Error 502 (Bad Gateway) "_stcore/" streamlit in AWS using nginx

Deployment
, ,
1

Hello anyone can help me in my streamlit in AWS using nginx, the website is displaying but I’m getting this error when running my code. Thank you

image

nginx.conf:

server {
        listen       80;
        listen       [::]:80;
        server_name  _;

        client_max_body_size 20M;

        location / {
        proxy_pass      http://localhost:8501;
        }

        location ^~ /_stcore/static {
            proxy_pass http://localhost:8501/static;
            proxy_http_version 1.1;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header Host $host;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            proxy_set_header Sec-WebSocket-Extensions $http_sec_websocket_extentions;
            proxy_read_timeout 85400;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-Proto $scheme;
        }

        location ^~ /_stcore/healthz {
            proxy_pass http://localhost:8501/_stcore/healthz;
        }

        location ^~ /_stcore/vendor {
            proxy_pass http://localhost:8501/_stcore/vendor;
        }

        location /_stcore/stream {
            proxy_pass http://localhost:8501/_stcore/stream;
            proxy_http_version 1.1;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header Host $host;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            proxy_set_header Sec-WebSocket-Extensions $http_sec_websocket_extentions;
            proxy_read_timeout 85400;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-Proto $scheme;
        }

        root         /usr/share/nginx/html;

        include /etc/nginx/default.d/*.conf;

        error_page 404 /404.html;
        location = /404.html {
        }

        error_page 500 502 503 504 /50x.html;
        location = /50x.html {
        }
    }
2

Did you figure out a solution?

3

I looks like there was a similar thread in the past and @Caroline linked a working solution here.

I don’t think we have changed paths since then, so it should hopefully still work.

4

Hi, thanks for your reply, but unfortunaly, It still does not work. It still prints a lot of messages like this

nginx          | 192.168.120.253 - - [08/Sep/2024:06:07:58 +0000] "GET /_stcore/stream HTTP/1.1" 400 34 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36" "174.73.145.75"

Here is the config of nginx that I copied and pasted

server {
    server_name website.com;

    location / {
                proxy_pass http://streamlit_app: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;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection "upgrade";
    }

        location /_stcore/stream {
                proxy_pass http://streamlit_app:8501/_stcore/stream;
                proxy_http_version 1.1;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header Host $host;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection "upgrade";
                proxy_read_timeout 86400;
        }

}
5

Hey @Chuong , sorry to hear that it still does not work! Without knowing the specifics of your deployment environment, it is pretty difficult to debug and support this.
If I were you, I would probably add a simple, static route to nginx like

location /hello {
  default_type text/plain;
  echo "hello, world!";
}

and see whether you can hit that endpoint successfully to figure out at which level the issue happens.

6

hey @raethlein i used same config as shown in the above shared solution. and added this line to the config

       location /hello {
                root /var/www/html;
                try_files /hello.html =404;
       }

and its working fine and rendering the html page.
but the main app is showing the skeleton ui , with nginx access log as :
“GET /_stcore/stream HTTP/1.1” 400 34 “-” “Mozilla/5.0 …”.