.LaunchNow, alwaysReportStatus);
+	}
+	
+	public async Task<InstanceActionResult<ConfigureInstanceResult>> HandleConfigureInstance(ConfigureInstanceMessage message) {
+		return await HandleConfigureInstance(message, alwaysReportStatus: false);
 	}
 
-	public async Task HandleLaunchInstance(LaunchInstanceMessage message) {
-		await socket.SendSimpleReply(message, await agent.InstanceSessionManager.Launch(message.InstanceGuid));
+	public async Task<InstanceActionResult<LaunchInstanceResult>> HandleLaunchInstance(LaunchInstanceMessage message) {
+		return await agent.InstanceSessionManager.Launch(message.InstanceGuid);
 	}
 
-	public async Task HandleStopInstance(StopInstanceMessage message) {
-		await socket.SendSimpleReply(message, await agent.InstanceSessionManager.Stop(message.InstanceGuid));
+	public async Task<InstanceActionResult<StopInstanceResult>> HandleStopInstance(StopInstanceMessage message) {
+		return await agent.InstanceSessionManager.Stop(message.InstanceGuid, message.StopStrategy);
 	}
 
-	public async Task HandleSendCommandToInstance(SendCommandToInstanceMessage message) {
-		await socket.SendSimpleReply(message, await agent.InstanceSessionManager.SendCommand(message.InstanceGuid, message.Command));
+	public async Task<InstanceActionResult<SendCommandToInstanceResult>> HandleSendCommandToInstance(SendCommandToInstanceMessage message) {
+		return await agent.InstanceSessionManager.SendCommand(message.InstanceGuid, message.Command);
+	}
+
+	public Task<NoReply> HandleReply(ReplyMessage message) {
+		connection.Receive(message);
+		return Task.FromResult(NoReply.Instance);
 	}
 }

Agent/Phantom.Agent/AgentKey.cs

@@ -0,0 +1,60 @@
+using NetMQ;
+using Phantom.Common.Data;
+using Phantom.Common.Logging;
+using Phantom.Utils.Cryptography;
+using Phantom.Utils.IO;
+using Serilog;
+
+namespace Phantom.Agent;
+
+static class AgentKey {
+	private static ILogger Logger { get; } = PhantomLogger.Create(nameof(AgentKey));
+
+	public static Task<(NetMQCertificate, AuthToken)?> Load(string? agentKeyToken, string? agentKeyFilePath) {
+		if (agentKeyFilePath != null) {
+			return LoadFromFile(agentKeyFilePath);
+		}
+		else if (agentKeyToken != null) {
+			return Task.FromResult(LoadFromToken(agentKeyToken));
+		}
+		else {
+			throw new InvalidOperationException();
+		}
+	}
+
+	private static async Task<(NetMQCertificate, AuthToken)?> LoadFromFile(string agentKeyFilePath) {
+		if (!File.Exists(agentKeyFilePath)) {
+			Logger.Fatal("Missing agent key file: {AgentKeyFilePath}", agentKeyFilePath);
+			return null;
+		}
+
+		try {
+			Files.RequireMaximumFileSize(agentKeyFilePath, 64);
+			return LoadFromBytes(await File.ReadAllBytesAsync(agentKeyFilePath));
+		} catch (IOException e) {
+			Logger.Fatal("Error loading agent key from file: {AgentKeyFilePath}", agentKeyFilePath);
+			Logger.Fatal(e.Message);
+			return null;
+		} catch (Exception) {
+			Logger.Fatal("File does not contain a valid agent key: {AgentKeyFilePath}", agentKeyFilePath);
+			return null;
+		}
+	}
+
+	private static (NetMQCertificate, AuthToken)? LoadFromToken(string agentKey) {
+		try {
+			return LoadFromBytes(TokenGenerator.DecodeBytes(agentKey));
+		} catch (Exception) {
+			Logger.Fatal("Invalid agent key: {AgentKey}", agentKey);
+			return null;
+		}
+	}
+
+	private static (NetMQCertificate, AuthToken)? LoadFromBytes(byte[] agentKey) {
+		var (publicKey, agentToken) = ConnectionCommonKey.FromBytes(agentKey);
+		var controllerCertificate = NetMQCertificate.FromPublicKey(publicKey);
+		
+		Logger.Information("Loaded agent key.");
+		return (controllerCertificate, agentToken);
+	}
+}

Agent/Phantom.Agent/CertificateFile.cs

@@ -1,32 +0,0 @@
-using NetMQ;
-using Phantom.Common.Logging;
-using Phantom.Utils.IO;
-using Serilog;
-
-namespace Phantom.Agent;
-
-static class CertificateFile {
-	private static ILogger Logger { get; } = PhantomLogger.Create(typeof(CertificateFile));
-
-	public static async Task<NetMQCertificate?> LoadPublicKey(string publicKeyFilePath) {
-		if (!File.Exists(publicKeyFilePath)) {
-			Logger.Fatal("Cannot load server certificate, missing key file: {PublicKeyFilePath}", publicKeyFilePath);
-			return null;
-		}
-
-		try {
-			var publicKey = await LoadPublicKeyFromFile(publicKeyFilePath);
-			Logger.Information("Loaded server certificate.");
-			return publicKey;
-		} catch (Exception e) {
-			Logger.Fatal(e, "Error loading server certificate from key file: {PublicKeyFilePath}", publicKeyFilePath);
-			return null;
-		}
-	}
-
-	private static async Task<NetMQCertificate> LoadPublicKeyFromFile(string filePath) {
-		Files.RequireMaximumFileSize(filePath, 1024);
-		byte[] publicKey = await File.ReadAllBytesAsync(filePath);
-		return NetMQCertificate.FromPublicKey(publicKey);
-	}
-}

Agent/Phantom.Agent/GuidFile.cs

@@ -3,10 +3,10 @@ using Phantom.Common.Logging;
 using Phantom.Utils.IO;
 using Serilog;
 
-namespace Phantom.Agent; 
+namespace Phantom.Agent;
 
 static class GuidFile {
-	private static ILogger Logger { get; } = PhantomLogger.Create(typeof(GuidFile));
+	private static ILogger Logger { get; } = PhantomLogger.Create(nameof(GuidFile));
 
 	private const string GuidFileName = "agent.guid";
 	

Agent/Phantom.Agent/Phantom.Agent.csproj

@@ -1,18 +1,17 @@
 <Project Sdk="Microsoft.NET.Sdk">
   
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   
   <PropertyGroup>
     <OutputType>Exe</OutputType>
+    <SatelliteResourceLanguages>en</SatelliteResourceLanguages>
   </PropertyGroup>
   
   <ItemGroup>
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.IO\Phantom.Utils.IO.csproj" />
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.Runtime\Phantom.Utils.Runtime.csproj" />
+    <ProjectReference Include="..\..\Utils\Phantom.Utils\Phantom.Utils.csproj" />
     <ProjectReference Include="..\Phantom.Agent.Minecraft\Phantom.Agent.Minecraft.csproj" />
     <ProjectReference Include="..\Phantom.Agent.Services\Phantom.Agent.Services.csproj" />
   </ItemGroup>

Agent/Phantom.Agent/Program.cs

@@ -1,63 +1,90 @@
-using Phantom.Agent;
+using System.Reflection;
+using NetMQ;
+using Phantom.Agent;
 using Phantom.Agent.Rpc;
 using Phantom.Agent.Services;
 using Phantom.Agent.Services.Rpc;
 using Phantom.Common.Data.Agent;
 using Phantom.Common.Logging;
+using Phantom.Common.Messages.Agent;
+using Phantom.Common.Messages.Agent.ToController;
 using Phantom.Utils.Rpc;
+using Phantom.Utils.Rpc.Sockets;
 using Phantom.Utils.Runtime;
+using Phantom.Utils.Tasks;
 
-const int AgentVersion = 1;
+const int ProtocolVersion = 1;
 
-var cancellationTokenSource = new CancellationTokenSource();
+var shutdownCancellationTokenSource = new CancellationTokenSource();
+var shutdownCancellationToken = shutdownCancellationTokenSource.Token;
 
-PosixSignals.RegisterCancellation(cancellationTokenSource, static () => {
+PosixSignals.RegisterCancellation(shutdownCancellationTokenSource, static () => {
 	PhantomLogger.Root.InformationHeading("Stopping Phantom Panel agent...");
 });
 
