Docker starts nginx and cannot solve the proxy problem normally

Docker starts nginx and cannot proxy normally

Recently, I wanted to use nginx to proxy the second-level domain name to a different port, and found that an error would be reported

2023/04/12 08:18:28 [error] 24#24: *8 connect() failed (111: Connection refused) while connecting to upstream, client: 58.34.185.106, server: xxx.xxx.xxx, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:20077/", host: "xxx.xxx.xxx"

My configuration is very simple, which is to proxy to different ports through the domain name

server {
    
    
		listen       80;
		server_name  xxx.com;
		location / {
    
    
			proxy_pass http://127.0.0.1:20074;
		}
	}
server {
    
    
		listen      80;
		server_name  xxxx.com;
		location / {
    
    
			proxy_pass http://127.0.0.1:20077;
		}
	}

In fact, this is because the nginx started by docker is used. The nginx started by docker by default uses bridge模式the port mapping to the outside, and the access in the container localhostcannot access the host.

Docker network mode	configuration	illustrate
host mode	–net=host	The container and the host share the Network namespace
bridge mode	–net=bridge	The most commonly used mode (this mode is the default)
none mode	–net=none	The container has an independent Network namespace, but it does not make any network settings, such as assigning veth pair and bridge connection, configuring IP, etc.
container mode	–net=container:NAME_or_ID	A container shares a Network namespace with another container. The pod in kubernetes is multiple containers sharing a Network namespace

We only need to change to hostthe mode and share the network of the host machine!

Also, it is not recommended to use the command to start the container. If there are more than one container, it is impossible to find where the directory is mounted by itself. It is recommended to usedocker-compose

version: "3"
services:
   web:
     container_name: nginx
     image: nginx
     volumes:
       - ./html:/usr/share/nginx/html
       - ./conf/nginx.conf:/etc/nginx/nginx.conf
       - ./conf.d:/etc/nginx/conf.d
       - ./logs:/var/log/nginx
     restart: always
     network_mode: host

Note ⚠️: After using hostthe mode, do not -pexpose the port anymore. You have already used the local network, and all ports are synchronized with the host. Then port mapping is to map the local machine to the local machine. Take off your pants and fart, it’s unnecessary

If the port is mapped, it will fail to start!