Original address: https://www.cnblogs.com/duanweishi/p/9286461.html

explain

Because there are multiple items on the personal server and the secondary domain name is configured, the secondary domain name needs to be forwarded. In the forwarding work, the famous nginx is adopted. Before that, there was no problem in forwarding all projects. However, when deploying a project with websocket communication, an unexpected error was reported. The error message is as follows:

1failed: Error during WebSocket handshake: Unexpected response code: 400

。 There is no problem with this error in the local test environment and accessing non nginx forwarding. Therefore, it is inferred that the problem should occur in nginx forwarding.

So, with the help of Google , I saw socket. IO   The official issues has a discussion on this issue, link: https://github.com/socketio/socket.io/issues/1942

Solution

After reading the scheme in the discussion area, the problem appears in the configuration file of nginx , and the nginx.conf file needs to be modified. In the linux terminal, type VIM/etc/nginx/nginx.conf , find the location , and the configuration file is as follows:

1server {
2        listen       80;
3        server_name  school.godotdotdot.com;
4        charset utf-8;
5
6        location/{
7            proxy_pass http://127.0.0.1:3000;
8            proxy_set_header Host $host;
9            proxy_http_version 1.1; 
10            proxy_set_header Upgrade $http_upgrade;
11            proxy_set_header Connection "upgrade";
12            proxy_set_header X-Real-IP $remote_addr;
13            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
14            proxy_connect_timeout 60;
15            proxy_read_timeout 600;
16            proxy_send_timeout 600;
17        }
18
19        error_page   500 502 503 504  /50x.html;
20        location = /50x.html {
21            root   html;
22        }
23
24    }

The most important of these are the following three lines

1proxy_http_version 1.1;
2proxy_set_header Upgrade $http_upgrade;
3proxy_set_header Connection "upgrade";

The first line tells nginx to use the http/1.1 communication protocol, which must be used by websoket .

The second and third lines tell nginx to respond to the HTTP upgrade request when it wants to use websocket.