Replace Python proxy with Nginx to support Streamlit WebSockets and fix blank screen

Dockerfile

@@ -4,11 +4,15 @@ FROM python:3.12-slim
 RUN apt-get update && apt-get install -y \
     gcc g++ \
     redis-server \
+    nginx \
     && rm -rf /var/lib/apt/lists/*
 
+# Setup Nginx for non-root user
+RUN mkdir -p /var/lib/nginx /var/log/nginx /run/nginx && \
+    chown -R 1000:1000 /var/lib/nginx /var/log/nginx /run/nginx
+
 # 🚀 CRITICAL FOR HUGGING FACE SPACES 🚀
 # HF Spaces run as a non-root user (uid 1000)
-# We must create this user and set the home directory
 RUN useradd -m -u 1000 user
 USER user
 ENV HOME=/home/user \

backend/main.py

@@ -9,9 +9,6 @@ from fastapi.responses import FileResponse
 from fastapi.staticfiles import StaticFiles
 from contextlib import asynccontextmanager
 from infra.logger import get_logger
-import httpx
-from fastapi import Request
-from fastapi.responses import StreamingResponse
 
 log = get_logger(__name__)
 csv.field_size_limit(int(1e9))
@@ -115,42 +112,7 @@ def health_check():
     return {"status": "ok", "version": "4.0.0"}
 
 
-# ── Streamlit Reverse Proxy ──────────────────────────────────────────────────
-# This catch-all route forwards any non-API requests to the Streamlit port (8001).
-STREAMLIT_URL = "http://localhost:8001"
-
-@app.api_route("/{path_name:path}", include_in_schema=False)
-async def _proxy_to_streamlit(request: Request, path_name: str):
-    # Skip if the path is explicitly an API route (though FastAPI should have caught it)
-    if path_name.startswith("api/") or path_name.startswith("docs") or path_name.startswith("redoc") or path_name.startswith("openapi.json"):
-        return {"error": "Not Found"}
-
-    target_url = f"{STREAMLIT_URL}/{path_name}"
-    if request.query_params:
-        target_url += f"?{request.query_params}"
-
-    async with httpx.AsyncClient() as client:
-        # Standard proxy logic
-        method = request.method
-        headers = dict(request.headers)
-        # We must remove host and adjust for the internal service
-        headers.pop("host", None)
-        
-        # Handle Streamlit's specific requirements (like websockets if needed, but simple HTTP first)
-        response = await client.request(
-            method,
-            target_url,
-            content=await request.body(),
-            headers=headers,
-            timeout=60.0,
-            follow_redirects=True,
-        )
-
-        return StreamingResponse(
-            response.aiter_bytes(),
-            status_code=response.status_code,
-            headers=dict(response.headers),
-        )
+
 
 
 if __name__ == "__main__":

frontend/pages/1_Home.py

@@ -9,7 +9,7 @@ from ui_shell import (
     render_workspace_banner,
 )
 
-API_URL = "http://localhost:7860/api"
+API_URL = "http://localhost:8000/api"
 
 st.set_page_config(page_title="Home - AutoML Studio", page_icon="🏠", layout="wide")
 

frontend/pages/2_Dataset_DNA.py

@@ -10,7 +10,7 @@ from ui_shell import (
     render_workspace_banner,
 )
 
-API_URL = "http://localhost:7860/api"
+API_URL = "http://localhost:8000/api"
 
 st.set_page_config(page_title="Dataset DNA", page_icon="🧬", layout="wide")
 

frontend/pages/3_Training_Lab.py

@@ -10,7 +10,7 @@ from ui_shell import (
     render_workspace_banner,
 )
 
-API_URL = "http://localhost:7860/api"
+API_URL = "http://localhost:8000/api"
 
 st.set_page_config(page_title="Live Training & Results", page_icon="⚡", layout="wide")
 

frontend/pages/4_Results_Console.py

@@ -14,7 +14,7 @@ from ui_shell import (
     render_workspace_banner,
 )
 
-API_URL = "http://localhost:7860/api"
+API_URL = "http://localhost:8000/api"
 
 st.set_page_config(page_title="Results Console - AutoML Studio", page_icon="📊", layout="wide")
 

frontend/pages/5_Experiment_Tracker.py

@@ -9,7 +9,7 @@ from ui_shell import (
     render_workspace_banner,
 )
 
-API_URL = "http://localhost:7860/api"
+API_URL = "http://localhost:8000/api"
 
 
 def api_json(path: str, timeout: int = 10):

frontend/pages/6_Drift_Monitor.py

@@ -9,7 +9,7 @@ from ui_shell import (
     render_workspace_banner,
 )
 
-API_URL = "http://localhost:7860/api"
+API_URL = "http://localhost:8000/api"
 
 st.set_page_config(page_title="Drift Monitor", page_icon="📉", layout="wide")
 

frontend/pages/7_Smart_AI_Hub.py

@@ -10,7 +10,7 @@ from ui_shell import (
     render_workspace_banner,
 )
 
