摘要：以的網絡管理，容器的設置為基礎知識實現負載均衡查看所有網絡是上一篇介紹時，文件所在的目錄名，所以，用創建的容器會默認創建一個以目錄名為網絡名的網絡，并且是橋接類型指定容器地址官網文檔地址繼續編寫上一篇使用容器編排工具文章中的

以Docker的網絡管理，容器的IP設置為基礎知識實現Nginx負載均衡

查看所有docker網絡

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創建的容器會默認創建一個以目錄名為網絡名的網絡，并且是dridge（橋接）類型

指定容器IP地址

官網文檔地址：https://docs.docker.com/compo...

繼續編寫上一篇《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，并確認是否創建了網絡 nginx-lsb

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

// 創建了nginx-lsb網絡，命名是容器組項目的 文件名開頭_網絡名

查看網絡 nginx-lsb的詳情

docker network inspect composetest_nginx-lsb

// 詳情里面可以看到使用這個網絡的每個容器的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/compo...

// 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，并查看網絡詳情，確認容器ip是否設置成功

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

// 查看網絡詳情
docker network inspect composetest_nginx-lsb

在composetest項目中添加一臺nginx服務器作為負載均衡服務器

// 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

docker-composer restart nginx-lsb

訪問 http://服務器IP地址:8000，測試服務器負載均衡！

注意：上一篇已經在兩臺httpd服務器上放置了不同的web文件

原文鏈接：http://www.mi360.cn/articles/20