+ThreadPool.SetMinThreads(workerThreads: 2, completionPortThreads: 1);
+
 try {
+	var fullVersion = AssemblyAttributes.GetFullVersion(Assembly.GetExecutingAssembly());
+
 	PhantomLogger.Root.InformationHeading("Initializing Phantom Panel agent...");
+	PhantomLogger.Root.Information("Agent version: {Version}", fullVersion);
 
-	var (serverHost, serverPort, javaSearchPath, authToken, authTokenFilePath, agentName, maxInstances, maxMemory, allowedServerPorts, allowedRconPorts) = Variables.LoadOrExit();
-	
-	AgentAuthToken agentAuthToken;
-	try {
-		agentAuthToken = authTokenFilePath == null ? new AgentAuthToken(authToken) : await AgentAuthToken.ReadFromFile(authTokenFilePath);
-	} catch (Exception e) {
-		PhantomLogger.Root.Fatal(e, "Error reading auth token.");
-		Environment.Exit(1);
-		return;
-	}
+	var (controllerHost, controllerPort, javaSearchPath, agentKeyToken, agentKeyFilePath, agentName, maxInstances, maxMemory, allowedServerPorts, allowedRconPorts, maxConcurrentBackupCompressionTasks) = Variables.LoadOrStop();
 
-	string serverPublicKeyPath = Path.GetFullPath("./secrets/agent.key");
-	var serverCertificate = await CertificateFile.LoadPublicKey(serverPublicKeyPath);
-	if (serverCertificate == null) {
-		Environment.Exit(1);
+	var agentKey = await AgentKey.Load(agentKeyToken, agentKeyFilePath);
+	if (agentKey == null) {
+		return 1;
 	}
 
 	var folders = new AgentFolders("./data", "./temp", javaSearchPath);
 	if (!folders.TryCreate()) {
-		Environment.Exit(1);
+		return 1;
 	}
 
 	var agentGuid = await GuidFile.CreateOrLoad(folders.DataFolderPath);
 	if (agentGuid == null) {
-		Environment.Exit(1);
-		return;
+		return 1;
 	}
 
-	var agentInfo = new AgentInfo(agentGuid.Value, agentName, AgentVersion, maxInstances, maxMemory, allowedServerPorts, allowedRconPorts);
-	var agentServices = new AgentServices(agentInfo, folders);
-
+	var (controllerCertificate, agentToken) = agentKey.Value;
+	var agentInfo = new AgentInfo(agentGuid.Value, agentName, ProtocolVersion, fullVersion, maxInstances, maxMemory, allowedServerPorts, allowedRconPorts);
+	
 	PhantomLogger.Root.InformationHeading("Launching Phantom Panel agent...");
 	
+	var rpcConfiguration = new RpcConfiguration(PhantomLogger.Create("Rpc"), PhantomLogger.Create<TaskManager>("Rpc"), controllerHost, controllerPort, controllerCertificate);
+	var rpcSocket = RpcClientSocket.Connect(rpcConfiguration, AgentMessageRegistries.Definitions, new RegisterAgentMessage(agentToken, agentInfo));
+
+	var agentServices = new AgentServices(agentInfo, folders, new AgentServiceConfiguration(maxConcurrentBackupCompressionTasks), new ControllerConnection(rpcSocket.Connection));
 	await agentServices.Initialize();
-	await RpcLauncher.Launch(new RpcConfiguration(PhantomLogger.Create("Rpc"), serverHost, serverPort, serverCertificate, cancellationTokenSource.Token), agentAuthToken, agentInfo, socket => new MessageListener(socket, agentServices, cancellationTokenSource));
-	await agentServices.Shutdown();
+
+	var rpcDisconnectSemaphore = new SemaphoreSlim(0, 1);
+	var rpcMessageListener = new MessageListener(rpcSocket.Connection, agentServices, shutdownCancellationTokenSource);
+	var rpcTask = RpcClientRuntime.Launch(rpcSocket, agentInfo, rpcMessageListener, rpcDisconnectSemaphore, shutdownCancellationToken);
+	try {
+		await rpcTask.WaitAsync(shutdownCancellationToken);
+	} finally {
+		shutdownCancellationTokenSource.Cancel();
+		await agentServices.Shutdown();
+
+		rpcDisconnectSemaphore.Release();
+		await rpcTask;
+		rpcDisconnectSemaphore.Dispose();
+		
+		NetMQConfig.Cleanup();
+	}
+
+	return 0;
 } catch (OperationCanceledException) {
-	// Ignore.
+	return 0;
+} catch (StopProcedureException) {
+	return 1;
+} catch (Exception e) {
+	PhantomLogger.Root.Fatal(e, "Caught exception in entry point.");
+	return 1;
 } finally {
-	cancellationTokenSource.Dispose();
+	shutdownCancellationTokenSource.Dispose();
+
 	PhantomLogger.Root.Information("Bye!");
 	PhantomLogger.Dispose();
 }

