Move fetching server jar download information exclusively to the Server

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

@@ -1,6 +1,7 @@
 using System.Collections.Immutable;
 using Phantom.Agent.Minecraft.Java;
 using Phantom.Agent.Minecraft.Properties;
+using Phantom.Common.Data.Instance;
 
 namespace Phantom.Agent.Minecraft.Instance;
 
@@ -11,5 +12,6 @@ public sealed record InstanceProperties(
 	ImmutableArray<string> JvmArguments,
 	string InstanceFolder,
 	string ServerVersion,
-	ServerProperties ServerProperties
+	ServerProperties ServerProperties,
+	InstanceLaunchProperties LaunchProperties
 );

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

@@ -25,7 +25,7 @@ public abstract class BaseLauncher {
 			return new LaunchResult.InvalidJvmArguments();
 		}
 
-		var vanillaServerJarPath = await services.ServerExecutables.DownloadAndGetPath(instanceProperties.ServerVersion, downloadProgressEventHandler, cancellationToken);
+		var vanillaServerJarPath = await services.ServerExecutables.DownloadAndGetPath(instanceProperties.LaunchProperties.ServerDownloadInfo, instanceProperties.ServerVersion, downloadProgressEventHandler, cancellationToken);
 		if (vanillaServerJarPath == null) {
 			return new LaunchResult.CouldNotDownloadMinecraftServer();
 		}

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

@@ -17,6 +17,7 @@
     <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.Runtime\Phantom.Utils.Runtime.csproj" />
   </ItemGroup>
 
 </Project>

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

@@ -1,6 +1,6 @@
 using System.Security.Cryptography;
+using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Logging;
-using Phantom.Common.Minecraft;
 using Phantom.Utils.Cryptography;
 using Phantom.Utils.IO;
 using Phantom.Utils.Runtime;
@@ -11,8 +11,6 @@ namespace Phantom.Agent.Minecraft.Server;
 sealed class MinecraftServerExecutableDownloader {
 	private static readonly ILogger Logger = PhantomLogger.Create<MinecraftServerExecutableDownloader>();
 
-	private readonly MinecraftVersions minecraftVersions;
-	
 	public Task<string?> Task { get; }
 	public event EventHandler<DownloadProgressEventArgs>? DownloadProgress;
 	public event EventHandler? Completed;
@@ -20,11 +18,9 @@ sealed class MinecraftServerExecutableDownloader {
 	private readonly CancellationTokenSource cancellationTokenSource = new ();
 	private int listeners = 0;
 
-	public MinecraftServerExecutableDownloader(MinecraftVersions minecraftVersions, string version, string filePath, MinecraftServerExecutableDownloadListener listener) {
+	public MinecraftServerExecutableDownloader(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath, MinecraftServerExecutableDownloadListener listener) {
-		this.minecraftVersions = minecraftVersions;
-		
 		Register(listener);
-		Task = DownloadAndGetPath(version, filePath);
+		Task = DownloadAndGetPath(fileDownloadInfo, minecraftVersion, filePath);
 		Task.ContinueWith(OnCompleted, TaskScheduler.Default);
 	}
 
@@ -72,33 +68,26 @@ sealed class MinecraftServerExecutableDownloader {
 		}
 	}
 
-	private async Task<string?> DownloadAndGetPath(string version, string filePath) {
+	private async Task<string?> DownloadAndGetPath(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath) {
-		Logger.Information("Downloading server version {Version}...", version);
-
 		string tmpFilePath = filePath + ".tmp";
 
 		var cancellationToken = cancellationTokenSource.Token;
 		try {
-			var serverExecutableInfo = await minecraftVersions.GetServerExecutableInfo(version, cancellationToken);
+			Logger.Information("Downloading server version {Version} from: {Url} ({Size})", minecraftVersion, fileDownloadInfo.DownloadUrl, fileDownloadInfo.Size.ToHumanReadable(decimalPlaces: 1));
-			if (serverExecutableInfo == null) {
-				return null;
-			}
-
-			Logger.Information("Downloading server executable from: {Url} ({Size})", serverExecutableInfo.DownloadUrl, serverExecutableInfo.Size.ToHumanReadable(decimalPlaces: 1));
 			try {
 				using var http = new HttpClient();
-				await FetchServerExecutableFile(http, new DownloadProgressCallback(this), serverExecutableInfo, tmpFilePath, cancellationToken);
+				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;
@@ -110,17 +99,17 @@ sealed class MinecraftServerExecutableDownloader {
 		}
 	}
 
