k8s入门系列之集群安装篇
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Kubernetes集群安装部署
•Kubernetes集群组件:
- etcd 一个高可用的K/V键值对存储和服务发现系统
- flannel 实现夸主机的容器网络的通信
- kube-apiserver 提供kubernetes集群的API调用
- kube-controller-manager 确保集群服务
- kube-scheduler 调度容器，分配到Node
- kubelet 在Node节点上按照配置文件中定义的容器规格启动容器
- kube-proxy 提供网络代理服务
•集群示意图
Kubernetes工作模式server-client，Kubenetes Master提供集中化管理Minions。部署1台Kubernetes Master节点和4台Minion节点，
示意图如下:
•先决条件
如下操作在所有机器执行
1.确保系统已经安装epel-release源
# yum -y install epel-release
2.关闭防火墙服务和selinx，避免与docker容器的防火墙规则冲突。
# systemctl stop firewalld
# systemctl disable firewalld
# setenforce 0
•安装配置Kubernetes Master
如下操作在master上执行
1.使用yum安装etcd和kubernetes-master
# yum -y install etcd kubernetes-master
2.编辑/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.编辑/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.启动etcd、kube-apiserver、kube-controller-manager、kube-scheduler等服务，并设置开机启动。
# 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中定义flannel网络
# etcdctl mk /atomic.io/network/config '{"Network":"172.17.0.0/16"}'
•安装配置Kubernetes Node
如下操作在node1、node2、node3、node4上执行
1.使用yum安装flannel和kubernetes-node
# yum -y install flannel kubernetes-node
2.为flannel网络指定etcd服务，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.按照如下内容修改对应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" #修改成对应Node的IP KUBELET_API_SERVER="--api-servers=http://192.168.30.20:8080" #指定Master节点的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节点上启动kube-proxy,kubelet,docker,flanneld等服务，并设置开机启动。
# for SERVICES in kube-proxy kubelet docker flanneld;do systemctl restart $SERVICES;systemctl enable $SERVICES;systemctl status $SERVICES; done
•验证集群是否安装成功
在master上执行如下命令
[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
*注释:上述4个节点正常显示，状态为Ready，则说明集群搭建成功，至于集群的应用会在后续文章中介绍。
