Issue with configuring nginx with websocket

[anilsathyan7]

After referring to the following links for setting nginx, I was unable to access the app. It shows the loading icon but does not show the UI elements.

• https://pywebio.readthedocs.io/en/latest/misc.html#nginx-websocket-config-example
• Error after configuring nginx #68 (comment)

The application is not being loaded due to websocket connection failure.

ERROR: Firefox can’t establish a connection to the server at wss://address.com/app-manager/tool?app=index&session=NEW

Nginx config(etc/nginx/sites-enabled/default):-

map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
    }

server {
        listen 80 default_server;
        listen [::]:80 default_server;

      
        root /var/www/html;

        # Add index.php to the list if you are using PHP
        index index.html index.htm index.nginx-debian.html;

        server_name _;

        location / {
                # First attempt to serve request as file, then
                # as directory, then fall back to displaying a 404.
                try_files $uri $uri/ =404;
        }


        location /app-manager {
            alias /home/user/autoweb/lib/python3.7/site-packages/pywebio/html;
        }

        location /app-manager/tool {
             proxy_read_timeout 300s;
             proxy_send_timeout 300s;
             proxy_http_version 1.1;
             proxy_set_header Host $host:$server_port;
             proxy_set_header Upgrade $http_upgrade;
             proxy_set_header Connection $connection_upgrade;
             proxy_pass http://localhost:2021/;
        }

I'am able to run it as localhost without nginx but otherwise it fails.

Logs:-
Localhost - tornado.access - web.py:2243 - INFO - 101 GET /?app=index&session=NEW (127.0.0.1) [worked]
Server - tornado.access - web.py:2243 - INFO - 200 GET /?app=index&session=NEW [failed]

[wang0618]

Try add allowed_origins=['*'] to start_server() ? Just like pywebio.start_server(main, port= 2021, debug=True, allowed_origins=['*'])

[anilsathyan7]

The difference between localhost and remote server is as follows:-

ws://localhost/app-manager/tool?app=index&session=NEW [HTTP/1.1 101 Switching Protocols 1ms] - Works
wss://address.com/app-manager/tool?app=index&session=NEW [HTTP/1.1 200 OK 93ms] - Fails

Error is: Firefox can’t establish a connection to the server at wss://address.com/app-manager/tool?app=index&session=NEW.
There are no other logs from application even if I enable debug -pywebio.enable_debug() or start_server(debug=True)

The issue seems to be related to SSL/security ...

[anilsathyan7]

do we need to add ssl_certificate /path/to/crt; ssl_certificate_key /path/to/key; for https?

[anilsathyan7]

There were multiple proxies, so i had to add the websocket config in parent proxy with ssl to resolve the issue.

[fuxin123z]

allowed_origins=['*']

[Lihao2017-11-15]

my config file in /etc/nginx/sites-enabled/diancan

upstream diancan{
server 127.0.0.1:8080;
}

map $http_upgrade $connection_upgrade {
default upgrade;
'' close;
}

server {
listen 80;
server_name 192.168.30.7;

location / {
     proxy_read_timeout 30s;
     proxy_send_timeout 30s;
     proxy_http_version 1.1;
     proxy_set_header Host $http_host;
     proxy_set_header Upgrade $http_upgrade;
     proxy_set_header Connection $connection_upgrade;
     proxy_pass http://diancan;
}

}