Agent/Phantom.Agent/Variables.cs

@@ -6,32 +6,34 @@ using Phantom.Utils.Runtime;
 namespace Phantom.Agent;
 
 sealed record Variables(
-	string ServerHost,
-	ushort ServerPort,
+	string ControllerHost,
+	ushort ControllerPort,
 	string JavaSearchPath,
-	string? AuthToken,
-	string? AuthTokenFilePath,
+	string? AgentKeyToken,
+	string? AgentKeyFilePath,
 	string AgentName,
 	ushort MaxInstances,
 	RamAllocationUnits MaxMemory,
 	AllowedPorts AllowedServerPorts,
-	AllowedPorts AllowedRconPorts
+	AllowedPorts AllowedRconPorts,
+	ushort MaxConcurrentBackupCompressionTasks
 ) {
 	private static Variables LoadOrThrow() {
-		var (authToken, authTokenFilePath) = EnvironmentVariables.GetEitherString("SERVER_AUTH_TOKEN", "SERVER_AUTH_TOKEN_FILE").OrThrow;
-		var javaSearchPath = EnvironmentVariables.GetString("JAVA_SEARCH_PATH").OrGetDefault(GetDefaultJavaSearchPath);
+		var (agentKeyToken, agentKeyFilePath) = EnvironmentVariables.GetEitherString("AGENT_KEY", "AGENT_KEY_FILE").Require;
+		var javaSearchPath = EnvironmentVariables.GetString("JAVA_SEARCH_PATH").WithDefaultGetter(GetDefaultJavaSearchPath);
 
 		return new Variables(
-			EnvironmentVariables.GetString("SERVER_HOST").OrThrow,
-			EnvironmentVariables.GetPortNumber("SERVER_PORT").OrDefault(9401),
+			EnvironmentVariables.GetString("CONTROLLER_HOST").Require,
+			EnvironmentVariables.GetPortNumber("CONTROLLER_PORT").WithDefault(9401),
 			javaSearchPath,
-			authToken,
-			authTokenFilePath,
-			EnvironmentVariables.GetString("AGENT_NAME").OrThrow,
-			(ushort) EnvironmentVariables.GetInteger("MAX_INSTANCES", min: 1, max: 10000).OrThrow,
-			EnvironmentVariables.GetString("MAX_MEMORY").MapParse(RamAllocationUnits.FromString).OrThrow,
-			EnvironmentVariables.GetString("ALLOWED_SERVER_PORTS").MapParse(AllowedPorts.FromString).OrThrow,
-			EnvironmentVariables.GetString("ALLOWED_RCON_PORTS").MapParse(AllowedPorts.FromString).OrThrow
+			agentKeyToken,
+			agentKeyFilePath,
+			EnvironmentVariables.GetString("AGENT_NAME").Require,
+			(ushort) EnvironmentVariables.GetInteger("MAX_INSTANCES", min: 1, max: 10000).Require,
+			EnvironmentVariables.GetString("MAX_MEMORY").MapParse(RamAllocationUnits.FromString).Require,
+			EnvironmentVariables.GetString("ALLOWED_SERVER_PORTS").MapParse(AllowedPorts.FromString).Require,
+			EnvironmentVariables.GetString("ALLOWED_RCON_PORTS").MapParse(AllowedPorts.FromString).Require,
+			(ushort) EnvironmentVariables.GetInteger("MAX_CONCURRENT_BACKUP_COMPRESSION_TASKS", min: 1, max: 10000).WithDefault(1)
 		);
 	}
 