-	private static async Task FetchServerExecutableFile(HttpClient http, DownloadProgressCallback progressCallback, MinecraftServerExecutableInfo 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;
@@ -129,8 +118,8 @@ sealed class MinecraftServerExecutableDownloader {
 			throw StopProcedureException.Instance;
 		}
 
-		if (!downloadedFileHash.Equals(info.Hash)) {
+		if (!downloadedFileHash.Equals(fileDownloadInfo.Hash)) {
-			Logger.Error("Downloaded server executable has mismatched SHA1 hash. Expected {Expected}, got {Actual}.", info.Hash, downloadedFileHash);
+			Logger.Error("Downloaded server executable has mismatched SHA1 hash. Expected {Expected}, got {Actual}.", fileDownloadInfo.Hash, downloadedFileHash);
 			throw StopProcedureException.Instance;
 		}
 	}

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

@@ -1,33 +1,37 @@
 using System.Text.RegularExpressions;
+using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Logging;
-using Phantom.Common.Minecraft;
 using Phantom.Utils.IO;
 using Serilog;
 
 namespace Phantom.Agent.Minecraft.Server;
 
-public sealed partial class MinecraftServerExecutables : IDisposable {
+public sealed partial class MinecraftServerExecutables {
 	private static readonly ILogger Logger = PhantomLogger.Create<MinecraftServerExecutables>();
 
 	[GeneratedRegex(@"[^a-zA-Z0-9_\-\.]", RegexOptions.Compiled)]
 	private static partial Regex VersionFolderSanitizeRegex();
 
 	private readonly string basePath;
-	private readonly MinecraftVersions minecraftVersions = new ();
 	private readonly Dictionary<string, MinecraftServerExecutableDownloader> runningDownloadersByVersion = new ();
 
 	public MinecraftServerExecutables(string basePath) {
 		this.basePath = basePath;
 	}
 
-	internal async Task<string?> DownloadAndGetPath(string version, EventHandler<DownloadProgressEventArgs> progressEventHandler, CancellationToken cancellationToken) {
+	internal async Task<string?> DownloadAndGetPath(FileDownloadInfo? fileDownloadInfo, string minecraftVersion, EventHandler<DownloadProgressEventArgs> progressEventHandler, CancellationToken cancellationToken) {
-		string serverExecutableFolderPath = Path.Combine(basePath, VersionFolderSanitizeRegex().Replace(version, "_"));
+		string serverExecutableFolderPath = Path.Combine(basePath, VersionFolderSanitizeRegex().Replace(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 {
 			Directories.Create(serverExecutableFolderPath, Chmod.URWX_GRX);
 		} catch (Exception e) {
@@ -39,26 +43,22 @@ public sealed partial class MinecraftServerExecutables : IDisposable {
 		MinecraftServerExecutableDownloadListener listener = new (progressEventHandler, cancellationToken);
 
 		lock (this) {
-			if (runningDownloadersByVersion.TryGetValue(version, out downloader)) {
+			if (runningDownloadersByVersion.TryGetValue(minecraftVersion, out downloader)) {
-				Logger.Information("A download for server version {Version} is already running, waiting for it to finish...", version);
+				Logger.Information("A download for server version {Version} is already running, waiting for it to finish...", minecraftVersion);
 				downloader.Register(listener);
 			}
 			else {
-				downloader = new MinecraftServerExecutableDownloader(minecraftVersions, 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;
 			}
 		}
 
 		return await downloader.Task.WaitAsync(cancellationToken);
 	}
-
-	public void Dispose() {
-		minecraftVersions.Dispose();
-	}
 }

