k8s的搭建和简单使用

环境

三台centos7系统
192.168.72.128 master
192.168.72.129 node1
192.168.72.132 node2

master和node节点上的操作

	1 时间同步
		ntpdate pool.ntp.date
	2 关闭防火前和selinux
		systemctl stop firewalld
		setenforce 0
	3 更改主机名称
		hostname master(master上操作)
		hostname node1(node1上操作)
		hostname node2(node2上操作)
	4 更改 /etc/hosts文件(每个机器都得做,内容一样)
		vim /etc/hosts/
		192.168.72.128 master
		192.168.72.129 node1
		192.168.72.132 node2
	5 安装docker
		上传docker.repo或者
		yum -y install yum-utils device-mapper-persistent-data lvm2
		yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo 然后再进行安装
		安装指定版本
		yum -y install docker-ce-18.09.7 docker-ce-cli-18.09.7 containerd.io
		查看版本 docker --version
		启动并设置开机自启
		systemctl start docker
		sysetmctl enable docker
		设置加速
		vim /etc/docker/daemon.json
			{
   
   
  			"exec-opts": ["native.cgroupdriver=systemd"]
			}
		重启docker systemctl restart docker
		docker info |grep Cgroup
			Cgroup Driver: systemd
	6 安装kubeadm
		(1)配置kubenetes的yum仓库（这里使用阿里云仓库）
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-	x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
        	https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF



# yum makecache
		(2)安装kubelat、kubectl、kubeadm
			yum -y install kubelet-1.15.2 kubeadm-1.15.2 kubectl-1.15.2
			查看安装是否成功 rpm -aq kubelet kubectl kubeadm
				kubectl-1.15.2-0.x86_64
				kubelet-1.15.2-0.x86_64
				kubeadm-1.15.2-0.x86_64
		(3)将kubelet加入开机启动，
		   这里刚安装完成不能直接启动。（因为目前还没有集群还没有建立）
			 systemctl enable kubelet

初始化Master(在master节点执行)

通过kubeadm --help帮助手册，可以看到可以通过kubeadm init初始化一个master节点
，然后再通过kubeadm join将一个node节点加入到集群中。
[root@master ~]# cat /etc/sysconfig/kubelet 
	KUBELET_EXTRA_ARGS="--fail-swap-on=false"


## 开始进行初始化
[root@master ~]# kubeadm init --kubernetes-version=v1.15.2 --image-repository registry.aliyuncs.com/google_containers --pod-network-cidr=10.244.0.0/16 --service-cidr=10.96.0.0/12 --ignore-preflight-errors=Swap

		......
	Your Kubernetes control-plane has initialized successfully!

	To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 192.168.72.128:6443 --token damed3.0ow9o2c5sbw4xa3d \
    --discovery-token-ca-cert-hash sha256:6609879475365b92ee1d98d2cf187ff4add2e6ae9e0b3eed869036cb51ff17ce 
看到此界面,初始化成功,开始进行下一步操作


操作都可已在上边的初始化结果中找到,直接复制粘贴即可
  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config
 [root@master ~]# docker image ls   #初始化完成后可以看到所需镜像也拉取下来了
	 	REPOSITORY                                                        TAG                 					IMAGE ID            CREATED             SIZE
	registry.aliyuncs.com/google_containers/kube-apiserver            v1.15.2             34a53be6c9a7        15 months ago       207MB
	registry.aliyuncs.com/google_containers/kube-controller-manager   v1.15.2             9f5df470155d        15 months ago       159MB
	registry.aliyuncs.com/google_containers/kube-scheduler            v1.15.2             88fa9cb27bd2        15 months ago       81.1MB
	registry.aliyuncs.com/google_containers/kube-proxy                v1.15.2             167bbf6c9338        15 months ago       82.4MB
	registry.aliyuncs.com/google_containers/coredns                   1.3.1               eb516548c180        22 months ago       40.3MB
	registry.aliyuncs.com/google_containers/etcd                      3.3.10              2c4adeb21b4f        23 months ago       258MB
	registry.aliyuncs.com/google_containers/pause                     3.1                 da86e6ba6ca1        2 years ago         742kB


添加flannel网络组件,把kube-flannel.yml文件放到/root目录下
kubectl apply -f  kube-flannel.yml

//验证flannel网络插件是否部署成功（Running即为成功）
[root@master ~]# kubectl get pods -n kube-system |grep flannel
kube-flannel-ds-765qc            1/1     Running   0          2m34s
	

加入node节点

向集群中添加新节点，执行在kubeadm init 输出的
kubeadm join命令，再在后面同样添加忽略swap报错参数。
1)配置忽略swap报错
[root@node1 ~]# vim /etc/sysconfig/kubelet
KUBELET_EXTRA_ARGS="--fail-swap-on=false"

[root@node2 ~]# vim /etc/sysconfig/kubelet
KUBELET_EXTRA_ARGS="--fail-swap-on=false"
2)加入node1节点
kubeadm join 192.168.72.128:6443 --token damed3.0ow9o2c5sbw4xa3d \
    --discovery-token-ca-cert-hash sha256:6609879475365b92ee1d98d2cf187ff4add2e6ae9e0b3eed869036cb51ff17ce 
(master初始化中的内容直接复制过来)



   [preflight] Running pre-flight checks
    [WARNING Swap]: running with swap on is not supported. Please disable swap
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubele