NOTE & BLOG

Forward the domain name request to the local port

First, we will introduce the most commonly used ones. When separating front-end and back-end, sometimes we deploy some services locally such as Node.js as API service. On the local port 3300, assuming the host name is example.com, we need to access All HTTP requests on this host are forwarded to the service deployed at localhost:3300. The configuration can be written as follows:

server{
  listen 80;
  server_name  api.example.com;
  index  index.php index.html index.htm;

  location / {
    proxy_pass  http://localhost:3300; # 转发规则
    proxy_set_header Host $proxy_host; # 修改转发请求头，让8080端口的应用可以受到真实的请求
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  }
}

In this way, when accessing http://api.example.com, it will be forwarded to the local port 3300.

Forward the domain name request to another domain name

Suppose there is an alternate domain name: backup.example.com. When accessing the host backup.example.com, it is directly forwarded to the main domain name example.com. The configuration file can be written as follows:

server{
  listen 80;
  server_name  backup.example.com;
  index  index.php index.html index.htm;

  location / {
    proxy_pass  http://example.com;
    proxy_set_header Host $proxy_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  }
}

In this way, when you access http://backup.example.com, it will be forwarded to example.com

Forward a local port to another port or another domain name

Assume that the HTTP service deployed locally needs to be forwarded to port 3300 or other domain names example.com

server{
  listen 80;
  server_name localhost; # 公网ip
  index  index.php index.html index.htm;

  location / {
    proxy_pass  http://localhost:3300; # 或 http://example.com
    proxy_set_header Host $proxy_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  }
}

In this way, when accessing http://localhost, it will be forwarded to the local port 3300 or http://example.com

Note: adding / or not adding / at the end of location

When configuring proxy_pass proxy forwarding, if the following url is added with /, it indicates the absolute root path; if there is no /, it indicates the relative path.

For example

1. with /

server_name example.com
location /data/ {
    proxy_pass http://localhost/;
}

Accessing http://example.com/data/index.html will be forwarded to http://localhost/index.html

2. without /

server_name example.com
location /data/ {
    proxy_pass http://localhost;
}

Accessing http://example.com/data/index.html will be forwarded to http://localhost/data/index.html