PlatformIdentifier now performs compatibility checks

src/Tgstation.Server.Host/System/IPlatformIdentifier.cs

@@ -14,5 +14,10 @@
 		/// The extension of executable script files for the system
 		/// </summary>
 		string ScriptFileExtension { get; }
+
+		/// <summary>
+		/// Check if the system is capable of running tgstation-server.
+		/// </summary>
+		void CheckCompatibility();
 	}
 }

src/Tgstation.Server.Host/System/PlatformIdentifier.cs

@@ -1,4 +1,8 @@
-using System.Runtime.InteropServices;
+using LibGit2Sharp;
+using Microsoft.Extensions.Logging;
+using System;
+using System.Runtime.InteropServices;
+using Tgstation.Server.Host.Security;
 
 namespace Tgstation.Server.Host.System
 {
@@ -11,13 +15,46 @@ namespace Tgstation.Server.Host.System
 		/// <inheritdoc />
 		public string ScriptFileExtension { get; }
 
+		/// <summary>
+		/// The <see cref="ISystemIdentityFactory"/> for the <see cref="PlatformIdentifier"/>.
+		/// </summary>
+		readonly ISystemIdentityFactory systemIdentityFactory;
+
+		/// <summary>
+		/// The <see cref="ILogger"/> for the <see cref="PlatformIdentifier"/>.
+		/// </summary>
+		readonly ILogger<PlatformIdentifier> logger;
+
 		/// <summary>
 		/// Construct a <see cref="PlatformIdentifier"/>
 		/// </summary>
-		public PlatformIdentifier()
+		/// <param name="systemIdentityFactory">The value of <see cref="ISystemIdentityFactory"/>.</param>
+		/// <param name="logger">The value of <see cref="logger"/>.</param>
+		public PlatformIdentifier(ISystemIdentityFactory systemIdentityFactory, ILogger<PlatformIdentifier> logger)
 		{
+			this.systemIdentityFactory = systemIdentityFactory ?? throw new ArgumentNullException(nameof(systemIdentityFactory));
+			this.logger = logger ?? throw new ArgumentNullException(nameof(logger));
+
 			IsWindows = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
 			ScriptFileExtension = IsWindows ? "bat" : "sh";
 		}
+
+		/// <inheritdoc />
+		public void CheckCompatibility()
+		{
+			try
+			{
+				new Repository().Dispose();
+			}
+			catch
+			{
+				logger.LogCritical("Unable to initialize libgit2! This is a common problem on POSIX installations. Try using Docker.");
+				throw;
+			}
+
+			using var systemIdentity = systemIdentityFactory.GetCurrent();
+			if (!systemIdentity.CanCreateSymlinks)
+				throw new InvalidOperationException("The user running tgstation-server cannot create symlinks! Please try running as an administrative user!");
+		}
 	}
 }