Docker Swarm

Swarm简介

简单说 Swarm就是实时管理部署多个docker container(可在不同机器上), 可单独启动和停止某个conntainer, 并可实时重新加载环境变量, docker-compose的配置的变量等

• 注意:
  • Linux下可以实现管理多节点
  • Windows和Mac OS下只能管理单节点
  • Manager是管理节点, 主节点, node是被管理节点

Swarm Manager

• 启动 Manager 节点
  docker swarm init --advertise-addr <MANAGER-IP>
  其中单节点swarm无需输入--advertise-addr
  输出结果:

$ docker swarm init --advertise-addr 192.168.99.100
Swarm initialized: current node (dxn1zf6l61qsb1josjja83ngz) is now a manager.

To add a worker to this swarm, run the following command:

    docker swarm join \
    --token SWMTKN-1-49nj1cmql0jkz5s954yi3oex3nedyz0fb0xx14ie39trti4wxv-8vxv8rssmk743ojnwacrr2e7c \
    192.168.99.100:2377

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

• docker info 显示swarm信息

$ docker info

Containers: 2
Running: 0
Paused: 0
Stopped: 2
  ...snip...
Swarm: active
  NodeID: dxn1zf6l61qsb1josjja83ngz
  Is Manager: true
  Managers: 1
  Nodes: 1
  ...snip...

• docker node ls 显示节点信息:

$ docker node ls

ID                           HOSTNAME  STATUS  AVAILABILITY  MANAGER STATUS
dxn1zf6l61qsb1josjja83ngz *  manager1  Ready   Active        Leader

在另一台机器上加入node节点

• docker swarm join-token worker 获取加入节点命令

$ docker swarm join-token worker

To add a worker to this swarm, run the following command:

    docker swarm join \
    --token SWMTKN-1-49nj1cmql0jkz5s954yi3oex3nedyz0fb0xx14ie39trti4wxv-8vxv8rssmk743ojnwacrr2e7c \
    192.168.99.100:2377

• docker swarm join 新增node节点

$ docker swarm join \
  --token  SWMTKN-1-49nj1cmql0jkz5s954yi3oex3nedyz0fb0xx14ie39trti4wxv-8vxv8rssmk743ojnwacrr2e7c \
  192.168.99.100:2377

This node joined a swarm as a worker.

• docker node ls 显示已加入节点信息:

ID                           HOSTNAME  STATUS  AVAILABILITY  MANAGER STATUS
03g1y59jwfg7cf99w4lt0f662    worker2   Ready   Active
9j68exjopxe7wfl6yuxml7a7j    worker1   Ready   Active
dxn1zf6l61qsb1josjja83ngz *  manager1  Ready   Active        Leader

在节点上启动docker service(container)

• docker service create --replicas 1 --name container_name image_name:tag cmd

$ docker service create --replicas 1 --name helloworld alpine ping docker.com

9uk4639qpg7npwf3fn2aasksr

replicas: 启动container数量
上面命令会在当前机器节点启动helloworld container, 在conntainer里运行ping命令

• docker service ls 列出service状态:

$ docker service ls

ID            NAME        SCALE  IMAGE   COMMAND
9uk4639qpg7n  helloworld  1/1    alpine  ping docker.com

在Manager节点上管理Node节点:

• docker service inspect --pretty <SERVICE-ID> 查看node节点启动信息:

[manager1]$ docker service inspect --pretty helloworld

ID:     9uk4639qpg7npwf3fn2aasksr
Name:       helloworld
Service Mode:   REPLICATED
 Replicas:      1
Placement:
UpdateConfig:
 Parallelism:   1
ContainerSpec:
 Image:     alpine
 Args:  ping docker.com
Resources:
Endpoint Mode:  vip

• docker service ps <SERVICE-ID> 显示node节点container信息

[manager1]$ docker service ps helloworld

NAME                                    IMAGE   NODE     DESIRED STATE  CURRENT STATE           ERROR               PORTS
helloworld.1.8p1vev3fq5zm0mi8g0as41w35  alpine  worker2  Running        Running 3 minutes

• docker service rm helloworld 删除节点container
• docker service update --image image_name:tag container_name 更新节点container, 应用新的所有配置, 环境变量等

$ docker service update --image redis:3.0.7 redis
redis