docker学习(九)docker swarm集群
钮实
前言
Docker Swarm是Docker原生态的集群技术，swarm 集群由管理节点（manager）和工作节点（work node）组成。
swarm mananger：主节点，负责整个集群的管理工作包括集群配置、服务管理等所有跟集群有关的工作；
work node：工作节点，主要负责运行相应的服务来执行任务（task）。
一、环境准备
1、安装docker
略
2、准备两台机器
manager 172.16.10.151
node 172.16.10.153
二、安装主节点
安装主节点，生成token，其他工作节点使用该token加入集群
[root@swarm-master ~]# docker swarm init --advertise-addr 172.16.10.151
Swarm initialized: current node (yyjg5a442rncjuh58xdsel5a3) is now a manager.
To add a worker to this swarm, run the following command:
docker swarm join --token SWMTKN-1-4mi806upco3hjeiuu4c8boeehml9fuo5u7mnnode3o23h7ljuj-44nnu8s9b93vxob29tix73vhc 172.16.10.151:2377
To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.
查看集群
[root@swarm-master ~]# docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION
yyjg5a442rncjuh58xdsel5a3 * swarm-master Ready Active Leader 18.06.3-ce
三、安装从节点
使用上面的token
[root@swarm-node02 ~]# docker swarm join --token SWMTKN-1-4mi806upco3hjeiuu4c8boeehml9fuo5u7mnnode3o23h7ljuj-44nnu8s9b93vxob29tix73vhc 172.16.10.151:2377
This node joined a swarm as a worker.
在主节点上查看集群
[root@swarm-master ~]# docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION
yyjg5a442rncjuh58xdsel5a3 * swarm-master Ready Active Leader 18.06.3-ce
y35ggyr28c1q2ltolvhva8d82 swarm-node02 Ready Active 20.10.11
四、常用命令
1、docker node
[root@swarm-master ~]# docker node --help
Usage: docker node COMMAND
Manage Swarm nodes
Commands:
demote Demote one or more nodes from manager in the swarm 将管理节点降级为普通节点
inspect Display detailed information on one or more nodes 查看节点的详细信息
ls List nodes in the swarm 查看节点列表
promote Promote one or more nodes to manager in the swarm 将普通节点升级为管理节点
ps List tasks running on one or more nodes, defaults to current node 查看运行的任务
rm Remove one or more nodes from the swarm 从集群中删除节点
update Update a node 更新节点状态
Run 'docker node COMMAND --help' for more information on a command.
2、docker service
[root@swarm-master ~]# docker service --help
Usage: docker service COMMAND
Manage services
Commands:
create Create a new service 创建新的服务
inspect Display detailed information on one or more services 查看服务详细信息
logs Fetch the logs of a service or task 查看服务日志
ls List services 查看服务列表
ps List the tasks of one or more services 查看服务任务信息
rm Remove one or more services 删除服务
rollback Revert changes to a service's configuration 回滚服务
scale Scale one or multiple replicated services 扩容缩容
update Update a service 更新服务
Run 'docker service COMMAND --help' for more information on a command.
五、测试
1、下载nginx镜像
[root@swarm-master ~]# docker pull nginx
Using default tag: latest
latest: Pulling from library/nginx
e5ae68f74026: Pull complete
21e0df283cd6: Pull complete
ed835de16acd: Pull complete
881ff011f1c9: Pull complete
77700c52c969: Pull complete
44be98c0fab6: Pull complete
Digest: sha256:9522864dd661dcadfd9958f9e0de192a1fdda2c162a35668ab6ac42b465f0603
Status: Downloaded newer image for nginx:latest
2、创建服务
[root@swarm-master ~]# docker service create --replicas 1 --name nginx-test nginx:latest
k8r71cut7ofe26r26rha4b3ny
overall progress: 1 out of 1 tasks
1/1: running [==================================================>]
verify: Service converged
3、查看服务
[root@swarm-master ~]# docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
k8r71cut7ofe nginx-test replicated 1/1 nginx:latest
4、查看任务
[root@swarm-master ~]# docker service ps nginx-test
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
4lsajhzyk84o nginx-test.1 nginx:latest swarm-master Running Running 5 minutes ago
5、扩容
[root@swarm-master ~]# docker service scale nginx-test=2
nginx-test scaled to 2
overall progress: 2 out of 2 tasks
1/2: running [==================================================>]
2/2: running [==================================================>]
verify: Service converged
再次查看任务，可以看出两个任务分别运行在两个节点上
[root@swarm-master ~]# docker service ps nginx-test
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
4lsajhzyk84o nginx-test.1 nginx:latest swarm-master Running Running 10 minutes ago
d3vrxeuc61o9 nginx-test.2 nginx:latest swarm-node02 Running Running 58 seconds ago
6、更新服务
[root@swarm-master ~]# docker service update --image=nginx:1.21 nginx-test
nginx-test
overall progress: 2 out of 2 tasks
1/2: running [==================================================>]
2/2: running [==================================================>]
verify: Service converged
查看服务，镜像已经更新成 nginx:1.21
[root@swarm-master ~]# docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
k8r71cut7ofe nginx-test replicated 2/2 nginx:1.21
[root@swarm-master ~]# docker service ps nginx-test
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
t3uqo4hdnapt nginx-test.1 nginx:1.21 swarm-master Running Running 28 seconds ago
4lsajhzyk84o \_ nginx-test.1 nginx:latest swarm-master Shutdown Shutdown 28 seconds ago
6aiwhotqeuoj nginx-test.2 nginx:1.21 swarm-node02 Running Running 25 seconds ago
d3vrxeuc61o9 \_ nginx-test.2 nginx:latest swarm-node02 Shutdown Shutdown 26 seconds ago
7、服务回滚
[root@swarm-master ~]# docker service update --rollback nginx-test
nginx-test
rollback: manually requested rollback
overall progress: rolling back update: 2 out of 2 tasks
1/2: running [> ]
2/2: running [> ]
verify: Service converged
查看服务，镜像已经更新成 nginx:latest
[root@swarm-master ~]# docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
k8r71cut7ofe nginx-test replicated 2/2 nginx:latest
[root@swarm-master ~]# docker service ps -f "desired-state=running" nginx-test
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
ayvu09m4yjuh nginx-test.1 nginx:latest swarm-master Running Running about a minute ago
kukxp1q8pmo7 nginx-test.2 nginx:latest swarm-node02 Running Running about a minute ago
8、排除节点
排除主节点
docker node update --availability drain swarm-master
查看任务，都运行在了node节点上
[root@swarm-master ~]# docker service ps -f "desired-state=running" nginx-test
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
kxvko9n3ct72 nginx-test.1 nginx:latest swarm-node02 Running Running 4 minutes ago
kukxp1q8pmo7 nginx-test.2 nginx:latest swarm-node02 Running Running 11 minutes ago
9、激活节点
docker node update --availability active swarm-master
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