docker学习6-docker-compose容器集群编排

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docker-compose

简介

Docker-Compose项目是Docker官方的开源项目，负责实现对Docker容器集群的快速编排。
Docker-Compose将所管理的容器分为三层，分别是工程（project），服务（service）以及容器（container）。
Docker-Compose运行目录下的所有文件（docker-compose.yml，extends文件或环境变量文件等）组成一个工程，若无特殊指定工程名即为当前目录名。一个工程当中可包含多个服务，每个服务中定义了容器运行的镜像，参数，依赖。一个服务当中可包括多个容器实例，Docker-Compose并没有解决负载均衡的问题，因此需要借助其它工具实现服务发现及负载均衡。

Docker-Compose的工程配置文件默认为docker-compose.yml，可通过环境变量COMPOSE_FILE或-f参数自定义配置文件，其定义了多个有依赖关系的服务及每个服务运行的容器。

安装

docker-compose使用pip安装即可

pip install docker-compose

使用docker-compose version查看版本

我的centos中有python3，所以直接查看提示docker-compose命令不存在

默认的Python版本是2.7，我是使用3.6的pip安装的，所以去、/usr/local/python3/bin目录下找到docker-compose创建软连接

[root@bogon bin]# ln -s /usr/local/python3/bin/docker-compose /usr/bin/docker-compose

[root@bogon /]# docker-compose version
docker-compose version 1.24.1, build 4667896
docker-py version: 3.7.3
CPython version: 3.6.2
OpenSSL version: OpenSSL 1.0.2k-fips 26 Jan 2017
[root@bogon /]#

实例

docker-compose.yml文件

docker-compose已经安装成功，接下来去https://hub.docker.com上找个项目部署练练手，项目地址：https://hub.docker.com/r/easymock/easymock

docker-compose 文件内容

version: '3'

services:
  mongodb:
    image: mongo:3.4
    volumes:
      # ./data/db 数据库文件存放地址，根据需要修改为本地地址
      - './data/db:/data/db'
    networks:
      - easy-mock
    restart: always

  redis:
    image: redis:4.0.6
    command: redis-server --appendonly yes
    volumes:
      # ./data/redis redis 数据文件存放地址，根据需要修改为本地地址
      - './data/redis:/data'
    networks:
      - easy-mock
    restart: always

  web:
    image: easymock/easymock:1.6.0
    command: /bin/bash -c "npm start"
    ports:
      - 7300:7300
    volumes:
      # 日志地址，根据需要修改为本地地址
      - './logs:/home/easy-mock/easy-mock/logs'
      # 配置地址，请使用本地配置地址替换
      # - './production.json:/home/easy-mock/easy-mock/config/production.json'
    networks:
      - easy-mock
    restart: always

networks:
  easy-mock:

使用方式

1. 安装 docker-compose
2. 新建文件 docker-compose.yml 并将上面 docker-compose 文件内容复制进入 docker-compose.yml，然后将内容中注释位置替换为自己需要的本地地址即可。主要有三个需要替换的地方，数据库文件存储位置，日志文件存储位置，自定义配置文件本地地址。
3. 启动：docker-compose up -d

自定义配置参考 easymock readme 中的配置小节。

注意

• 使用容器方式运行不需要指定 db 和 redis 参数
• production.json 配置中注意以下问题

{
  "port": 7300,
  "host": "0.0.0.0",
  "pageSize": 30,
  "proxy": false,
  "db": "mongodb://mongodb/easy-mock" # host 请务必替换为mongodb, 而非 localhost
  "unsplashClientId": "",
  "redis": {
    "keyPrefix": "[Easy Mock]",
    "port": 6379,
    "host": "redis", // 请勿使用 localhost，换 "redis"
    "password": "",
    "db": 0
  },
  ......
  ......
}

在本地新建一个文件夹/home/leslie/easymock，接着新建文件docker-compose.yml，把上面的内容写入到这个文件里，如下步骤

[root@bogon easymock]# ls
docker-aompose.yal
[root@bogon easymock]# less docker-aompose.yal
version: '3'

services:
mongodb:
image: mongo:3.4
volumes:
# ./data/db 数据库文件存放地址，根据需要修改为本地地址
- './data/db:/data/db'
networks:
- easy-mock
restart: always

redis:
image: redis:4.0.6
command: redis-server --appendonly yes
volumes:
# ./data/redis redis 数据文件存放地址，根据需要修改为本地地址
- './data/redis:/data'
networks:
- easy-mock
restart: always

web:
image: easymock/easymock:1.6.0
command: /bin/bash -c "npm start"
ports:
- 7300:7300 volumes:

docker-compose up启动

使用docker-compose up 指令启动服务,可以看到依次启动三个容器

• Creating easymock_redis_1 ... done
• Creating easymock_mongodb_1 ... done
• Creating easymock_web_1 ... done

