Docker實踐(6)—CentOS7上部署Kubernetes

YY哥發表於2014-09-25
DockerCentOS

Kubernetes架構

Kubernetes的整體架構如下：

 NewImage

Master為主控節點，上面執行apiserver，scheduler，controller-manager等元件。Minion相當於工作節點，上面執行kubelet，proxy，cAdvisor以及最重要的docker等元件。下面來實際部署一下這套叢集管理工具。

環境

yy1  10.193.6.35

yy2  10.193.6.36

yy1作為master，yy2作為minion。

 

# cat /etc/centos-release

CentOS Linux release 7.0.1406 (Core)

 

安裝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"

 

 

啟動yy1上相關服務

master上需要執行etcd，kube-apiserver，kube-controller-manager，kube-scheduler這4個程式。

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上沒有docker.socket服務，註釋掉kubelet中對docker.socket的依賴。

/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

 

 

啟動yy2上的相關服務

minion上需要執行kube-proxy，kubelet以及docker。

for SERVICES in kube-proxy kubelet docker; do 
    systemctl restart $SERVICES
    systemctl enable $SERVICES
    systemctl status $SERVICES 
done

 

建立pod描述檔案

建立一個apache的pod描述檔案。

# 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"

  }

}

 

 

建立pod

通過客戶端工具kubecfg提交任務給apiserver，由scheduler選擇一個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服務會自動部署到機器yy2，yy2上的docker會自動下載image，然後啟動apache服務。順利的話，過一會兒，apache服務就會在yy2上起來。

[root@yy1 ~]# kubecfg list pods  

ID                  Image(s)            Host                Labels              Status

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

apache              fedora/apache       10.193.6.36/        name=apache         Running

 

 NewImage

可以嘗試訪問一下，

 NewImage

 

主要參考

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


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