Port missing after Nginx reverse proxy

The cause of the incident was the external mapping port access problem of GitLab within the company. Using port 80/443 in the internal network to access normally, using a non-80 port to access the home page will automatically jump to port 80. Manual port access is normal, but this is extremely affect the user experience.

1. Background description

The intranet uses a container to build a GitLabplatform, the internal Nginxport is 8081, and IP+Portthe access is normal by using the form. After deploying the reverse management from other machines Nginx, the access using the domain name is also normal, but the reverse management port is changed to non- Port 80/443, when accessing the home page through the form of domain name and port, it will jump to port 80, resulting in access failure, as shown below:

http://git.example.com:1443 — > http://git.example.com

After manually adding the port to the redirected URL, the access is normal again, so it is guessed that there may be a Nginxconfiguration problem.

2. Problem solving

1. The cause of the problem

NginxDue to the loss of the port, Nginxthe port information was not correctly transmitted to the backend, and the configuration was not correctNginx

2. Problem solving

server {
    
    
    listen 8888;
    server_name localhost;
    location / {
    
    
        proxy_set_header Host $host:$server_port; 这一行是关键
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header REMOTE-HOST $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

proxy_set_header Host $host:$server_port;This line is the key, must be set to get the real port.