web_1 |
web_1 | > easy-mock@1.6.0 start /home/easy-mock/easy-mock
web_1 | > cross-env NODE_ENV=production node app
web_1 |
web_1 | WARNING: NODE_ENV value of 'production' did not match any deployment config file names.
web_1 | WARNING: See https://github.com/lorenwest/node-config/wiki/Strict-Mode
web_1 | server started at http://0.0.0.0:7300
mongodb_1 | 2019-09-04T07:14:47.881+0000 I NETWORK [thread1] connection accepted from 172.18.0.2:43855 #2 (1 connection now open)
web_1 | events.js:182
web_1 | throw er; // Unhandled 'error' event
web_1 | ^
web_1 |
web_1 | Error: EACCES: permission denied, open 'logs/2019-09-04-info.log'
mongodb_1 | 2019-09-04T07:14:47.907+0000 I - [conn2] end connection 172.18.0.2:43855 (1 connection now open)
web_1 | npm ERR! code ELIFECYCLE
web_1 | npm ERR! errno 1

web_1 | npm ERR! easy-mock@1.6.0 start: `cross-env NODE_ENV=production node app`

如果看到以下报错，给log文件夹加个权限即可

chmod 777 logs

ey: { project: 1, create_at: -1 }, name: "project_1_create_at_-1", ns: "easy-mock.mocks", background: true }
mongodb_1 | 2019-09-04T07:17:34.582+0000 I INDEX [conn2] build index on: easy-mock.groups properties: { v: 2, unique: true, key: { name: 1 }, name: "name_1", ns: "easy-mock.groups", background: true }
mongodb_1 | 2019-09-04T07:17:34.589+0000 I INDEX [conn3] build index on: easy-mock.projects properties: { v: 2, key: { user: 1, members: 1, create_at: -1 }, name: "user_1_members_1_create_at_-1", ns: "easy-mock.projects", background: true }
mongodb_1 | 2019-09-04T07:17:34.596+0000 I INDEX [conn5] build index on: easy-mock.mock_counts properties: { v: 2, key: { mock: 1, create_at: -1 }, name: "mock_1_create_at_-1", ns: "easy-mock.mock_counts", background: true }
mongodb_1 | 2019-09-04T07:17:34.603+0000 I INDEX [conn7] build index on: easy-mock.user_project properties: { v: 2, unique: true, key: { project: 1, user: 1 }, name: "project_1_user_1", ns: "easy-mock.user_project", background: true }
mongodb_1 | 2019-09-04T07:17:34.609+0000 I INDEX [conn6] build index on: easy-mock.user_group properties: { v: 2, unique: true, key: { group: 1, user: 1 }, name: "group_1_user_1", ns: "easy-mock.user_group", background: true }
mongodb_1 | 2019-09-04T07:17:34.609+0000 I INDEX [conn4] build index done. scanned 0 total records. 0 secs
mongodb_1 | 2019-09-04T07:17:34.610+0000 I INDEX [conn1] build index done. scanned 0 total records. 0 secs
mongodb_1 | 2019-09-04T07:17:34.610+0000 I INDEX [conn2] build index done. scanned 0 total records. 0 secs
mongodb_1 | 2019-09-04T07:17:34.611+0000 I INDEX [conn3] build index done. scanned 0 total records. 0 secs
mongodb_1 | 2019-09-04T07:17:34.611+0000 I INDEX [conn5] build index done. scanned 0 total records. 0 secs
mongodb_1 | 2019-09-04T07:17:34.612+0000 I INDEX [conn7] build index done. scanned 0 total records. 0 secs
mongodb_1 | 2019-09-04T07:17:34.622+0000 I INDEX [conn3] build index on: easy-mock.groups properties: { v: 2, key: { user: 1, create_at: -1 }, name: "user_1_create_at_-1", ns: "easy-mock.groups", background: true }
mongodb_1 | 2019-09-04T07:17:34.623+0000 I INDEX [conn3] build index done. scanned 0 total records. 0 secs
mongodb_1 | 2019-09-04T07:17:34.626+0000 I INDEX [conn6] build index done. scanned 0 total records. 0 secs

就正常了

docker-compose挂后台运行

挂后台运行需加-d参数

docker-compose up -d

查看正在启动的docker容器使用docker ps

[root@bogon easymock]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
188db7406653 redis:4.0.6 "docker-entrypoint.s…" 32 seconds ago Up 28 seconds 6379/tcp easymock_redis_1
0d74514cecb4 mongo:3.4 "docker-entrypoint.s…" 32 seconds ago Up 29 seconds 27017/tcp easymock_mongodb_1
70d37e69706e easymock/easymock:1.6.0 "/bin/bash -c 'npm s…" 32 seconds ago Up 29 seconds 0.0.0.0:7300->7300/tcp easymock_web_1
2c83aab72e3e tomcat "catalina.sh run" 21 hours ago Up 4 hours 0.0.0.0:8089->8080/tcp leslietomcat
[root@bogon easymock]#

docker-compose停止运行

停掉服务使用docker-compose down

docker-compose down

[root@bogon easymock]# docker-compose down
Stopping easymock_redis_1 ... done
Stopping easymock_mongodb_1 ... done
Stopping easymock_web_1 ... done
Removing easymock_redis_1 ... done
Removing easymock_mongodb_1 ... done
Removing easymock_web_1 ... done
Removing network easymock_easy-mock
[root@bogon easymock]#