【Docker】docker swarm集群搭建和相关命令分享-天翼云

Docker swarm 集群通过 docker cli 来创建，并通过docker cli来实现应用的部署和集群的管理。

Docker swarm集群的搭建相对简单，这里使用三台虚拟机（一个管理节点，两个worker节点）来简单演示下集群的搭建过程。

|-----------------------------------------------------------------|
| hostname | IP |
|-----------------------------------------------------------------|
| master | 192.168.223.31 |
|-----------------------------------------------------------------|
| node-01 | 192.168.223.32 |
|-----------------------------------------------------------------|
| node-02 | 192.168.223.33 |
|-----------------------------------------------------------------|

虚拟机和docker-ce的安装这里就不做赘述了，安装后关闭系统默认的防火墙，关闭selinux，安装最新的docker-ce-20.10.17，并且修改docker.service，增加下面的参数配置。

# vi /lib/systemd/system/docker.service

在 ExecStart=/usr/bin/dockerd 后添加 -H tcp://0.0.0.0:2375 -H unix://var/run/docker.sock ,修改后的配置如下所示

[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix://var/run/docker.sock -H fd:// --containerd=/run/containerd/containerd.sock

修改后，记得reload配置，并且重启docker服务

# systemctl daemon-reload
# systemctl restart docker.service

下面就给大家直接贴出我搭建和使用swarm集群过程的相关命令的记录。

---初始化集群的管理节点
# docker swarm init --advertise-addr 192.168.223.31
Swarm initialized: current node (betygbmft1wkh4kmrf5wx45mc) is now a manager.

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

    docker swarm join --token SWMTKN-1-66syvw9yv8xr457lk4eviixyhd5fviw1gg3ktkwa1nkdp2rb44-14530poeryamdfwlssfynmxhk 192.168.223.31:2377

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

---从节点加入到管理节点
# docker swarm join --token SWMTKN-1-66syvw9yv8xr457lk4eviixyhd5fviw1gg3ktkwa1nkdp2rb44-14530poeryamdfwlssfynmxhk 192.168.223.31:2377
This node joined a swarm as a worker.

----查看集群的节点、状态
# docker node ls
ID                            HOSTNAME   STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
betygbmft1wkh4kmrf5wx45mc *   master     Ready     Active         Leader           20.10.17
nq4urvgyfdjedabze9p5oll6q     node-01    Ready     Active                          20.10.17
t6wtou7b5jm07qltlrp35ha85     node-02    Ready     Active                          20.10.17

---创建网络
# docker network create --opt encrypted --driver overlay --attachable webnet
7e0huckau0g8olzsyvdts8ta2

---创建nginx服务（1）
# docker service create --replicas 2 --network webnet --name nginx --publish published=80,target=80 nginx:1.22.0
gf8n3ad4k1pkxqwej6xpdthhe
overall progress: 2 out of 2 tasks 
1/2: running   [==================================================>] 
2/2: running   [==================================================>] 
verify: Service converged 

or
---创建nginx服务（2）
# docker service create --replicas 3 --network webnet --name nginx -p 80:80 nginx:1.22.0

or

---创建nginx服务（3）- 仅允许在非manager节点上运行创建的服务，即只能在node节点上运行服务的副本
# docker service create --replicas 3 --constraint node.role!=manager --network webnet --name nginx -p 80:80 nginx:1.22.0

---查看服务信息
# docker service ls
ID             NAME      MODE         REPLICAS   IMAGE          PORTS
gf8n3ad4k1pk   nginx     replicated   2/2        nginx:1.22.0   *:80->80/tcp

---查看nginx进程
# docker service ps nginx
ID             NAME      IMAGE          NODE      DESIRED STATE   CURRENT STATE                ERROR     PORTS
4vxulka6ofd2   nginx.1   nginx:1.22.0   master    Running         Running about a minute ago             
res3qre7ywcx   nginx.2   nginx:1.22.0   node-01   Running         Running 3 minutes ago    

---查看服务明细
# docker service inspect nginx          

---服务扩展
# docker service scale nginx=3
nginx scaled to 3
overall progress: 3 out of 3 tasks 
1/3: running   [==================================================>] 
2/3: running   [==================================================>] 
3/3: running   [==================================================>] 
verify: Service converged 

# docker service ps nginx
ID             NAME      IMAGE          NODE      DESIRED STATE   CURRENT STATE            ERROR     PORTS
4vxulka6ofd2   nginx.1   nginx:1.22.0   master    Running         Running 10 minutes ago             
res3qre7ywcx   nginx.2   nginx:1.22.0   node-01   Running         Running 11 minutes ago             
xpwlus8bbo6z   nginx.3   nginx:1.22.0   node-02   Running         Running 25 seconds ago

---删除服务
# docker service rm nginx
nginx

使用docker stack deploy部署portainer-ce和portainer-agent，已实现对swarm集群的监控、展示。

首先，我们在master节点和node节点上先pull需要的镜像

# docker pull portainer/portainer-ce
Using default tag: latest
latest: Pulling from portainer/portainer-ce
772227786281: Pull complete 
96fd13befc87: Pull complete 
35fb5a8b85ea: Pull complete 
6665edb137b0: Pull complete 
Digest: sha256:f716a714e6cdbb04b3f3ed4f7fb2494ce7eb4146e94020e324b2aae23e3917a9
Status: Downloaded newer image for portainer/portainer-ce:latest
docker.io/portainer/portainer-ce:latest

# docker pull portainer/agent:2.14.0
2.14.0: Pulling from portainer/agent
772227786281: Already exists 
96fd13befc87: Already exists 
3902c362cca3: Pull complete 
a215b10008ab: Pull complete 
434a8ea542bc: Pull complete 
c1c68f189caa: Pull complete 
Digest: sha256:8440499b6e1cda88442cf6c58c7fb6bad317708b796a747604ce76f65cc788ba
Status: Downloaded newer image for portainer/agent:2.14.0
docker.io/portainer/agent:2.14.0

# docker images
REPOSITORY               TAG       IMAGE ID       CREATED       SIZE
portainer/portainer-ce   latest    e8e975c3a7f0   6 days ago    278MB
portainer/agent          2.14.0    25e2624e6d49   6 days ago    166MB
nginx                    1.22.0    b3c5c59017fb   10 days ago   142MB

第二步，编写portainer-agent-stack.yml文件

version: '3.2'

services:
  agent:
    image: portainer/agent:latest
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - /var/lib/docker/volumes:/var/lib/docker/volumes
    networks:
      - agent_network
    deploy:
      mode: global
      placement:
        constraints: [node.platform.os == linux]

  portainer:
    image: portainer/portainer-ce:2.14.0
    command: -H tcp://tasks.agent:9001 --tlsskipverify
    ports:
      - "9443:9443"
      - "9000:9000"
      - "8000:8000"
    volumes:
      - portainer_data:/data
    networks:
      - agent_network
    deploy:
      mode: replicated
      replicas: 1
      placement:
        constraints: [node.role == manager]

networks:
  agent_network:
    driver: overlay
    attachable: true

volumes:
  portainer_data:

备注：上面yml文件中的constraints字段的值，即node.role == manager，来限制portainer服务仅允许运行在swarm集群的管理节点上。

第三步，部署、启动portainer-ce和portainer-agent

# docker stack deploy -c portainer-agent-stack.yml portainer 
Creating network portainer_agent_network
Creating service portainer_agent
Creating service portainer_portainer

# docker stack ls
NAME        SERVICES   ORCHESTRATOR
portainer   2          Swarm

# docker stack ps portainer 
ID             NAME                                        IMAGE                           NODE      DESIRED STATE   CURRENT STATE            ERROR     PORTS
y66nxsac6of4   portainer_agent.betygbmft1wkh4kmrf5wx45mc   portainer/agent:2.14.0          master    Running         Running 11 seconds ago             
91uog63d7mth   portainer_agent.nq4urvgyfdjedabze9p5oll6q   portainer/agent:2.14.0          node-01   Running         Running 12 seconds ago             
eahaqvm3gyzc   portainer_agent.t6wtou7b5jm07qltlrp35ha85   portainer/agent:2.14.0          node-02   Running         Running 11 seconds ago             
wy03vu1phwdq   portainer_portainer.1                       portainer/portainer-ce:latest   master    Running         Running 8 seconds ago

部署、运行成功之后，我们可以通过下面的地址来访问portainer-ce的管理页面。

https://192.168.223.31:9443/

首次登录，需要在登录页面输入一个不少于12位的密码，以创建登录用户。在主页面我们可以看到系统的一个概况。