使用Docker Compose 实现nginx负载均衡

查看所有docker网络

docker network ls    /*  NETWORK ID     NAME         DRIVER       SCOPE  b832b166.6ca9a    bridge        bridge       local  373be82d3a6a    composetest_default  bridge       local  a360425082c4    host         host        local  154f600f0e90    none         null        local    */    // composetest_default 是上一篇介绍Compose时，docker-compose.yml文件所在的目录名，  // 所以，用docker-compose创建的容器会默认创建一个以目录名为网络名的网络，并且是dridge（桥接）类型  

指定容器IP地址

官网文档地址：https://docs.docker.com/compose/compose-file/#ipv4_address-ipv6_address

继续编写上一篇《12.使用Docker Compose容器编排工具》文章中的docker-compose.yml

version: "3"  services:    web1:      container_name: web1      image: "centos:httpd"      ports:        - "8080:80"      privileged: true      volumes:        - "/app/www/web1/:/var/www/html/"      command: ['/usr/sbin/init']      networks:        nginx-lsb:          ipv4_address: 192.169.0.3    web2:      container_name: web2      image: "centos:httpd"      ports:        - "8081:80"      privileged: true      volumes:        - "/app/www/web2/:/var/www/html/"      command: ['/usr/sbin/init']      networks:        nginx-lsb:          ipv4_address: 192.169.0.2  networks:    nginx-lsb:      driver: bridge      ipam:        config:          - subnet: 192.169.0.0/16  

使用docker-compose启动容器

docker-compose up -d

查看容器是否启动，并确认是否创建了网络 nginx-lsb

// 可以查看当前docker-compose.yml配置的容器组里的容器状态  docker-compose ps    docker network ls    /*  NETWORK ID     NAME          DRIVER       SCOPE  b832b166.6ca9a    bridge         bridge       local  373be82d3a6a    composetest_default   bridge       local  de6f5b8df1c8    composetest_nginx-lsb  bridge       local  a360425082c4    host          host        local  154f600f0e90    none          null        local  */    // 创建了nginx-lsb网络，命名是容器组项目的 文件名开头_网络名    

查看网络 nginx-lsb的详情

docker network inspect composetest_nginx-lsb    // 详情里面可以看到使用这个网络的每个容器的ip    如：    /*  ...   "Containers": {        "039aa860ef04f20a7566fdc943fb4398a61d2ad6dd3e373b17c86ac778af89e3": {          "Name": "web2",          "EndpointID": "1bc206661179e65999015f132c2889d3d4365b8d42b8a89cf9c260016fedd5ee",          "MacAddress": "02:42:c0:a9:00:02",          "IPv4Address": "192.169.0.2/16",          "IPv6Address": ""        },        "437ad7a07da8e46c0abaf845c4b08425338009fbe972bde69478cf47c75c315b": {          "Name": "web1",          "EndpointID": "5a36e602a5364ee9ad06e9816d09e3966d56ebf06b9394ebc25b8bcee8846607",          "MacAddress": "02:42:c0:a9:00:03",          "IPv4Address": "192.169.0.3/16",          "IPv6Address": ""        }      },  ...  */    

使用 env_file环境文件：

简单可以理解为：在docker-compose.yml中定义变量，引用在外部.env文件中进行变量定义

官方文档地址：

// 还是在composetest目录中定义个 .env文件，用来存放变量  web1_addr=192.169.0.2  web2_addr=192.169.0.3    // 修改docker-compose.yml文件，加入变量定义  version: "3"  services:    web1:      container_name: web1      image: "centos:httpd"      ports:        - "8080:80"      privileged: true      volumes:        - "/app/www/web1/:/var/www/html/"      command: ['/usr/sbin/init']      networks:        nginx-lsb:          ipv4_address: ${web1_addr}    web2:      container_name: web2      image: "centos:httpd"      ports:        - "8081:80"      privileged: true      volumes:        - "/app/www/web2/:/var/www/html/"      command: ['/usr/sbin/init']      networks:        nginx-lsb:          ipv4_address: ${web2_addr}  networks:    nginx-lsb:      driver: bridge      ipam:        config:          - subnet: 192.169.0.0/16    

重新启动composetest项目，并查看网络详情，确认容器ip是否设置成功

// 重新启动composetest项目  docker-compose up -d    // 查看网络详情  docker network inspect composetest_nginx-lsb    

在composetest项目中添加一台nginx主机作为负载均衡主机

// 在.env文件里添加一个变量 nginx_lsb  web1_addr=192.169.0.2  web2_addr=192.169.0.3  nginx_lsb=192.169.0.100    // 修改docker-compose.yml文件，加入变量定义  version: "3"  services:    nginx-lsb:      container_name: nginx-lsb      image: "centos:nginx"      ports:         - "8000:80"      privileged: true      volumes:        - "/app/nginx/nginx.conf:/etc/nginx/nginx.conf"      networks:        nginx-lsb:          ipv4_address: ${nginx_lsb}    web1:      container_name: web1      image: "centos:httpd"      ports:        - "8080:80"      privileged: true      volumes:        - "/app/www/web1/:/var/www/html/"      command: ['/usr/sbin/init']      networks:        nginx-lsb:          ipv4_address: ${web1_addr}    web2:      container_name: web2      image: "centos:httpd"      ports:        - "8081:80"      privileged: true      volumes:        - "/app/www/web2/:/var/www/html/"      command: ['/usr/sbin/init']      networks:        nginx-lsb:          ipv4_address: ${web2_addr}  networks:    nginx-lsb:      driver: bridge      ipam:        config:          - subnet: 192.169.0.0/16    // 重新启动composetest项目  docker-compose up -d    

修改nginx.conf配置文件，配置负载均衡

upstream mydocker {    server 192.169.0.2;    server 192.169.0.3;  }    server {    listen 80；    server_name mydocker;    location / {      proxy_set_header Host $host;      proxy_set_header X-Real-IP $remote_addr;      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;      proxy_buffering off;      proxy_pass http://mydocker;    }  }    

重新启动nginx-lsb，加载配置文件

docker-composer restart nginx-lsb  

访问 http://主机IP地址:8000，测试主机负载均衡！

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