Wait for backend to start before starting frontend.

Author: nzbdav-dev

Dockerfile

@@ -28,7 +28,7 @@ WORKDIR /app
 
 # Prepare environment
 RUN mkdir /config \
-    && apk add --no-cache nodejs npm libc6-compat shadow su-exec bash
+    && apk add --no-cache nodejs npm libc6-compat shadow su-exec bash curl
 
 # Copy frontend
 COPY --from=frontend-build /frontend/node_modules ./frontend/node_modules

backend/Extensions/NWebDavOptionsExtensions.cs

@@ -8,6 +8,7 @@ public static class NWebDavOptionsExtensions
     public static Func<HttpContext, bool> GetFilter(this NWebDavOptions options)
     {
         return context => !context.Request.Path.StartsWithSegments("/api") &&
-                          !context.Request.Path.StartsWithSegments("/view");
+                          !context.Request.Path.StartsWithSegments("/view") &&
+                          !context.Request.Path.StartsWithSegments("/health");
     }
 }

backend/Program.cs

@@ -51,6 +51,7 @@ static async Task Main(string[] args)
         var builder = WebApplication.CreateBuilder(args);
         builder.Host.UseSerilog();
         builder.Services.AddControllers();
+        builder.Services.AddHealthChecks();
         builder.Services
             .AddSingleton(configManager)
             .AddSingleton<UsenetStreamingClient>()
@@ -85,6 +86,7 @@ static async Task Main(string[] args)
 
         // run
         var app = builder.Build();
+        app.MapHealthChecks("/health");
         app.UseSerilogRequestLogging();
         app.UseMiddleware<ExceptionMiddleware>();
         app.UseAuthentication();

entrypoint.sh

@@ -54,6 +54,29 @@ cd /app/backend
 su-exec appuser ./NzbWebDAV &
 BACKEND_PID=$!
 
+# Wait for backend health check
+echo "Waiting for backend to start."
+MAX_RETRIES=30
+RETRY_DELAY=1
+i=0
+while true; do
+    echo "Checking backend health: $BACKEND_URL/health ..."
+    if curl -s -o /dev/null -w "%{http_code}" "$BACKEND_URL/health" | grep -q "^200$"; then
+        echo "Backend is healthy."
+        break
+    fi
+
+    i=$((i+1))
+    if [ "$i" -ge "$MAX_RETRIES" ]; then
+        echo "Backend failed health check after $MAX_RETRIES retries. Exiting."
+        kill $BACKEND_PID
+        wait $BACKEND_PID
+        exit 1
+    fi
+
+    sleep "$RETRY_DELAY"
+done
+
 # Run frontend as appuser in background
 cd /app/frontend
 su-exec appuser npm run start &