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

@@ -71,7 +71,7 @@ sealed class InstanceSessionManager : IDisposable {
 		});
 	}
 
-	public async Task<InstanceActionResult<ConfigureInstanceResult>> Configure(InstanceConfiguration configuration) {
+	public async Task<InstanceActionResult<ConfigureInstanceResult>> Configure(InstanceConfiguration configuration, InstanceLaunchProperties launchProperties) {
 		return await AcquireSemaphoreAndRun(async () => {
 			var instanceGuid = configuration.InstanceGuid;
 			var instanceFolder = Path.Combine(basePath, instanceGuid.ToString());
@@ -90,7 +90,8 @@ sealed class InstanceSessionManager : IDisposable {
 				configuration.JvmArguments,
 				instanceFolder,
 				configuration.MinecraftVersion,
-				new ServerProperties(configuration.ServerPort, configuration.RconPort)
+				new ServerProperties(configuration.ServerPort, configuration.RconPort),
+				launchProperties
 			);
 
 			BaseLauncher launcher = new VanillaLauncher(properties);
@@ -179,7 +180,6 @@ sealed class InstanceSessionManager : IDisposable {
 
 	public void Dispose() {
 		DisposeAllInstances();
-		minecraftServerExecutables.Dispose();
 		shutdownCancellationTokenSource.Dispose();
 		semaphore.Dispose();
 	}

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

@@ -1,4 +1,5 @@
 using Phantom.Agent.Rpc;
+using Phantom.Common.Data.Instance;
 using Phantom.Common.Data.Replies;
 using Phantom.Common.Logging;
 using Phantom.Common.Messages;
@@ -26,12 +27,15 @@ public sealed class MessageListener : IMessageToAgentListener {
 	public async Task<NoReply> HandleRegisterAgentSuccess(RegisterAgentSuccessMessage message) {
 		Logger.Information("Agent authentication successful.");
 
-		foreach (var instanceInfo in message.InitialInstances) {
+		void ShutdownAfterConfigurationFailed(InstanceConfiguration configuration) {
-			var result = await agent.InstanceSessionManager.Configure(instanceInfo);
+			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);
 			if (!result.Is(ConfigureInstanceResult.Success)) {
-				Logger.Fatal("Unable to configure instance \"{Name}\" (GUID {Guid}), shutting down.", instanceInfo.InstanceName, instanceInfo.InstanceGuid);
+				ShutdownAfterConfigurationFailed(configureInstanceMessage.Configuration);
-
-				shutdownTokenSource.Cancel();
 				return NoReply.Instance;
 			}
 		}
@@ -56,7 +60,7 @@ public sealed class MessageListener : IMessageToAgentListener {
 	}
 	
 	public async Task<InstanceActionResult<ConfigureInstanceResult>> HandleConfigureInstance(ConfigureInstanceMessage message) {
-		return await agent.InstanceSessionManager.Configure(message.Configuration);
+		return await agent.InstanceSessionManager.Configure(message.Configuration, message.LaunchProperties);
 	}
 
 	public async Task<InstanceActionResult<LaunchInstanceResult>> HandleLaunchInstance(LaunchInstanceMessage message) {

Common/Phantom.Common.Data/Instance/InstanceLaunchProperties.cs

@@ -0,0 +1,9 @@
+using MemoryPack;
+using Phantom.Common.Data.Minecraft;
+
+namespace Phantom.Common.Data.Instance; 
+
+[MemoryPackable]
+public sealed partial record InstanceLaunchProperties(
+	[property: MemoryPackOrder(0)] FileDownloadInfo? ServerDownloadInfo
+);

