需求：部署前端镜像时需要动态修改nginx反向代理的后端服务的ip地址
- 原.conf配置调整，改为嵌入变量的文件模版
- Dockerfile 修改，通过envsubst将换将变量注入模版后再运行nginx
- docker-compose配置，通过environment动态修改变量
default.conf.tmplate（原default.conf）
动态变量：${MY_IP}
server {listen 80;server_name localhost;location / {root /usr/share/nginx/html;try_files $uri /index.html;}location /api{proxy_pass http://${MY_IP}:18892;}}
Dockerfile
如果有多个变量可用逗号隔开，envsubst '$MY_IP,$MY_PORT'
FROM nginx:1.20.2-alpineCOPY dist /usr/share/nginx/htmlCOPY nginx.conf /etc/nginx/nginx.conf
# 拷贝模板
COPY default.conf.tmplate /etc/nginx/conf.d
# 切换目录
WORKDIR /etc/nginx/conf.d
# 将环境变量注入模版
ENTRYPOINT envsubst '$MY_IP' < default.conf.tmplate > default.conf && cat default.conf && nginx -g 'daemon off;'EXPOSE 80
docker-compose.yml
注意environment下的变量名称MY_IP要与上述对应
environment:- MY_IP=server2
yml完整配置示例：
通过同一套镜像部署两个web项目,后端对应不同的数据库，前端对应不同的后端
version: '2'
networks:myapp:driver: bridge
services:server1:image: [ip]:5000/servercontainer_name: server1restart: alwaysenvironment:- spring.datasource.url=jdbc:mysql://[ip]:3306/dbs1?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=CTT- JAVA_OPTS=-Dlog4j2.formatMsgNoLookups=truenetworks:- myappfront1:image: [ip]:5000/frontcontainer_name: front1restart: alwaysenvironment:- MY_IP=server1depends_on:- server1links:- server1ports:- "8095:80"networks:- myappserver2:image: [ip]:5000/servercontainer_name: server2restart: alwaysenvironment:- spring.datasource.url=jdbc:mysql://[ip]:3306/dbs2?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=CTT- JAVA_OPTS=-Dlog4j2.formatMsgNoLookups=truenetworks:- myappfront2:image: 10.1.58.6:5000/frontcontainer_name: front2restart: alwaysenvironment:- MY_IP=server2depends_on:- server2links:- server2ports:- "8096:80"networks:- myapp
