allow servers to read appsettings from different location

MareSynchronosServer/MareSynchronosAuthService/.config/dotnet-tools.json

@@ -0,0 +1,13 @@
+{
+  "version": 1,
+  "isRoot": true,
+  "tools": {
+    "dotnet-ef": {
+      "version": "8.0.10",
+      "commands": [
+        "dotnet-ef"
+      ],
+      "rollForward": false
+    }
+  }
+}

MareSynchronosServer/MareSynchronosAuthService/Program.cs

@@ -27,6 +27,20 @@ public class Program
         return Host.CreateDefaultBuilder(args)
             .UseSystemd()
             .UseConsoleLifetime()
+            .ConfigureAppConfiguration((ctx, config) =>
+            {
+                var appSettingsPath = Environment.GetEnvironmentVariable("APPSETTINGS_PATH");
+                if (!string.IsNullOrEmpty(appSettingsPath))
+                {
+                    config.AddJsonFile(appSettingsPath, optional: true, reloadOnChange: true);
+                }
+                else
+                {
+                    config.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true);
+                }
+
+                config.AddEnvironmentVariables();
+            })
             .ConfigureWebHostDefaults(webBuilder =>
             {
                 webBuilder.UseContentRoot(AppContext.BaseDirectory);