Fix viewer proxy configuration for Hugging Face Spaces

Dockerfile

@@ -63,29 +63,49 @@ events {\n\
 }\n\
 http {\n\
     access_log /dev/stdout;\n\
+    client_max_body_size 0;\n\
+    \n\
     upstream nicegui {\n\
         server 127.0.0.1:7861;\n\
     }\n\
+    \n\
     upstream viewer {\n\
         server 127.0.0.1:3939;\n\
     }\n\
+    \n\
+    map $http_upgrade $connection_upgrade {\n\
+        default upgrade;\n\
+        "" close;\n\
+    }\n\
+    \n\
     server {\n\
         listen 7860;\n\
         server_name localhost;\n\
+        \n\
+        # Main app (NiceGUI)\n\
         location / {\n\
             proxy_pass http://nicegui;\n\
             proxy_http_version 1.1;\n\
             proxy_set_header Upgrade $http_upgrade;\n\
-            proxy_set_header Connection "upgrade";\n\
+            proxy_set_header Connection $connection_upgrade;\n\
             proxy_set_header Host $host;\n\
+            proxy_set_header X-Real-IP $remote_addr;\n\
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;\n\
+            proxy_set_header X-Forwarded-Proto $scheme;\n\
         }\n\
-        location /proxy/3939/viewer {\n\
-            proxy_pass http://viewer/viewer;\n\
+        \n\
+        # Viewer route\n\
+        location /viewer/ {\n\
+            proxy_pass http://viewer/viewer/;\n\
             proxy_http_version 1.1;\n\
             proxy_set_header Upgrade $http_upgrade;\n\
-            proxy_set_header Connection "upgrade";\n\
+            proxy_set_header Connection $connection_upgrade;\n\
             proxy_set_header Host $host;\n\
+            proxy_set_header X-Real-IP $remote_addr;\n\
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;\n\
+            proxy_set_header X-Forwarded-Proto $scheme;\n\
             proxy_read_timeout 86400;\n\
+            proxy_buffering off;\n\
         }\n\
     }\n\
 }' > /etc/nginx/nginx.conf && \

cadviewer.py

@@ -101,8 +101,8 @@ def check_viewer_ready():
     """Check if the viewer is ready by attempting a test connection"""
     try:
         import requests
-        # Check from inside the container using localhost
-        response = requests.get('http://localhost:3939/viewer')
+        # Check the viewer through Nginx proxy
+        response = requests.get('http://localhost:7860/viewer/')
         return response.status_code == 200
     except Exception as e:
         logger.error(f"Error checking viewer: {str(e)}")
@@ -199,7 +199,7 @@ with ui.splitter().classes(
             logger.info(f"Space URL: {space_url}")
             
             # Construct the viewer URL - use relative path for both local and Space environments
-            viewer_url = "/proxy/3939/viewer"
+            viewer_url = "/viewer/"  # Changed to match Nginx configuration
             logger.info(f"Using viewer URL: {viewer_url}")
             
             ocpcv = (