Swarm管理分布式docker

作者：【吴业亮】云计算开发工程师
博客：http://blog.csdn.net/wylfengyujiancheng

在各个节点上

# yum -y install docker# systemctl start docker # systemctl enable docker

docker版本必须在v1.12以上，如果不是用 yum upgrade docker

# docker -v Docker version 1.12.6, build 96d83a5/1.12.6

禁用live-restore（各个节点）

 vi /etc/docker/daemon.json{    "live-restore": false}

重启服务（各个节点）

# systemctl restart docker

初始化管理节点（管理节点）

# docker swarm initSwarm initialized: current node (4ejgdnkv3ldew0ol6rpxrw1it) is now a manager.To add a worker to this swarm, run the following command:    docker swarm join \    --token SWMTKN-1-1fhqkce0ryjzthluf5lro4mesmfuuk2apbr8339e6ybu7sj4bx-27n8grtwz9aa0cpqr7crjz2ru \    192.168.10.226:2377To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

将work节点加入到Swarm Cluste中（work节点）

# docker swarm join \    --token SWMTKN-1-1fhqkce0ryjzthluf5lro4mesmfuuk2apbr8339e6ybu7sj4bx-27n8grtwz9aa0cpqr7crjz2ru \    192.168.10.226:2377

以下操作均在manager节点
验证各个节点已经加入集群中

# docker node lsID                           HOSTNAME            STATUS  AVAILABILITY  MANAGER STATUS4ejgdnkv3ldew0ol6rpxrw1it *  host-192-168-10-226  Ready   Active        Leader7xykqelamornqz4ovzzzw51yl    host-192-168-10-227  Ready   Activeebb3mnzguc94qycs6g3q8gy2y    host-192-168-10-228  Ready   Active

在各个节点上构建image
节点1上Dockerfile

FROM centosMAINTAINER serverworld <admin@cloud>RUN yum -y install httpdRUN echo "Hello DockerFile 1" > /var/www/html/index.htmlEXPOSE 80CMD ["-D", "FOREGROUND"]ENTRYPOINT ["/usr/sbin/httpd"]

# docker build -t web_server:latest .

节点2上Dockerfile

FROM centosMAINTAINER serverworld <admin@cloud>RUN yum -y install httpdRUN echo "Hello DockerFile 2 " > /var/www/html/index.htmlEXPOSE 80CMD ["-D", "FOREGROUND"]ENTRYPOINT ["/usr/sbin/httpd"]

# docker build -t web_server:latest .

节点3上Dockerfile

FROM centosMAINTAINER serverworld <admin@cloud>RUN yum -y install httpdRUN echo "Hello DockerFile 3 " > /var/www/html/index.htmlEXPOSE 80CMD ["-D", "FOREGROUND"]ENTRYPOINT ["/usr/sbin/httpd"]

# docker build -t web_server:latest .

在管理节点上创建负载均衡集群

# docker imagesREPOSITORY          TAG                 IMAGE ID            CREATED              SIZEweb_server          latest              18494cba819c        About a minute ago   318.4 MB

创建集群

# docker service create --name swarm_cluster --replicas=2 -p 80:80 web_server:latest20o5l3yrtssfi7au86s7t4m1f

查看集群

# docker service lsID            NAME           REPLICAS  IMAGE              COMMAND20o5l3yrtssf  swarm_cluster  0/2       web_server:latest

查看详细信息

# docker service inspect swarm_cluster --prettyID:             20o5l3yrtssfi7au86s7t4m1fName:           swarm_clusterMode:           Replicated Replicas:      2Placement:UpdateConfig: Parallelism:   1 On failure:    pauseContainerSpec: Image:         web_server:latestResources:Ports: Protocol = tcp TargetPort = 80 PublishedPort = 80

查看容器状态

#  docker service ps swarm_clusterID                         NAME                 IMAGE              NODE                DESIRED STATE  CURRENT STATE            ERRORabcz5de7owcw681mdmxwrce74  swarm_cluster.1      web_server:latest  host-192-168-10-227  Running        Running 26 seconds agoeuuvlsvo5fe1p79g49yo5yjrd  swarm_cluster.2      web_server:latest  host-192-168-10-228  Running        Running 12 seconds ago18tf6wzuc9zl5e3kkf822z17e   \_ swarm_cluster.2  web_server:latest  host-192-168-10-226  Shutdown       Rejected 32 seconds ago  "No such image: web_server:lat…"

测试

# curl http://192.168.10.226/Hello DockerFile 3[root@host-192-168-10-226 ~]# curl http://192.168.10.226/Hello DockerFile 2

更改集群的数量

#  docker service scale swarm_cluster=3

swarm_cluster scaled to 3

查看数量

# docker service ps swarm_clusterID                         NAME                 IMAGE              NODE                DESIRED STATE  CURRENT STATE             ERRORabcz5de7owcw681mdmxwrce74  swarm_cluster.1      web_server:latest  host-192-168-10-227  Running        Running 2 minutes agoeuuvlsvo5fe1p79g49yo5yjrd  swarm_cluster.2      web_server:latest  host-192-168-10-228  Running        Running 2 minutes ago18tf6wzuc9zl5e3kkf822z17e   \_ swarm_cluster.2  web_server:latest  host-192-168-10-226  Shutdown       Rejected 2 minutes ago    "No such image: web_server:lat…"5fb0cew9ih12wm4wioanm13up  swarm_cluster.3      web_server:latest  host-192-168-10-226  Running        Preparing 11 seconds ago