@@ -39,13 +41,12 @@ sealed record Variables(
 		return JavaRuntimeDiscovery.GetSystemSearchPath() ?? throw new Exception("Could not automatically determine the path to Java installations on this system. Please set the JAVA_SEARCH_PATH environment variable to the folder containing Java installations.");
 	}
 
-	public static Variables LoadOrExit() {
+	public static Variables LoadOrStop() {
 		try {
 			return LoadOrThrow();
 		} catch (Exception e) {
 			PhantomLogger.Root.Fatal(e.Message);
-			Environment.Exit(1);
-			throw;
+			throw StopProcedureException.Instance;
 		}
 	}
 }

Common/Phantom.Common.Data.Tests/AllowedPortsTests.cs

@@ -1,6 +1,6 @@
 using NUnit.Framework;
 
-namespace Phantom.Common.Data.Tests; 
+namespace Phantom.Common.Data.Tests;
 
 [TestFixture]
 public sealed class AllowedPortsTests {

Common/Phantom.Common.Data.Tests/Phantom.Common.Data.Tests.csproj

@@ -1,7 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
@@ -11,11 +10,10 @@
   </PropertyGroup>
   
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.2" />
-    <PackageReference Include="NUnit" Version="3.13.3" />
-    <PackageReference Include="NUnit3TestAdapter" Version="4.2.1" />
-    <PackageReference Include="NUnit.Analyzers" Version="3.3.0" />
-    <PackageReference Include="coverlet.collector" Version="3.1.2" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="NUnit" />
+    <PackageReference Include="NUnit3TestAdapter" />
+    <PackageReference Include="NUnit.Analyzers" />
   </ItemGroup>
   
   <ItemGroup>

Common/Phantom.Common.Data.Web/AuditLog/AuditLogEventType.cs

@@ -0,0 +1,47 @@
+namespace Phantom.Common.Data.Web.AuditLog;
+
+public enum AuditLogEventType {
+	AdministratorUserCreated,
+	AdministratorUserModified,
+	UserLoggedIn,
+	UserLoggedOut,
+	UserCreated,
+	UserPasswordChanged,
+	UserRolesChanged,
+	UserDeleted,
+	InstanceCreated,
+	InstanceEdited,
+	InstanceLaunched,
+	InstanceStopped,
+	InstanceCommandExecuted
+}
+
+public static class AuditLogEventTypeExtensions {
+	private static readonly Dictionary<AuditLogEventType, AuditLogSubjectType> SubjectTypes = new () {
+		{ AuditLogEventType.AdministratorUserCreated,  AuditLogSubjectType.User },
+		{ AuditLogEventType.AdministratorUserModified, AuditLogSubjectType.User },
+		{ AuditLogEventType.UserLoggedIn,              AuditLogSubjectType.User },
+		{ AuditLogEventType.UserLoggedOut,             AuditLogSubjectType.User },
+		{ AuditLogEventType.UserCreated,               AuditLogSubjectType.User },
+		{ AuditLogEventType.UserPasswordChanged,       AuditLogSubjectType.User },
+		{ AuditLogEventType.UserRolesChanged,          AuditLogSubjectType.User },
+		{ AuditLogEventType.UserDeleted,               AuditLogSubjectType.User },
+		{ AuditLogEventType.InstanceCreated,           AuditLogSubjectType.Instance },
+		{ AuditLogEventType.InstanceEdited,            AuditLogSubjectType.Instance },
+		{ AuditLogEventType.InstanceLaunched,          AuditLogSubjectType.Instance },
+		{ AuditLogEventType.InstanceStopped,           AuditLogSubjectType.Instance },
+		{ AuditLogEventType.InstanceCommandExecuted,   AuditLogSubjectType.Instance }
+	};
+
+	static AuditLogEventTypeExtensions() {
+		foreach (var eventType in Enum.GetValues<AuditLogEventType>()) {
+			if (!SubjectTypes.ContainsKey(eventType)) {
+				throw new Exception("Missing mapping from " + eventType + " to a subject type.");
+			}
+		}
+	}
+
+	public static AuditLogSubjectType GetSubjectType(this AuditLogEventType type) {
+		return SubjectTypes[type];
+	}
+}