Add Fabric support

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

@@ -9,9 +9,9 @@ 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) {
@@ -34,7 +34,7 @@ public abstract class BaseLauncher {
 
 		ServerJarInfo? serverJar;
 		try {
-			serverJar = await PrepareServerJar(logger, vanillaServerJarPath, instanceProperties.InstanceFolder, cancellationToken);
+			serverJar = await PrepareServerJar(logger, vanillaServerJarPath, cancellationToken);
 		} catch (OperationCanceledException) {
 			throw;
 		} catch (Exception e) {
@@ -103,7 +103,7 @@ public abstract class BaseLauncher {
 
 	private protected virtual void CustomizeJvmArguments(JvmArgumentBuilder arguments) {}
 
-	private protected virtual Task<ServerJarInfo> PrepareServerJar(ILogger logger, string serverJarPath, string instanceFolderPath, CancellationToken cancellationToken) {
+	private protected virtual Task<ServerJarInfo> PrepareServerJar(ILogger logger, string serverJarPath, CancellationToken cancellationToken) {
 		return Task.FromResult(new ServerJarInfo(serverJarPath));
 	}
 

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/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.Services/Instances/Instance.cs

@@ -18,9 +18,10 @@ sealed class Instance : IDisposable {
 		return prefix[..prefix.IndexOf('-')] + "/" + Interlocked.Increment(ref loggerSequenceId);
 	}
 
-	public InstanceConfiguration Configuration { get; private set; }
 	private InstanceServices Services { get; }
-	private BaseLauncher Launcher { get; set; }
+	
+	public InstanceConfiguration Configuration { get; private set; }
+	private IServerLauncher Launcher { get; set; }
 
 	private readonly string shortName;
 	private readonly ILogger logger;
@@ -35,12 +36,12 @@ sealed class Instance : IDisposable {
 	
 	public event EventHandler? IsRunningChanged; 
 
-	public Instance(InstanceConfiguration configuration, InstanceServices services, BaseLauncher launcher) {
+	public Instance(InstanceServices services, InstanceConfiguration configuration, IServerLauncher launcher) {
 		this.shortName = GetLoggerName(configuration.InstanceGuid);
 		this.logger = PhantomLogger.Create<Instance>(shortName);
 
-		this.Configuration = configuration;
 		this.Services = services;
+		this.Configuration = configuration;
 		this.Launcher = launcher;
 		
 		this.currentState = new InstanceNotRunningState();
@@ -100,7 +101,7 @@ sealed class Instance : IDisposable {
 		return newStateAndResult.Result;
 	}
 
-	public async Task Reconfigure(InstanceConfiguration configuration, BaseLauncher launcher, CancellationToken cancellationToken) {
+	public async Task Reconfigure(InstanceConfiguration configuration, IServerLauncher launcher, CancellationToken cancellationToken) {
 		await stateTransitioningActionSemaphore.WaitAsync(cancellationToken);
 		try {
 			Configuration = configuration;
@@ -153,7 +154,7 @@ sealed class Instance : IDisposable {
 		private readonly Instance instance;
 		private readonly CancellationToken shutdownCancellationToken;
 		
-		public InstanceContextImpl(Instance instance, CancellationToken shutdownCancellationToken) : base(instance.Configuration, instance.Launcher, instance.Services) {
+		public InstanceContextImpl(Instance instance, CancellationToken shutdownCancellationToken) : base(instance.Services, instance.Configuration, instance.Launcher) {
 			this.instance = instance;
 			this.shutdownCancellationToken = shutdownCancellationToken;
 		}

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

@@ -6,17 +6,17 @@ using Serilog;
 namespace Phantom.Agent.Services.Instances;
 
 abstract class InstanceContext {
-	public InstanceConfiguration Configuration { get; }
-	public BaseLauncher Launcher { get; }
 	public InstanceServices Services { get; }
+	public InstanceConfiguration Configuration { get; }
+	public IServerLauncher Launcher { get; }
 	
 	public abstract ILogger Logger { get; }
 	public abstract string ShortName { get; }
 
-	protected InstanceContext(InstanceConfiguration configuration, BaseLauncher launcher, InstanceServices services) {
+	protected InstanceContext(InstanceServices services, InstanceConfiguration configuration, IServerLauncher launcher) {
+		Services = services;
 		Configuration = configuration;
 		Launcher = launcher;
-		Services = services;
 	}
 
 	public abstract void SetStatus(IInstanceStatus newStatus);

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

@@ -27,7 +27,6 @@ sealed class InstanceSessionManager : IDisposable {
 	private readonly AgentInfo agentInfo;
 	private readonly string basePath;
 
-	private readonly MinecraftServerExecutables minecraftServerExecutables;
 	private readonly InstanceServices instanceServices;
 	private readonly Dictionary<Guid, Instance> instances = new ();
 
@@ -38,11 +37,12 @@ sealed class InstanceSessionManager : IDisposable {
 	public InstanceSessionManager(AgentInfo agentInfo, AgentFolders agentFolders, JavaRuntimeRepository javaRuntimeRepository, TaskManager taskManager, BackupManager backupManager) {
 		this.agentInfo = agentInfo;
 		this.basePath = agentFolders.InstancesFolderPath;
-		this.minecraftServerExecutables = new MinecraftServerExecutables(agentFolders.ServerExecutableFolderPath);
 		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(taskManager, portManager, backupManager, launchServices);
 	}
 
@@ -94,7 +94,11 @@ sealed class InstanceSessionManager : IDisposable {
 				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);
@@ -105,7 +109,7 @@ sealed class InstanceSessionManager : IDisposable {
 				}
 			}
 			else {
-				instances[instanceGuid] = instance = new Instance(configuration, instanceServices, launcher);
+				instances[instanceGuid] = instance = new Instance(instanceServices, configuration, launcher);
 				Logger.Information("Created instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, configuration.InstanceGuid);
 				
 				instance.ReportLastStatus();

Common/Phantom.Common.Data/Minecraft/MinecraftServerKind.cs

@@ -1,5 +1,6 @@
 namespace Phantom.Common.Data.Minecraft; 
 
 public enum MinecraftServerKind : ushort {
-	Vanilla = 1
+	Vanilla = 1,
+	Fabric = 2
 }