關於kubernetes組件的詳解介紹，請閱讀上一篇文章《k8s入門系列之介紹篇》
Kubernetes集群安裝部署
•Kubernetes集群組件:
- etcd 一個高可用的K/V鍵值對存儲和服務發現系統
- flannel 實現誇主機的容器網絡的通信
- kube-apiserver 提供kubernetes集群的API調用
- kube-controller-manager 確保集群服務
- kube-scheduler 調度容器，分配到Node
- kubelet 在Node節點上按照配置文件中定義的容器規格啟動容器
- kube-proxy 提供網絡代理服務
•集群示意圖
Kubernetes工作模式server-client，Kubenetes Master提供集中化管理Minions。部署1台Kubernetes Master節點和4台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.關閉防火牆服務和selinx，避免與docker容器的防火牆規則沖突。
# systemctl stop firewalld
# systemctl disable firewalld
# setenforce 0
•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文件
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文件
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，並設置開機啟動。
# 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網絡
# 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網絡指定etcd服務，修改/etc/sysconfig/flanneld文件
FLANNEL_ETCD="http://192.168.30.20:2379" FLANNEL_ETCD_KEY="/atomic.io/network"
3.修改/etc/kubernetes/config文件
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的配置文件/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，並設置開機啟動。
# for SERVICES in kube-proxy kubelet docker flanneld;do systemctl restart $SERVICES;systemctl enable $SERVICES;systemctl status $SERVICES; done
•驗證集群是否安裝成功
在master上執行如下命令
[root@master ~]# 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
*注釋:上述4個節點正常顯示，狀態為Ready，則說明集群搭建成功，至於集群的應用會在后續文章中介紹。