🔧 Improve health check logic in Gitea workflows

- Enhanced health check mechanisms in `ci-cd-fast.yml` and `ci-cd-zero-downtime-fixed.yml` to utilize `docker exec` for internal checks, addressing issues with direct port access.
- Updated health check logic to provide better error messages and fallback methods, ensuring more reliable deployment verification.
- Documented changes in `DEPLOYMENT-FIXES.md` to reflect improvements in health check processes.

✅ These updates enhance the reliability of health checks during deployments and improve debugging capabilities.

.gitea/workflows/ci-cd-zero-downtime-fixed.yml

@@ -160,10 +160,10 @@ EOF
           echo "📊 Checking container status..."
           docker compose -f docker-compose.zero-downtime-fixed.yml ps
           
-          # Wait for application containers to be healthy
+          # Wait for application containers to be healthy (internal check)
           echo "🏥 Waiting for application containers to be healthy..."
           for i in {1..30}; do
-            # Check if both app containers are healthy
+            # Check if both app containers are healthy internally
             if docker exec portfolio-app-1 curl -f http://localhost:3000/api/health > /dev/null 2>&1 && \
                docker exec portfolio-app-2 curl -f http://localhost:3000/api/health > /dev/null 2>&1; then
               echo "✅ Both application containers are healthy!"
@@ -173,15 +173,20 @@ EOF
             sleep 3
           done
           
-          # Wait for nginx to be healthy
-          echo "🌐 Waiting for nginx to be healthy..."
-          for i in {1..20}; do
+          # Wait for nginx to be healthy and proxy to work
+          echo "🌐 Waiting for nginx to be healthy and proxy to work..."
+          for i in {1..30}; do
+            # Check nginx health endpoint
             if curl -f http://localhost/health > /dev/null 2>&1; then
-              echo "✅ Nginx is healthy!"
-              break
+              echo "✅ Nginx health endpoint is working!"
+              # Now check if nginx can proxy to the application
+              if curl -f http://localhost/api/health > /dev/null 2>&1; then
+                echo "✅ Nginx proxy to application is working!"
+                break
+              fi
             fi
-            echo "⏳ Waiting for nginx... ($i/20)"
-            sleep 2
+            echo "⏳ Waiting for nginx and proxy... ($i/30)"
+            sleep 3
           done
 
       - name: Health check
@@ -192,7 +197,7 @@ EOF
           echo "📊 Container status:"
           docker compose -f docker-compose.zero-downtime-fixed.yml ps
           
-          # Check individual application containers
+          # Check individual application containers (internal)
           echo "🏥 Checking individual application containers..."
           if docker exec portfolio-app-1 curl -f http://localhost:3000/api/health; then
             echo "✅ portfolio-app-1 health check passed!"
@@ -219,11 +224,13 @@ EOF
             exit 1
           fi
           
-          # Check application health through nginx
+          # Check application health through nginx (this is the main test)
           if curl -f http://localhost/api/health; then
             echo "✅ Application health check through nginx passed!"
           else
             echo "❌ Application health check through nginx failed!"
+            echo "Nginx logs:"
+            docker logs portfolio-nginx --tail=20
             exit 1
           fi