Common/Phantom.Common.Data/Minecraft/FileDownloadInfo.cs

@@ -0,0 +1,30 @@
+using MemoryPack;
+using Phantom.Utils.Cryptography;
+using Phantom.Utils.IO;
+
+namespace Phantom.Common.Data.Minecraft; 
+
+[MemoryPackable]
+public sealed partial class FileDownloadInfo {
+	[MemoryPackOrder(0)]
+	public string DownloadUrl { get; }
+	
+	[MemoryPackOrder(1)]
+	[MemoryPackInclude]
+	private readonly string hash;
+	
+	[MemoryPackIgnore]
+	public Sha1String Hash => Sha1String.FromString(hash);
+	
+	[MemoryPackOrder(2)]
+	public FileSize Size { get; }
+	
+	public FileDownloadInfo(string downloadUrl, Sha1String hash, FileSize size) : this(downloadUrl, hash.ToString(), size) {}
+
+	[MemoryPackConstructor]
+	private FileDownloadInfo(string downloadUrl, string hash, FileSize size) {
+		this.DownloadUrl = downloadUrl;
+		this.hash = hash;
+		this.Size = size;
+	}
+}

Common/Phantom.Common.Messages/ToAgent/ConfigureInstanceMessage.cs

@@ -6,7 +6,8 @@ namespace Phantom.Common.Messages.ToAgent;
 
 [MemoryPackable]
 public sealed partial record ConfigureInstanceMessage(
-	[property: MemoryPackOrder(0)] InstanceConfiguration Configuration
+	[property: MemoryPackOrder(0)] InstanceConfiguration Configuration,
+	[property: MemoryPackOrder(1)] InstanceLaunchProperties LaunchProperties
 ) : IMessageToAgent<InstanceActionResult<ConfigureInstanceResult>> {
 	public Task<InstanceActionResult<ConfigureInstanceResult>> Accept(IMessageToAgentListener listener) {
 		return listener.HandleConfigureInstance(this);

Common/Phantom.Common.Messages/ToAgent/RegisterAgentSuccessMessage.cs

@@ -1,13 +1,12 @@
 using System.Collections.Immutable;
 using MemoryPack;
-using Phantom.Common.Data.Instance;
 using Phantom.Utils.Rpc.Message;
 
 namespace Phantom.Common.Messages.ToAgent;
 
 [MemoryPackable]
 public sealed partial record RegisterAgentSuccessMessage(
-	[property: MemoryPackOrder(0)] ImmutableArray<InstanceConfiguration> InitialInstances
+	[property: MemoryPackOrder(0)] ImmutableArray<ConfigureInstanceMessage> InitialInstanceConfigurations
 ) : IMessageToAgent {
 	public Task<NoReply> Accept(IMessageToAgentListener listener) {
 		return listener.HandleRegisterAgentSuccess(this);

Common/Phantom.Common.Minecraft/MinecraftServerExecutableInfo.cs

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

Common/Phantom.Common.Minecraft/Phantom.Common.Minecraft.csproj

@@ -6,11 +6,4 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
   
-  <ItemGroup>
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.IO\Phantom.Utils.IO.csproj" />
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.Runtime\Phantom.Utils.Runtime.csproj" />
-    <ProjectReference Include="..\Phantom.Common.Data\Phantom.Common.Data.csproj" />
-    <ProjectReference Include="..\Phantom.Common.Logging\Phantom.Common.Logging.csproj" />
-  </ItemGroup>
-  
 </Project>

