nginx 反向代理 websocket

在服务器上配置 docker + jupyter notebook 的时候遇到一个问题：

jupyter lab 页面中的实时通信是通过 websocket 与后端进行通信的，默认只配置 proxy_pass 会出现代码执行不了的情况。

需要在 nginx 中对 websocket 请求进行代理：

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

upstream jupyter {
  server localhost:8888;
}

server {
  listen 80;
  server_name jupyter.kgsoft.cn;

  location / {
    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_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;
    proxy_read_timeout 300s;
    proxy_pass http://jupyter;
  }
}