feat(observability): add diagnostic dashboards (#27)

2026-07-17 00:22:46 +02:00
parent 06c4ecf8f3
commit 99885f8c8c
30 changed files with 3173 additions and 18 deletions
@@ -0,0 +1,111 @@
+using System.Reflection;
+using FinalFactory.Rendezvous.Contracts;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Options;
+
+namespace FinalFactory.Rendezvous.Server.Diagnostics;
+
+internal static class DiagnosticDashboardEndpoints
+{
+    private const string ContentSecurityPolicy =
+        "default-src 'none'; base-uri 'none'; connect-src 'self'; "
+        + "font-src 'self'; form-action 'none'; frame-ancestors 'none'; "
+        + "img-src 'self'; manifest-src 'none'; object-src 'none'; "
+        + "script-src 'self'; style-src 'self'";
+    private static readonly byte[] Index = ReadAsset("index.html");
+    private static readonly byte[] Script = ReadAsset("app.mjs");
+    private static readonly byte[] Styles = ReadAsset("styles.css");
+
+    public static IEndpointRouteBuilder MapDiagnosticDashboardEndpoints(
+        this IEndpointRouteBuilder endpoints)
+    {
+        RouteGroupBuilder dashboard = endpoints.MapGroup("/diagnostics")
+            .ExcludeFromDescription();
+        dashboard.MapGet("", ServeIndex);
+        dashboard.MapGet("/app.mjs", ServeScript);
+        dashboard.MapGet("/styles.css", ServeStyles);
+        dashboard.MapGet("/config.json", ServeConfiguration);
+        return endpoints;
+    }
+
+    private static IResult ServeIndex(
+        HttpContext context,
+        [FromServices] IOptions<DiagnosticDashboardOptions> configured) =>
+        ServeAsset(context, configured.Value, Index, "text/html; charset=utf-8");
+
+    private static IResult ServeScript(
+        HttpContext context,
+        [FromServices] IOptions<DiagnosticDashboardOptions> configured) =>
+        ServeAsset(context, configured.Value, Script, "text/javascript; charset=utf-8");
+
+    private static IResult ServeStyles(
+        HttpContext context,
+        [FromServices] IOptions<DiagnosticDashboardOptions> configured) =>
+        ServeAsset(context, configured.Value, Styles, "text/css; charset=utf-8");
+
+    private static IResult ServeConfiguration(
+        HttpContext context,
+        [FromServices] IOptions<DiagnosticDashboardOptions> configured)
+    {
+        DiagnosticDashboardOptions options = configured.Value;
+        if (!options.Enabled)
+        {
+            return Results.NotFound();
+        }
+
+        ApplySecurityHeaders(context.Response);
+        return Results.Json(new
+        {
+            contractVersion = ContractLimits.ContractVersion,
+            pollIntervalSeconds = options.PollIntervalSeconds,
+            maximumRenderedSessions = options.MaximumRenderedSessions,
+            scopes = options.Scopes.Select(static scope => new
+            {
+                gameId = scope.GameId,
+                environmentId = scope.EnvironmentId,
+                protocolVersions = scope.ProtocolVersions,
+                regions = scope.Regions,
+                visibility = "public",
+            }),
+        });
+    }
+
+    private static IResult ServeAsset(
+        HttpContext context,
+        DiagnosticDashboardOptions options,
+        byte[] content,
+        string contentType)
+    {
+        if (!options.Enabled)
+        {
+            return Results.NotFound();
+        }
+
+        ApplySecurityHeaders(context.Response);
+        return Results.Bytes(content, contentType);
+    }
+
+    private static void ApplySecurityHeaders(HttpResponse response)
+    {
+        response.Headers.CacheControl = "no-store";
+        response.Headers["Content-Security-Policy"] = ContentSecurityPolicy;
+        response.Headers["X-Content-Type-Options"] = "nosniff";
+        response.Headers["X-Frame-Options"] = "DENY";
+        response.Headers["Cross-Origin-Opener-Policy"] = "same-origin";
+        response.Headers["Cross-Origin-Resource-Policy"] = "same-origin";
+        response.Headers["Permissions-Policy"] =
+            "camera=(), geolocation=(), microphone=(), payment=(), usb=()";
+        response.Headers["Referrer-Policy"] = "no-referrer";
+    }
+
+    private static byte[] ReadAsset(string fileName)
+    {
+        Assembly assembly = typeof(DiagnosticDashboardEndpoints).Assembly;
+        string resourceName = $"FinalFactory.Rendezvous.Server.Diagnostics.Assets.{fileName}";
+        using Stream source = assembly.GetManifestResourceStream(resourceName)
+            ?? throw new InvalidOperationException($"Missing embedded dashboard asset {fileName}.");
+        using MemoryStream destination = new();
+        source.CopyTo(destination);
+        return destination.ToArray();
+    }
+}