PhantomPanel.sln

@@ -36,6 +36,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Phantom.Server.Database", "
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Phantom.Server.Database.Postgres", "Server\Phantom.Server.Database.Postgres\Phantom.Server.Database.Postgres.csproj", "{81625B4A-3DB6-48BD-A739-D23DA02107D1}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Phantom.Server.Minecraft", "Server\Phantom.Server.Minecraft\Phantom.Server.Minecraft.csproj", "{4B3B73E6-48DD-4846-87FD-DFB86619B67C}"
+EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Phantom.Server.Rpc", "Server\Phantom.Server.Rpc\Phantom.Server.Rpc.csproj", "{79312D72-44E0-431D-96A4-4C0A066B9671}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Phantom.Server.Services", "Server\Phantom.Server.Services\Phantom.Server.Services.csproj", "{90F0F1B1-EB0A-49C9-8DF0-1153A87F77C9}"
@@ -118,6 +120,10 @@ Global
 		{81625B4A-3DB6-48BD-A739-D23DA02107D1}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{81625B4A-3DB6-48BD-A739-D23DA02107D1}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{81625B4A-3DB6-48BD-A739-D23DA02107D1}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4B3B73E6-48DD-4846-87FD-DFB86619B67C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4B3B73E6-48DD-4846-87FD-DFB86619B67C}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4B3B73E6-48DD-4846-87FD-DFB86619B67C}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4B3B73E6-48DD-4846-87FD-DFB86619B67C}.Release|Any CPU.Build.0 = Release|Any CPU
 		{79312D72-44E0-431D-96A4-4C0A066B9671}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{79312D72-44E0-431D-96A4-4C0A066B9671}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{79312D72-44E0-431D-96A4-4C0A066B9671}.Release|Any CPU.ActiveCfg = Release|Any CPU
@@ -184,6 +190,7 @@ Global
 		{A0F1C595-96B6-4DBF-8C16-6B99223F8F35} = {8AC8FB6C-033A-4626-820F-ED0F908756B2}
 		{E3AD566F-384A-489A-A3BB-EA3BA400C18C} = {8AC8FB6C-033A-4626-820F-ED0F908756B2}
 		{81625B4A-3DB6-48BD-A739-D23DA02107D1} = {8AC8FB6C-033A-4626-820F-ED0F908756B2}
+		{4B3B73E6-48DD-4846-87FD-DFB86619B67C} = {8AC8FB6C-033A-4626-820F-ED0F908756B2}
 		{79312D72-44E0-431D-96A4-4C0A066B9671} = {8AC8FB6C-033A-4626-820F-ED0F908756B2}
 		{90F0F1B1-EB0A-49C9-8DF0-1153A87F77C9} = {8AC8FB6C-033A-4626-820F-ED0F908756B2}
 		{7CA2E5FE-E507-4DC6-930C-E18711A9F856} = {8AC8FB6C-033A-4626-820F-ED0F908756B2}

Server/Phantom.Server.Minecraft/MinecraftVersions.cs

@@ -9,7 +9,7 @@ using Phantom.Utils.IO;
 using Phantom.Utils.Runtime;
 using Serilog;
 
-namespace Phantom.Common.Minecraft;
+namespace Phantom.Server.Minecraft;
 
 public sealed class MinecraftVersions : IDisposable {
 	private static readonly ILogger Logger = PhantomLogger.Create<MinecraftVersions>();
@@ -35,12 +35,7 @@ public sealed class MinecraftVersions : IDisposable {
 			return earlyResult;
 		}
 
-		try {
+		await cachedVersionsSemaphore.WaitAsync(cancellationToken);
-			await cachedVersionsSemaphore.WaitAsync(cancellationToken);
-		} catch (OperationCanceledException) {
-			return ImmutableArray<MinecraftVersion>.Empty;
-		}
-
 		try {
 			if (CachedVersionsUnlessExpired is {} racedResult) {
 				return racedResult;
@@ -64,7 +59,7 @@ public sealed class MinecraftVersions : IDisposable {
 		});
 	}
 
