Docker下的Nginx自动化修改监听端口

1 docker-compose.yaml

原理就是通过envsubst命令将含有系统变量的脚本替换环境变量后生成新的配置文件。

#示例1 替换文件内的全部变量
 nginx:
    image: nginx:1.20.1
    restart: always
    environment:
       - SERVER_PORT=${SERVER_PORT}
    volumes:
       - "./htdocs:/usr/share/nginx/html"
       - "./conf/nginx/conf.d:/etc/nginx/conf.d"
       - "./conf/nginx/nginx.conf:/etc/nginx/nginx.conf"
    command: /bin/sh -c "envsubst  < /etc/nginx/conf.d/default.conf.template > /etc/nginx/conf.d/default.conf && exec nginx -g 'daemon off;'"
    network_mode: "host"

#示例2 替换文件内的指定变量
#备注：采用脚本的方式替换指定变量的原因是，基于示例1直接写执行命令，总是不成功。
  nginx:
    image: nginx:1.20.1
    restart: always
    environment:
       - NGINX_PORT=${SERVER_PORT}
    volumes:
       - "./htdocs:/usr/share/nginx/html"
       - "./conf/nginx/conf.d:/etc/nginx/conf.d"
       - "./conf/nginx/nginx.conf:/etc/nginx/nginx.conf"
    command: ["/bin/sh", "-c", "/etc/nginx/conf.d/start.sh"]
    network_mode: "host"

2 start.sh

nginx镜像内置envsubst命令，通过该命令，引用系统变量生成新的配置文件，同时可指定替换的变量，如下脚本，替换指定的变量${NGINX_PORT}。

#! /bin/sh
envsubst '${NGINX_PORT}' < /etc/nginx/conf.d/default.conf.template > /etc/nginx/conf.d/default.conf && exec nginx -g 'daemon off;'