k8s入门系列之集群安装篇

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

配置阿里源安装epel-release

master：

[root@master ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

[root@master ~]# yum -y install epel-release

node1：

[root@node1 ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

[root@node1 ~]# yum -y install epel-release

node2：

[root@node:2 ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

[root@node2 ~]# yum -y install epel-release

node3：

[root@node:3 ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

[root@node3 ~]# yum -y install epel-release

node4：

[root@node:4 ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

[root@node4 ~]# 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。

master：

[root@master ~]# systemctl stop firewalld
[root@master~]# systemctl disable firewalld
[root@master~]# setenforce 0

node1：

[root@node1 ~]# systemctl stop firewalld
[root@node1 ~]# systemctl disable firewalld
[root@node1 ~]# setenforce 0

node2：

[root@node2 ~]# systemctl stop firewalld
[root@node2 ~]# systemctl disable firewalld
[root@node2 ~]# setenforce 0

node3：

[root@node3 ~]# systemctl stop firewalld
[root@node3 ~]# systemctl disable firewalld
[root@node3 ~]# setenforce 0

node4：

[root@node4 ~]# systemctl stop firewalld
[root@node4 ~]# systemctl disable firewalld
[root@node4 ~]# 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

[root@master ~]# yum -y install etcd kubernetes-master

2.编辑/etc/etcd/etcd.conf文件

[root@master ~]# vim /etc/etcd/etcd.conf

ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"   #修改此行
ETCD_NAME="default"
ETCD_ADVERTISE_CLIENT_URLS="http://172.25.1.25:2379"

3.编辑/etc/kubernetes/apiserver文件

[root@master ~]# vim /etc/kubernetes/apiserver

KUBE_API_ADDRESS="--insecure-bind-address=0.0.0.0"

KUBE_API_PORT="--port=8080"     #去掉注释#

KUBELET_PORT="--kubelet-port=10250"   #去掉注释#

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"         ##去掉此行中的“ServiceAccount”

KUBE_API_ARGS=""

4.启动etcd、kube-apiserver、kube-controller-manager、kube-scheduler等服务，并设置开机启动。

[root@master ~]# 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

[root@master ~]# etcdctl mk /atomic.io/network/config '{"Network":"172.17.0.0/16"}'
{"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

[root@node1 ~]# yum -y install flannel kubernetes-node

[root@node2 ~]# yum -y install flannel kubernetes-node

[root@node3 ~]# yum -y install flannel kubernetes-node

[root@node4 ~]# yum -y install flannel kubernetes-node

2.为flannel网络指定etcd服务，修改/etc/sysconfig/flanneld文件

[root@node1 ~]# vim /etc/sysconfig/flanneld

[root@node2 ~]# vim /etc/sysconfig/flanneld

[root@node3 ~]# vim /etc/sysconfig/flanneld

[root@node4 ~]# vim /etc/sysconfig/flanneld

FLANNEL_ETCD_ENDPOINTS="http://172.25.1.25:2379"     #flannel网络指定etcd服务
FLANNEL_ETCD_PREFIX="/atomic.io/network"

3.修改/etc/kubernetes/config文件

[root@node1 ~]# vim /etc/kubernetes/config

[root@node2 ~]# vim /etc/kubernetes/config

[root@node3 ~]# vim /etc/kubernetes/config

[root@node4 ~]# vim /etc/kubernetes/config

KUBE_LOGTOSTDERR="--logtostderr=true"
KUBE_LOG_LEVEL="--v=0"
KUBE_ALLOW_PRIV="--allow-privileged=false"
KUBE_MASTER="--master=http://172.25.1.25:8080"   ##指定etcd服务

4.按照如下内容修改对应node的配置文件/etc/kubernetes/kubelet

node1:

[root@node1 ~]# vim /etc/kubernetes/kubelet

KUBELET_ADDRESS="--address=0.0.0.0"     ##修改成允许所有访问
KUBELET_PORT="--port=10250"    #去掉注释#
KUBELET_HOSTNAME="--hostname-override=172.25.1.21"   #修改成对应Node的IP
KUBELET_API_SERVER="--api-servers=http://172.25.1.25:8080"    #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:

[root@node2 ~]# vim /etc/kubernetes/kubelet

KUBELET_ADDRESS="--address=0.0.0.0"     ##修改成允许所有访问
KUBELET_PORT="--port=10250"    #去掉注释#
KUBELET_HOSTNAME="--hostname-override=172.25.1.22"   #修改成对应Node的IP
KUBELET_API_SERVER="--api-servers=http://172.25.1.25:8080"    #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=""

node3:

[root@node3 ~]# vim /etc/kubernetes/kubelet

KUBELET_ADDRESS="--address=0.0.0.0"     ##修改成允许所有访问
KUBELET_PORT="--port=10250"    #去掉注释#
KUBELET_HOSTNAME="--hostname-override=172.25.1.21"   #修改成对应Node的IP
KUBELET_API_SERVER="--api-servers=http://172.25.1.25:8080"    #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=""

node4:

[root@node4 ~]# vim /etc/kubernetes/kubelet

KUBELET_ADDRESS="--address=0.0.0.0"     ##修改成允许所有访问
KUBELET_PORT="--port=10250"    #去掉注释#
KUBELET_HOSTNAME="--hostname-override=172.25.1.21"   #修改成对应Node的IP
KUBELET_API_SERVER="--api-servers=http://172.25.1.25:8080"    #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=""

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。

[root@node1 ~]# for SERVICES in kube-proxy kubelet docker flanneld;do systemctl restart $SERVICES;systemctl enable $SERVICES;systemctl status $SERVICES; done

[root@node2 ~]# for SERVICES in kube-proxy kubelet docker flanneld;do systemctl restart $SERVICES;systemctl enable $SERVICES;systemctl status $SERVICES; done

[root@node3 ~]# for SERVICES in kube-proxy kubelet docker flanneld;do systemctl restart $SERVICES;systemctl enable $SERVICES;systemctl status $SERVICES; done

[root@node4 ~]# 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

[root@master ~]# kubectl get node
NAME STATUS AGE
172.25.1.21 Ready 1m
172.25.1.22 Ready 1m
172.25.1.23 Ready 1m
172.25.1.24 Ready 1m