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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