-API_URL = "http://localhost:7860/api"
+API_URL = "http://localhost:8000/api"
 
 st.set_page_config(page_title="Smart AI Hub - AutoML Studio", page_icon="🤖", layout="wide")
 

frontend/ui_shell.py

@@ -4,7 +4,7 @@ from typing import Iterable, Optional
 import requests
 import streamlit as st
 
-API_URL = "http://localhost:7860/api"
+API_URL = "http://localhost:8000/api"
 
 SESSION_DEFAULTS = {
     "dataset_id": None,

nginx.conf

@@ -0,0 +1,75 @@
+worker_processes 1;
+daemon off;
+pid /tmp/nginx.pid;
+
+events {
+    worker_connections 1024;
+}
+
+http {
+    include /etc/nginx/mime.types;
+    default_type application/octet-stream;
+    
+    access_log /tmp/nginx_access.log;
+    error_log /tmp/nginx_error.log;
+    
+    client_body_temp_path /tmp/nginx_client_body;
+    proxy_temp_path /tmp/nginx_proxy;
+    fastcgi_temp_path /tmp/nginx_fastcgi;
+    uwsgi_temp_path /tmp/nginx_uwsgi;
+    scgi_temp_path /tmp/nginx_scgi;
+
+    sendfile on;
+    keepalive_timeout 65;
+
+    # Gzip settings
+    gzip on;
+    gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
+
+    server {
+        listen 7860;
+        server_name localhost;
+
+        # ── FastAPI Backend (API & Docs) ────────────────────────
+        location ~ ^/(api|docs|redoc|openapi.json) {
+            proxy_pass http://localhost:8000;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+            proxy_set_header X-Forwarded-Proto $scheme;
+            
+            # Increase timeouts for long-running training jobs
+            proxy_read_timeout 600s;
+            proxy_connect_timeout 600s;
+        }
+
+        # ── Streamlit Websocket (/stream) ───────────────────────
+        location /stream {
+            proxy_pass http://localhost:8501/stream;
+            proxy_http_version 1.1;
+            proxy_set_header Upgrade $http_upgrade;
+            proxy_set_header Connection "upgrade";
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+            proxy_set_header X-Forwarded-Proto $scheme;
+            proxy_read_timeout 86400;
+        }
+
+        # ── Streamlit Static & UI ───────────────────────────────
+        location / {
+            proxy_pass http://localhost:8501;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+            proxy_set_header X-Forwarded-Proto $scheme;
+            
+            # Static file caching
+            location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
+                proxy_pass http://localhost:8501;
+                expires 1y;
+                add_header Cache-Control "public, no-transform";
+            }
+        }
+    }
+}

start.sh

@@ -10,15 +10,14 @@ export PYTHONPATH="$SCRIPT_DIR/backend:$PYTHONPATH"
 export HOME="/home/user"
 
 # 1. Start Redis (Internal Broker)
-# We run it in the background using & and point it to /tmp for write access.
 echo "Starting Redis..."
 redis-server --port 6379 --dir /tmp --dbfilename dump.rdb --daemonize no &
 REDIS_PID=$!
 
-# 2. Start FastAPI Backend (Public Gateway)
-echo "Starting FastAPI Backend on port ${PORT:-7860}..."
+# 2. Start FastAPI Backend (Internal API)
+echo "Starting FastAPI Backend on port 8000..."
 cd "$SCRIPT_DIR/backend"
-python -m uvicorn main:app --host 0.0.0.0 --port "${PORT:-7860}" --timeout-keep-alive 600 &
+python -m uvicorn main:app --host 127.0.0.1 --port 8000 --timeout-keep-alive 600 &
 BACKEND_PID=$!
 
 # 3. Start Celery Worker (Task Processor)
@@ -27,14 +26,19 @@ cd "$SCRIPT_DIR/backend"
 python -m celery -A core.worker.celery_app worker --loglevel=info --concurrency=1 &
 WORKER_PID=$!
 
-# 4. Start Streamlit Frontend (Internal Service)
-# This port (8001) will be proxied by FastAPI.
-echo "Starting Streamlit Frontend on internal port 8001..."
+# 4. Start Streamlit Frontend (Internal UI)
+echo "Starting Streamlit Frontend on port 8501..."
 cd "$SCRIPT_DIR/frontend"
-python -m streamlit run app.py --server.port 8001 --server.headless true --server.address 127.0.0.1 &
+python -m streamlit run app.py --server.port 8501 --server.headless true --server.address 127.0.0.1 &
 FRONTEND_PID=$!
 
+# 5. Start Nginx (Public Gateway)
+echo "Starting Nginx on port ${PORT:-7860}..."
+# We use -c to point to our custom config
+nginx -c "$SCRIPT_DIR/nginx.conf" &
+NGINX_PID=$!
+
 echo "🚀 All services launched!"
 
-# Keep the script alive. If the Frontend or Backend fails, the container should stop.
-wait -n $FRONTEND_PID $BACKEND_PID
+# Keep the script alive.
+wait -n $NGINX_PID $FRONTEND_PID $BACKEND_PID