Nginx 反向代理 WebSocket

設定 https://example.com:9999/socket.io
反向代理到 http://192.168.0.10:9999 的 WebSocket 服務

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

upstream websocket {
    server 192.168.0.10:9999;
}

server {
    listen 9999 ssl;
    server_name example.com;
    
    #ssl
    ssl_certificate /etc/nginx/ssl/example.com.crt;
    ssl_certificate_key /etc/nginx/ssl/example.com.key;

    location /socket.io {
        proxy_pass http://websocket;
        #Version 1.1 is recommended for use with keepalive connections
        proxy_http_version 1.1; #WebSocket
        proxy_set_header Upgrade $http_upgrade; #WebSocket
        proxy_set_header Connection $connection_upgrade; #WebSocket       
        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 https;
        proxy_set_header Cookie $http_cookie;
    }
    
    location = /favicon.ico {
        log_not_found off;
        access_log off;
    }
}

參考：

• https://www.nginx.com/blog/websocket-nginx/
  Using NGINX as a WebSocket Proxy
• https://single9.net/2018/03/nginx-reverse-proxy-server-and-socket-io/
  老闆！來一個能支援 Socket.io 的 NGINX Reverse Proxy Server 吧！ | Single.9
• https://kknews.cc/code/pn42zoj.html
  伺服器nginx下websocket nginx 配置心得分享
• https://github.com/REBELinBLUE/deployer/issues/310
  WebSocket connection handshake Error 502 · Issue #310 · REBELinBLUE/deployer · GitHub