-	public async Task<MinecraftServerExecutableInfo?> GetServerExecutableInfo(string version, CancellationToken cancellationToken) {
+	public async Task<FileDownloadInfo?> GetServerExecutableInfo(string version, CancellationToken cancellationToken) {
 		return await FetchOrFailSilently(async () => {
 			var versions = await GetVersions(cancellationToken);
 			var versionObject = versions.FirstOrDefault(v => v.Id == version);
@@ -81,8 +76,6 @@ public sealed class MinecraftVersions : IDisposable {
 	private static async Task<T?> FetchOrFailSilently<T>(Func<Task<T?>> task) {
 		try {
 			return await task();
-		} catch (OperationCanceledException) {
-			return default;
 		} catch (StopProcedureException) {
 			return default;
 		} catch (Exception e) {
@@ -96,9 +89,7 @@ public sealed class MinecraftVersions : IDisposable {
 
 		try {
 			return await http.GetFromJsonAsync<JsonElement>(url, cancellationToken);
-		} catch (OperationCanceledException) {
+		} catch (HttpRequestException e) {
-			throw StopProcedureException.Instance;
-		}  catch (HttpRequestException e) {
 			Logger.Error(e, "Unable to download {Description}.", description);
 			throw StopProcedureException.Instance;
 		} catch (Exception e) {
@@ -117,7 +108,7 @@ public sealed class MinecraftVersions : IDisposable {
 			} catch (StopProcedureException) {}
 		}
 
-		return foundVersions.ToImmutable();
+		return foundVersions.MoveToImmutable();
 	}
 
 	private static MinecraftVersion GetVersionFromManifestEntry(JsonElement versionElement) {
@@ -148,7 +139,7 @@ public sealed class MinecraftVersions : IDisposable {
 		return new MinecraftVersion(id, type, url);
 	}
 
-	private static MinecraftServerExecutableInfo GetServerExecutableInfoFromMetadata(JsonElement versionMetadata) {
+	private static FileDownloadInfo GetServerExecutableInfoFromMetadata(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");
@@ -182,7 +173,7 @@ public sealed class MinecraftVersions : IDisposable {
 			throw StopProcedureException.Instance;
 		}
 
-		return new MinecraftServerExecutableInfo(url, hash, new FileSize(size));
+		return new FileDownloadInfo(url, hash, new FileSize(size));
 	}
 
 	private static JsonElement GetJsonPropertyOrThrow(JsonElement parentElement, string propertyKey, JsonValueKind expectedKind, string location) {

Server/Phantom.Server.Minecraft/Phantom.Server.Minecraft.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  
+  <PropertyGroup>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+  
+  <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.Runtime\Phantom.Utils.Runtime.csproj" />
+  </ItemGroup>
+
+</Project>

Server/Phantom.Server.Services/Agents/AgentManager.cs

@@ -82,7 +82,9 @@ public sealed class AgentManager {
 
 		Logger.Information("Registered agent \"{Name}\" (GUID {Guid}).", agent.Name, agent.Guid);
 
-		await connection.Send(new RegisterAgentSuccessMessage(instanceManager.GetInstanceConfigurationsForAgent(agent.Guid)));
+		var instanceConfigurations = await instanceManager.GetInstanceConfigurationsForAgent(agent.Guid);
+		await connection.Send(new RegisterAgentSuccessMessage(instanceConfigurations));
+		
 		return true;
 	}
 

Server/Phantom.Server.Services/Instances/AddOrEditInstanceResult.cs

@@ -5,17 +5,19 @@ public enum AddOrEditInstanceResult : byte {
 	Success,
 	InstanceNameMustNotBeEmpty,
 	InstanceMemoryMustNotBeZero,
+	MinecraftVersionDownloadInfoNotFound,
 	AgentNotFound
 }
 
 public static class AddOrEditInstanceResultExtensions {
 	public static string ToSentence(this AddOrEditInstanceResult reason) {
 		return reason switch {
-			AddOrEditInstanceResult.Success                     => "Success.",
+			AddOrEditInstanceResult.Success                              => "Success.",
-			AddOrEditInstanceResult.InstanceNameMustNotBeEmpty  => "Instance name must not be empty.",
+			AddOrEditInstanceResult.InstanceNameMustNotBeEmpty           => "Instance name must not be empty.",
-			AddOrEditInstanceResult.InstanceMemoryMustNotBeZero => "Memory must not be 0 MB.",
+			AddOrEditInstanceResult.InstanceMemoryMustNotBeZero          => "Memory must not be 0 MB.",
-			AddOrEditInstanceResult.AgentNotFound               => "Agent not found.",
+			AddOrEditInstanceResult.MinecraftVersionDownloadInfoNotFound => "Could not find download information for the selected Minecraft version.",
-			_                                                   => "Unknown error."
+			AddOrEditInstanceResult.AgentNotFound                        => "Agent not found.",
+			_                                                            => "Unknown error."
 		};
 	}
 }

