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Kubernetes叢集安裝部署

•Kubernetes叢集元件:
　　- etcd 一個高可用的K/V鍵值對儲存和服務發現系統
　　- flannel 實現誇主機的容器網路的通訊
　　- kube-apiserver 提供kubernetes叢集的API呼叫
　　- kube-controller-manager 確保叢集服務
　　- kube-scheduler 排程容器，分配到Node
　　- kubelet 在Node節點上按照配置檔案中定義的容器規格啟動容器
　　- kube-proxy 提供網路代理服務

•叢集示意圖
　　Kubernetes工作模式server-client，Kubenetes Master提供集中化管理Minions。部署1臺Kubernetes Master節點和4臺Minion節點，
　示意圖如下:

•先決條件

如下操作在所有機器執行

1.確保系統已經安裝epel-release源

# yum -y install epel-release

2.關閉防火牆服務，避免與docker容器的防火牆規則衝突。

# systemctl stop firewalld
# systemctl disable firewalld

•安裝配置Kubernetes Master
如下操作在master上執行
1.使用yum安裝etcd和kubernetes-master

# yum -y install etcd kubernetes-master

2.編輯/etc/etcd/etcd.conf檔案

ETCD_NAME=default
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
ETCD_ADVERTISE_CLIENT_URLS="http://localhost:2379"

3.編輯/etc/kubernetes/apiserver檔案

KUBE_API_ADDRESS="--insecure-bind-address=0.0.0.0"
KUBE_API_PORT
 
="--port=8080"
KUBELET_PORT="--kubelet-port=10250"
KUBE_ETCD_SERVERS="--etcd-servers=http://127.0.0.1:2379"
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"
KUBE_API_ARGS=""

4.啟動etcd、kube-apiserver、kube-controller-manager、kube-scheduler等服務，並設定開機啟動。

# for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler; do systemctl restart $SERVICES;systemctl enable $SERVICES;systemctl status $SERVICES ; done

5.在etcd中定義flannel網路

# etcdctl mk /atomic.io/network/config '{"Network":"172.17.0.0/16"}'

•安裝配置Kubernetes Node
如下操作在node1、node2、node3、node4上執行
1.使用yum安裝flannel和kubernetes-node

# yum -y install flannel kubernetes-node

2.為flannel網路指定etcd服務，修改/etc/sysconfig/flanneld檔案

FLANNEL_ETCD="http://192.168.30.20:2379"
FLANNEL_ETCD_KEY="/atomic.io/network"

3.修改/etc/kubernetes/config檔案

KUBE_LOGTOSTDERR="--logtostderr=true"
KUBE_LOG_LEVEL="--v=0"
KUBE_ALLOW_PRIV="--allow-privileged=false"
KUBE_MASTER="--master=http://192.168.30.20:8080"

4.按照如下內容修改對應node的配置檔案/etc/kubernetes/kubelet

node1:

KUBELET_ADDRESS="--address=0.0.0.0"
KUBELET_PORT="--port=10250"
KUBELET_HOSTNAME="--hostname-override=192.168.30.21" #修改成對應Node的IP
KUBELET_API_SERVER="--api-servers=http://192.168.30.20:8080" #指定Master節點的API Server
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"
KUBELET_ARGS=""

node2:

KUBELET_ADDRESS="--address=0.0.0.0"
KUBELET_PORT="--port=10250"
KUBELET_HOSTNAME="--hostname-override=192.168.30.22" 
KUBELET_API_SERVER="--api-servers=http://192.168.30.20:8080"
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"
KUBELET_ARGS=""

node3:

KUBELET_ADDRESS="--address=0.0.0.0"
KUBELET_PORT="--port=10250"
KUBELET_HOSTNAME="--hostname-override=192.168.30.23"
KUBELET_API_SERVER="--api-servers=http://192.168.30.20:8080"
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"
KUBELET_ARGS=""

node4:

KUBELET_ADDRESS="--address=0.0.0.0"
KUBELET_PORT="--port=10250"
KUBELET_HOSTNAME="--hostname-override=192.168.30.24"
KUBELET_API_SERVER="--api-servers=http://192.168.30.20:8080"
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"
KUBELET_ARGS=""

5.在所有Node節點上啟動kube-proxy,kubelet,docker,flanneld等服務，並設定開機啟動。

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

•驗證叢集是否安裝成功
在master上執行如下命令

[[email protected] ~]# kubectl get node
NAME            STATUS    AGE
192.168.30.21   Ready     1m
192.168.30.22   Ready     1m
192.168.30.23   Ready     1m
192.168.30.24   Ready     1m

*註釋:上述4個節點正常顯示，狀態為Ready，則說明叢集搭建成功，至於叢集的應用會在後續文章中介紹。