Docker实践―CentOS7上部署Kubernetes详解

Docker  /  管理员 发布于 7年前   226

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 apiserverKUBE_MASTER="10.193.6.35:8080" # Comma seperated list of minionsMINION_ADDRESSES="10.193.6.36" # Port minions listen onMINION_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 clusterKUBE_ETCD_SERVERS="http://10.193.6.35:4001" # logging to stderr means we get it in the systemd journalKUBE_LOGTOSTDERR="true" # journal message level, 0 is debugKUBE_LOG_LEVEL=0 # Should this cluster be allowed to run privleged docker containersKUBE_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 $SERVICESdone

配置yy2

# cat /etc/kubernetes/kubelet#### kubernetes kublet (minion) config # The address for the info server to serve onMINION_ADDRESS="10.193.6.36" # The port for the info server to serve onMINION_PORT="10250"# You may leave this blank to use the actual hostnameMINION_HOSTNAME="10.193.6.36"# 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 clusterKUBE_ETCD_SERVERS="http://10.193.6.35:4001" # logging to stderr means we get it in the systemd journalKUBE_LOGTOSTDERR="true"# journal message level, 0 is debugKUBE_LOG_LEVEL=0# Should this cluster be allowed to run privleged docker containersKUBE_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

[Unit]Description=Kubernetes Kubelet#After=docker.socket cadvisor.serviceAfter=cadvisor.service#Requires=docker.socket cadvisor.serviceRequires=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 podsI0925 06:43:26.768122 09313 request.go:292] Waiting for completion of /operations/1ID         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，

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