Server/Phantom.Server.Services/Instances/InstanceManager.cs

@@ -10,6 +10,7 @@ using Phantom.Common.Messages.ToAgent;
 using Phantom.Common.Minecraft;
 using Phantom.Server.Database;
 using Phantom.Server.Database.Entities;
+using Phantom.Server.Minecraft;
 using Phantom.Server.Services.Agents;
 using Phantom.Utils.Collections;
 using Phantom.Utils.Events;
@@ -26,12 +27,14 @@ public sealed class InstanceManager {
 
 	private readonly CancellationToken cancellationToken;
 	private readonly AgentManager agentManager;
+	private readonly MinecraftVersions minecraftVersions;
 	private readonly DatabaseProvider databaseProvider;
 	private readonly SemaphoreSlim modifyInstancesSemaphore = new (1, 1);
 
-	public InstanceManager(ServiceConfiguration configuration, AgentManager agentManager, DatabaseProvider databaseProvider) {
+	public InstanceManager(ServiceConfiguration configuration, AgentManager agentManager, MinecraftVersions minecraftVersions, DatabaseProvider databaseProvider) {
 		this.cancellationToken = configuration.CancellationToken;
 		this.agentManager = agentManager;
+		this.minecraftVersions = minecraftVersions;
 		this.databaseProvider = databaseProvider;
 	}
 
@@ -73,6 +76,11 @@ public sealed class InstanceManager {
 			return InstanceActionResult.Concrete(AddOrEditInstanceResult.InstanceMemoryMustNotBeZero);
 		}
 		
+		var serverExecutableInfo = await minecraftVersions.GetServerExecutableInfo(configuration.MinecraftVersion, cancellationToken);
+		if (serverExecutableInfo == null) {
+			return InstanceActionResult.Concrete(AddOrEditInstanceResult.MinecraftVersionDownloadInfoNotFound);
+		}
+
 		InstanceActionResult<AddOrEditInstanceResult> result;
 		bool isNewInstance;
 
@@ -80,8 +88,9 @@ public sealed class InstanceManager {
 		try {
 			var instance = new Instance(configuration);
 			instances.ByGuid.AddOrReplace(instance.Configuration.InstanceGuid, instance, out var oldInstance);
-			
+
-			var reply = await agentManager.SendMessage<ConfigureInstanceMessage, InstanceActionResult<ConfigureInstanceResult>>(configuration.AgentGuid, new ConfigureInstanceMessage(configuration), TimeSpan.FromSeconds(10));
+			var message = new ConfigureInstanceMessage(configuration, new InstanceLaunchProperties(serverExecutableInfo));
+			var reply = await agentManager.SendMessage<ConfigureInstanceMessage, InstanceActionResult<ConfigureInstanceResult>>(configuration.AgentGuid, message, TimeSpan.FromSeconds(10));
 			
 			result = reply.DidNotReplyIfNull().Map(static result => result switch {
 				ConfigureInstanceResult.Success => AddOrEditInstanceResult.Success,
@@ -199,8 +208,15 @@ public sealed class InstanceManager {
 		return await SendInstanceActionMessage<SendCommandToInstanceMessage, SendCommandToInstanceResult>(instanceGuid, new SendCommandToInstanceMessage(instanceGuid, command));
 	}
 
