Nginx configuration proxy directive setting problem

Question

server {
    listen       80;

    server_name  mydomain.com;

    location /  {
        proxy_pass  http://myproxy.com:80;
        proxy_set_header Host    mydomain.com; #设置为跟server name 一样
    }
  

}

As above, when proxy_set_header is set to the same as the server name, a 502 error occurs.

The error stack is as follows:

upstream prematurely closed connection while reading response header from upstream, client: 127.0.0.1, server: mydomain.com, request: "GET /xx HTTP/1.0", upstream: "http://127.0.0.1:80/ xx", host: "mydomain.com

I am puzzled, what could be the reason for this?

---

When I update the proxy port, such as changing it from 80 to 81 proxy_pass http://myproxy.com:81;

At this point, it can work normally. (My previous myproxy.com was listen 80. Now it is changed to 81.)

But why ?

Answer 1

Your upstream is gone

Answer 2

CentOS7 installation and maintenance of Nginx, common usage scenarios

server {
  listen 80;
  server_name mydomain.com;
    
  location / {
    proxy_pass http://127.0.0.1:80;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host  $http_host;    
  } 
}

or this form

upstream server-a{
    # api 代理服务地址
    server 127.0.0.1:80;    
}
server {
    listen       80;
    server_name  mydomain.com;      # 这里指定域名
    # 匹配 api 路由的反向代理到API服务
    location ^~/ {
        rewrite ^/(.*)$ / break;
        proxy_pass http://server-a;
    }
}