13.使用Docker Compose 實現nginx負載均衡

時間 2019-12-06

標籤使用 docker compose 實現 nginx 負載均衡欄目 Docker 简体版

原文原文鏈接

以Docker的網絡管理，容器的IP設置爲基礎知識實現Nginx負載均衡

查看全部docker網絡html

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，
// 因此，用docker-compose建立的容器會默認建立一個以目錄名爲網絡名的網絡，而且是dridge（橋接）類型

指定容器IP地址nginx

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

繼續編寫上一篇《12.使用Docker Compose容器編排工具》文章中的docker-compose.ymldocker

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啓動容器centos

docker-compose up -d

查看容器是否啓動，並確認是否建立了網絡 nginx-lsb服務器

// 能夠查看當前docker-compose.yml配置的容器組裏的容器狀態
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
*/

// 建立了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的詳情網絡

docker network inspect composetest_nginx-lsb

// 詳情裏面能夠看到使用這個網絡的每一個容器的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：app

簡單能夠理解爲：在docker-compose.yml中定義變量，引用在外部.env文件中進行變量定義composer

官方文檔地址：https://docs.docker.com/compo...負載均衡

// 仍是在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

從新啓動composetest項目，並查看網絡詳情，確認容器ip是否設置成功

// 從新啓動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服務器做爲負載均衡服務器

// 在.env文件裏添加一個變量 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

// 從新啓動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;
    }
}

從新啓動nginx-lsb，加載配置文件