-	internal ImmutableArray<InstanceConfiguration> GetInstanceConfigurationsForAgent(Guid agentGuid) {
+	internal async Task<ImmutableArray<ConfigureInstanceMessage>> GetInstanceConfigurationsForAgent(Guid agentGuid) {
-		return instances.ByGuid.ValuesCopy.Select(static instance => instance.Configuration).Where(configuration => configuration.AgentGuid == agentGuid).ToImmutableArray();
+		var configurationMessages = ImmutableArray.CreateBuilder<ConfigureInstanceMessage>();
+		
+		foreach (var configuration in instances.ByGuid.ValuesCopy.Select(static instance => instance.Configuration).Where(configuration => configuration.AgentGuid == agentGuid)) {
+			var serverExecutableInfo = await minecraftVersions.GetServerExecutableInfo(configuration.MinecraftVersion, cancellationToken);
+			configurationMessages.Add(new ConfigureInstanceMessage(configuration, new InstanceLaunchProperties(serverExecutableInfo)));
+		}
+
+		return configurationMessages.ToImmutable();
 	}
 
 	private sealed class ObservableInstances : ObservableState<ImmutableDictionary<Guid, Instance>> {

Server/Phantom.Server.Services/Phantom.Server.Services.csproj

@@ -16,6 +16,7 @@
     <ProjectReference Include="..\..\Utils\Phantom.Utils.Collections\Phantom.Utils.Collections.csproj" />
     <ProjectReference Include="..\..\Utils\Phantom.Utils.Events\Phantom.Utils.Events.csproj" />
     <ProjectReference Include="..\Phantom.Server.Database\Phantom.Server.Database.csproj" />
+    <ProjectReference Include="..\Phantom.Server.Minecraft\Phantom.Server.Minecraft.csproj" />
     <ProjectReference Include="..\Phantom.Server.Rpc\Phantom.Server.Rpc.csproj" />
   </ItemGroup>
 

Server/Phantom.Server.Web/Shared/InstanceAddOrEditForm.razor

@@ -1,5 +1,6 @@
 @using Phantom.Common.Data.Minecraft
 @using Phantom.Common.Minecraft
+@using Phantom.Server.Minecraft
 @using Phantom.Server.Services.Agents
 @using Phantom.Server.Services.Audit
 @using Phantom.Server.Services.Instances

Server/Phantom.Server/Phantom.Server.csproj

@@ -14,10 +14,10 @@
   <ItemGroup>
     <ProjectReference Include="..\..\Common\Phantom.Common.Data\Phantom.Common.Data.csproj" />
     <ProjectReference Include="..\..\Common\Phantom.Common.Logging\Phantom.Common.Logging.csproj" />
-    <ProjectReference Include="..\..\Common\Phantom.Common.Minecraft\Phantom.Common.Minecraft.csproj" />
     <ProjectReference Include="..\..\Utils\Phantom.Utils.IO\Phantom.Utils.IO.csproj" />
     <ProjectReference Include="..\..\Utils\Phantom.Utils.Runtime\Phantom.Utils.Runtime.csproj" />
     <ProjectReference Include="..\Phantom.Server.Database.Postgres\Phantom.Server.Database.Postgres.csproj" />
+    <ProjectReference Include="..\Phantom.Server.Minecraft\Phantom.Server.Minecraft.csproj" />
     <ProjectReference Include="..\Phantom.Server.Rpc\Phantom.Server.Rpc.csproj" />
     <ProjectReference Include="..\Phantom.Server.Services\Phantom.Server.Services.csproj" />
     <ProjectReference Include="..\Phantom.Server.Web\Phantom.Server.Web.csproj" />

Server/Phantom.Server/WebConfigurator.cs

@@ -1,6 +1,6 @@
 using Microsoft.Extensions.DependencyInjection;
 using Phantom.Common.Data.Agent;
-using Phantom.Common.Minecraft;
+using Phantom.Server.Minecraft;
 using Phantom.Server.Services;
 using Phantom.Server.Services.Agents;
 using Phantom.Server.Services.Audit;