Fix mesh-forwarded image requests losing body data

CodeProject.AI.sln

@@ -1,5 +1,4 @@
-
-Microsoft Visual Studio Solution File, Format Version 12.00
+Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.2.32616.157
 MinimumVisualStudioVersion = 10.0.40219.1

src/server/Controllers/ProxyController.cs

@@ -15,6 +15,7 @@
 
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 
 using CodeProject.AI.SDK.API;
@@ -65,6 +66,7 @@ public class ProxyController : ControllerBase
         private readonly TriggerTaskRunner _commandRunner;
         private readonly MeshManager _meshManager;
         private readonly ModuleProcessServices _moduleProcessService;
+        private readonly ILogger<ProxyController> _logger;
 
         private bool   _verbose = false;
 
@@ -79,13 +81,15 @@ public class ProxyController : ControllerBase
         /// <param name="commandRunner">The command runner</param>
         /// <param name="meshManager">The mesh manager</param>
         /// <param name="moduleProcessService">The module process service</param>
+        /// <param name="logger">The logger</param>
         public ProxyController(CommandDispatcher dispatcher,
                                BackendRouteMap routeMap,
                                IOptions<ModuleCollection> ModuleCollectionOptions,
                                IOptions<TriggersConfig> triggersConfig,
                                TriggerTaskRunner commandRunner,
                                MeshManager meshManager,
-                               ModuleProcessServices moduleProcessService)
+                               ModuleProcessServices moduleProcessService,
+                               ILogger<ProxyController> logger)
         {
             _dispatcher           = dispatcher;
             _routeMap             = routeMap;
@@ -94,6 +98,7 @@ public ProxyController(CommandDispatcher dispatcher,
             _commandRunner        = commandRunner;
             _meshManager          = meshManager;
             _moduleProcessService = moduleProcessService;
+            _logger               = logger;
         }
 
         /// <summary>
@@ -386,11 +391,10 @@ public IActionResult ApiSummary()
             }
             catch (Exception ex)
             {
-                Debug.WriteLine($"Error in DispatchRemoteRequest ({server.Status.Hostname}): {ex}");
+                _logger.LogError(ex, "Error in DispatchRemoteRequest ({Hostname})", server.Status.Hostname);
 
-                // Bump the response to 30s to push this server out of contention. Maybe also add
-                // exception info to the message
-                error      = $"Exception when forwarding request to {server.Status.Hostname}";                
+                // Bump the response to 30s to push this server out of contention.
+                error      = $"Exception when forwarding request to {server.Status.Hostname}: {ex.Message}";
                 elapsedMs  = 30_000;
             }
             finally
@@ -521,6 +525,13 @@ public IActionResult ApiSummary()
         private async Task<HttpResponseMessage> ForwardAsync(MeshServerRoutingEntry server)
         {
             HttpRequest originalRequest = Request;
+
+            // The body may already have been read once by ASP.NET Core's own model-binding
+            // pipeline before this point. EnableBuffering() (see Startup.cs) makes the body
+            // seekable so we can safely rewind it here and forward the full original content.
+            if (originalRequest.Body.CanSeek)
+                originalRequest.Body.Position = 0;
+
             int? port         = originalRequest.Host.Port;
             string portString = port.HasValue ? $":{port}" : string.Empty;
             var queryString   = originalRequest.QueryString;
@@ -538,7 +549,10 @@ private async Task<HttpResponseMessage> ForwardAsync(MeshServerRoutingEntry serv
             };
 
             foreach (KeyValuePair<string, Microsoft.Extensions.Primitives.StringValues> header in originalRequest.Headers)
-                newRequest.Headers.TryAddWithoutValidation(header.Key, header.Value.AsEnumerable());
+            {
+                if (!newRequest.Headers.TryAddWithoutValidation(header.Key, header.Value.AsEnumerable()))
+                    newRequest.Content!.Headers.TryAddWithoutValidation(header.Key, header.Value.AsEnumerable());
+            }
 
             newRequest.Headers.Add(CPAI_Forwarded_Header, "true");
 

src/server/Mesh/MeshSummary.cs

@@ -36,7 +36,7 @@ public string Summary
                 }
                 summary.AppendLine($"{indent}Active:              {IsActive}");
                 summary.AppendLine($"{indent}Forwarding Requests: {Status.AllowRequestForwarding}");
-                summary.AppendLine($"{indent}Accepting Requests:  {Status.AllowRequestForwarding}");
+                summary.AppendLine($"{indent}Accepting Requests:  {Status.AcceptForwardedRequests}");
 
                 if (Status.KnownHostnames is not null)
                 {

src/server/Startup.cs

@@ -11,6 +11,7 @@
 
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
@@ -137,6 +138,16 @@ public void Configure(IApplicationBuilder app,
             _versionConfig = versionConfig.Value;
             _logger        = logger;
 
+            // Enable request body buffering globally, as early as possible, so any code
+            // downstream (in particular ProxyController's mesh-forwarding logic) can safely
+            // re-read/replay the request body even after ASP.NET Core's own model-binding
+            // infrastructure has already read from it once.
+            app.Use(async (context, next) =>
+            {
+                context.Request.EnableBuffering();
+                await next();
+            });
+
             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();

src/server/wwwroot/assets/dashboard.js

@@ -546,7 +546,7 @@ function meshServerSummary(server, isLocal) {
         summary += `${indent}All Addresses:       ${server.allIPAddresses.join(", ")}\n`;
     summary += `${indent}Active:              ${activeStr(server.isActive)}\n`;
     summary += `${indent}Forwarding Requests: ${activeStr(server.status.allowRequestForwarding)}\n`;
-    summary += `${indent}Accepting Requests:  ${activeStr(server.status.allowRequestForwarding)}\n`;
+    summary += `${indent}Accepting Requests:  ${activeStr(server.status.acceptForwardedRequests)}\n`;
 
     // Routes (may be an empty list)
     let hideRoutes = document.getElementById("showMeshRoutes") &&