Docker实践(6)—CentOS7上部署Kubernetes

Kubernetes架构

Kubernetes的整体架构如下：

 

Master为主控节点，上面运行apiserver，scheduler，controller-manager等组件。Minion相当于工作节点，上面运行kubelet，proxy，cAdvisor以及最重要的docker等组件。下面来实际部署一下这套集群管理工具。

环境

yy1  10.193.6.35

yy2  10.193.6.36

yy1作为master，yy2作为minion。

 

# cat /etc/centos-release

CentOS Linux release 7.0.1406 (Core)

 

安装kubernetes

# curl https://copr.fedoraproject.org/coprs/eparis/kubernetes-epel-7/repo/epel-7/eparis-kubernetes-epel-7-epel-7.repo -o /etc/yum.repos.d/eparis-kubernetes-epel-7-epel-7.repo



# yum install kubernetes -y

 

配置yy1

# cat /etc/kubernetes/apiserver



###



# kubernetes system config



#



# The following values are used to configure the kubernetes-apiserver



#



 



# The address on the local server to listen to.



KUBE_API_ADDRESS="10.193.6.35"



 



# The port on the local server to listen on.



KUBE_API_PORT="8080"



 



# How the replication controller and scheduler find the apiserver



KUBE_MASTER="10.193.6.35:8080"



 



# Comma seperated list of minions



MINION_ADDRESSES="10.193.6.36"



 



# Port minions listen on



MINION_PORT="10250"



 



# cat /etc/kubernetes/config



###



# kubernetes system config



#



# The following values are used to configure various aspects of all



# kubernetes services, including



#



#   kubernetes-apiserver.service



#   kubernetes-controller-manager.service



#   kubernetes-kubelet.service



#   kubernetes-proxy.service



 



# Comma seperated list of nodes in the etcd cluster



KUBE_ETCD_SERVERS="http://10.193.6.35:4001"



 



# logging to stderr means we get it in the systemd journal



KUBE_LOGTOSTDERR="true"



 



# journal message level, 0 is debug



KUBE_LOG_LEVEL=0



 



# Should this cluster be allowed to run privleged docker containers



KUBE_ALLOW_PRIV="true"

 

 

启动yy1上相关服务

master上需要运行etcd，kube-apiserver，kube-controller-manager，kube-scheduler这4个进程。

for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler; do



    systemctl restart $SERVICES



    systemctl enable $SERVICES



    systemctl status $SERVICES



done

 

 

配置yy2

 1 # cat /etc/kubernetes/kubelet

 2 

 3 ###

 4 

 5 # kubernetes kublet (minion) config

 6 

 7  

 8 

 9 # The address for the info server to serve on

10 

11 MINION_ADDRESS="10.193.6.36"

12 

13  

14 

15 # The port for the info server to serve on

16 

17 MINION_PORT="10250"

18 

19  

20 

21 # You may leave this blank to use the actual hostname

22 

23 MINION_HOSTNAME="10.193.6.36"

24 

25  

26 

27 # cat /etc/kubernetes/config  

28 

29 ###

30 

31 # kubernetes system config

32 

33 #

34 

35 # The following values are used to configure various aspects of all

36 

37 # kubernetes services, including

38 

39 #

40 

41 #   kubernetes-apiserver.service

42 

43 #   kubernetes-controller-manager.service

44 

45 #   kubernetes-kubelet.service

46 

47 #   kubernetes-proxy.service

48 

49  

50 

51 # Comma seperated list of nodes in the etcd cluster

52 

53 KUBE_ETCD_SERVERS="http://10.193.6.35:4001"

54 

55  

56 

57 # logging to stderr means we get it in the systemd journal

58 

59 KUBE_LOGTOSTDERR="true"

60 

61  

62 

63 # journal message level, 0 is debug

64 

65 KUBE_LOG_LEVEL=0

66 

67  

68 

69 # Should this cluster be allowed to run privleged docker containers

70 

71 KUBE_ALLOW_PRIV="true"

 

 

修改yy2 kubelet的配置

CentOS7上没有docker.socket服务，注释掉kubelet中对docker.socket的依赖。

/usr/lib/systemd/system/kubelet.service

 1  [Unit]

 2 

 3 Description=Kubernetes Kubelet

 4 

 5 #After=docker.socket cadvisor.service

 6 

 7 After=cadvisor.service

 8 

 9 #Requires=docker.socket cadvisor.service

10 

11 Requires=cadvisor.service

 

 

启动yy2上的相关服务

minion上需要运行kube-proxy，kubelet以及docker。

for SERVICES in kube-proxy kubelet docker; do 

    systemctl restart $SERVICES

    systemctl enable $SERVICES

    systemctl status $SERVICES 

done

 

创建pod描述文件

创建一个apache的pod描述文件。

# cat apache.json



{



  "id": "apache",



  "desiredState": {



    "manifest": {



      "version": "v1beta1",



      "id": "apache-1",



      "containers": [{



        "name": "master",



        "image": "fedora/apache",



        "ports": [{



          "containerPort": 80,



          "hostPort": 80



        }]



      }]



    }



  },



  "labels": {



    "name": "apache"



  }



}

 

 

创建pod

通过客户端工具kubecfg提交任务给apiserver，由scheduler选择一个minion部署容。

[root@yy1 ~]# kubecfg -c apache.json create pods



I0925 06:43:26.768122 09313 request.go:292] Waiting for completion of /operations/1



ID                  Image(s)            Host                Labels              Status



----------          ----------          ----------          ----------          ----------



apache              fedora/apache       /                   name=apache         Waiting



 



[root@yy1 ~]# kubecfg list pods 



ID                  Image(s)            Host                Labels              Status



----------          ----------          ----------          ----------          ----------



apache              fedora/apache       10.193.6.36/        name=apache         Waiting

 

 

apache服务会自动部署到机器yy2，yy2上的docker会自动下载image，然后启动apache服务。顺利的话，过一会儿，apache服务就会在yy2上起来。

[root@yy1 ~]# kubecfg list pods  



ID                  Image(s)            Host                Labels              Status



----------          ----------          ----------          ----------          ----------



apache              fedora/apache       10.193.6.36/        name=apache         Running

 

 

可以尝试访问一下，

 

 

主要参考

https://github.com/GoogleCloudPlatform/kubernetes/blob/master/docs/getting-started-guides/fedora/fedora_manual_config.md

作者：YY哥 
出处：http://www.cnblogs.com/hustcat/ 
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