1.docker 安装与基本操作

1）.安装

# 通过yum源安装docker
yum -y install docker
# 启动docker
systemctl start docker
# 开机自启
sudo systemctl enable docker

可能会遇到以下问题
/usr/bin/docker-current: Error response from daemon: Conflict. The container name "/gogs" is already in use by container 84f0d9ee2534e62de3602d65f4bbcc158fde5328a38bc2203a2486671483720b. You have to remove (or rename) that container to be able to reuse that name..
See '/usr/bin/docker-current run --help'.

2).查询所有容器

docker ps -a

3).移除容器

docker rm e3274a72e8d6

2.应用实例：emqtt

通过 Docker Hub 获取

docker pull emqx/emqx:v4.0.0

启动 docker 容器

$ docker run -d --name emqx -p 1883:1883 -p 8083:8083 -p 8883:8883 -p 8084:8084 -p 18083:18083 emqx/emqx:v4.0.0

启动后课访问后台
http://localhost:18083/

docker run -tid --name emq20 -p 1883:1883 -p 8083:8083 -p 8883:8883 -p 8084:8084 -p 18084:18083 emqttd-docker-v2.x

docker start emq20
docker stop emq20

EMQ 消息服务器默认占用的 TCP 端口包括:

1883 MQTT 协议端口
8883 MQTT/SSL 端口
8083 MQTT/WebSocket 端口
8080 HTTP API 端口
18083 Dashboard 管理控制台端口

EMQ 占用的上述端口，可通过 etc/emq.conf 配置文件的 ‘listener’ 段落设置:

TCP Listener: 1883, 127.0.0.1:1883, ::1:1883

listener.tcp.external = 0.0.0.0:1883

SSL Listener: 8883, 127.0.0.1:8883, ::1:8883

listener.ssl.external = 8883

External MQTT/WebSocket

Listenerlistener.ws.external = 8083

HTTP Management API

Listenerlistener.api.mgmt = 127.0.0.1:8080

通过注释或删除相关段落，可禁用相关 TCP 服务启动。
18083端口是 Web 管理控制占用，该端口由 emq_dashboard 插件启用。
控制台 URL: http:://localhost:18083/，默认登录用户名: admin, 密码: public

作者：书简的花果山
链接：https://www.jianshu.com/p/2f55b668e5a9
来源：简书
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

使用 docker-compose 创建简单的 static 集群

创建 docker-compose.yaml 文件

version: '3'

services:
  emqx1:
    image: emqx/emqx:v4.0.0
    environment:
    - "EMQX_NAME=emqx"
    - "EMQX_HOST=node1.emqx.io"
    - "EMQX_CLUSTER__DISCOVERY=static"
    - "EMQX_CLUSTER__STATIC__SEEDS=emqx@node1.emqx.io, emqx@node2.emqx.io"
    - "EMQX_ZONE__EXTERNAL__RETRY_INTERVAL=2s"
    - "EMQX_MQTT__MAX_TOPIC_ALIAS=10"
    volumes:
        - ./tmp/emqx.lic:/opt/emqx/etc/emqx.lic
    healthcheck:
      test: ["CMD", "/opt/emqx/bin/emqx_ctl", "status"]
      interval: 5s
      timeout: 25s
      retries: 5
    networks:
      emqx-bridge:
        aliases:
        - node1.emqx.io

  emqx2:
    image: ${IMAGE}
    environment:
    - "EMQX_NAME=emqx"
    - "EMQX_HOST=node2.emqx.io"
    - "EMQX_CLUSTER__DISCOVERY=static"
    - "EMQX_CLUSTER__STATIC__SEEDS=emqx@node1.emqx.io, emqx@node2.emqx.io"
    - "EMQX_ZONE__EXTERNAL__RETRY_INTERVAL=2s"
    - "EMQX_MQTT__MAX_TOPIC_ALIAS=10"
    volumes:
        - ./tmp/emqx.lic:/opt/emqx/etc/emqx.lic
    healthcheck:
      test: ["CMD", "/opt/emqx/bin/emqx_ctl", "status"]
      interval: 5s
      timeout: 25s
      retries: 5
    networks:
      emqx-bridge:
        aliases:
        - node2.emqx.io

  client:
    image: python:3.7.2-alpine3.9
    depends_on:
      - emqx1
      - emqx2
    tty: true
    networks:
        emqx-bridge:

networks:
  emqx-bridge:
    driver: bridge

启动 docker-compose 集群

$ docker-compose -p my_emqx up -d

查看集群

$ docker exec -it my_emqx_emqx1_1 sh -c "emqx_ctl cluster status"
Cluster status: #{running_nodes => ['emqx@node1.emqx.io','emqx@node2.emqx.io'],
                  stopped_nodes => []}

3.实例nodejs

##下载镜像
docker pull node
##装载镜像
docker images

进入docker 环境

docker run -i -t node /bin/bash