使用Docker Compose 實現(xiàn)nginx負載均衡的方法步驟

更新時間：2019年05月22日 10:42:45 作者：董俊俊

這篇文章主要介紹了使用Docker Compose 實現(xiàn)nginx負載均衡的方法步驟，小編覺得挺不錯的，現(xiàn)在分享給大家，也給大家做個參考。一起跟隨小編過來看看吧

以Docker的網(wǎng)絡(luò)管理，容器的IP設(shè)置為基礎(chǔ)知識實現(xiàn)Nginx負載均衡

查看所有docker網(wǎng)絡(luò)

docker network ls

/*
NETWORK ID     NAME         DRIVER       SCOPE
b832b168ca9a    bridge        bridge       local
373be82d3a6a    composetest_default  bridge       local
a360425082c4    host         host        local
154f600f0e90    none         null        local

*/

// composetest_default 是上一篇介紹Compose時，docker-compose.yml文件所在的目錄名，
// 所以，用docker-compose創(chuàng)建的容器會默認創(chuàng)建一個以目錄名為網(wǎng)絡(luò)名的網(wǎng)絡(luò)，并且是dridge（橋接）類型

指定容器IP地址

官網(wǎng)文檔地址：https://docs.docker.com/compose/compose-file/#ipv4_address-ipv6_address

繼續(xù)編寫上一篇《12.使用Docker Compose容器編排工具》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啟動容器

docker-compose up -d

查看容器是否啟動，并確認是否創(chuàng)建了網(wǎng)絡(luò) nginx-lsb

// 可以查看當前docker-compose.yml配置的容器組里的容器狀態(tài)
docker-compose ps

docker network ls

/*
NETWORK ID     NAME          DRIVER       SCOPE
b832b168ca9a    bridge         bridge       local
373be82d3a6a    composetest_default   bridge       local
de6f5b8df1c8    composetest_nginx-lsb  bridge       local
a360425082c4    host          host        local
154f600f0e90    none          null        local
*/

// 創(chuàng)建了nginx-lsb網(wǎng)絡(luò)，命名是容器組項目的 文件名開頭_網(wǎng)絡(luò)名

查看網(wǎng)絡(luò) nginx-lsb的詳情

docker network inspect composetest_nginx-lsb

// 詳情里面可以看到使用這個網(wǎng)絡(luò)的每個容器的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": "5a36e602a5364ee9ad06e9816d09e3966d56ebf06b9394ebc25b8bcee9546607",
        "MacAddress": "02:42:c0:a9:00:03",
        "IPv4Address": "192.169.0.3/16",
        "IPv6Address": ""
      }
    },
...
*/

使用 env_file環(huán)境文件：

簡單可以理解為：在docker-compose.yml中定義變量，引用在外部.env文件中進行變量定義

官方文檔地址：https://docs.docker.com/compose/compose-file/#env_file

// 還是在composetest目錄中定義個 .env文件，用來存放變量
web1_addr=192.169.0.2
web2_addr=192.169.0.3

// 修改docker-compose.yml文件，加入變量定義
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

重新啟動composetest項目，并查看網(wǎng)絡(luò)詳情，確認容器ip是否設(shè)置成功

// 重新啟動composetest項目
docker-compose up -d

// 查看網(wǎng)絡(luò)詳情
docker network inspect composetest_nginx-lsb

在composetest項目中添加一臺nginx服務(wù)器作為負載均衡服務(wù)器

// 在.env文件里添加一個變量 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，加入變量定義
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

// 重新啟動composetest項目
docker-compose up -d

修改nginx.conf配置文件，配置負載均衡

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;
  }
}

重新啟動nginx-lsb，加載配置文件