k8s环境搭建（二）——初始化集群

1. 前言

接上一篇文章：https://blog.csdn.net/weixin_29003023/article/details/110409382，不过这篇文章写的不是很好，还需要改善下。
本文假定你已经安装docker，kubelet、kubeadm、kubectl。

2. 初始化master节点

所有机器添加master域名映射。给/etc/hosts文件配置主节点的IP，例如如下：10.206.0.9为主节点的内外IP。

echo "10.206.0.9  cluster-endpoint" >> /etc/hosts

主节点初始化

kubeadm init \
--apiserver-advertise-address=10.206.0.9 \
--control-plane-endpoint=cluster-endpoint \
--image-repository registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images \
--kubernetes-version v1.20.9 \
--service-cidr=10.96.0.0/16 \
--pod-network-cidr=192.168.0.0/16

初始化结果：

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

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

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/

You can now join any number of control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:

  kubeadm join cluster-endpoint:6443 --token zkm0a3.pgvodwj1bn26lj9h \
    --discovery-token-ca-cert-hash sha256:85aed272ede53d8a84c75a173c35c44727734c9c29de3e16eaeb1a936bb84546 \
    --control-plane 

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

kubeadm join cluster-endpoint:6443 --token zkm0a3.pgvodwj1bn26lj9h \
    --discovery-token-ca-cert-hash sha256:85aed272ede53d8a84c75a173c35c44727734c9c29de3e16eaeb1a936bb84546

3. 开启主节点

根据上面的初始化结果输出，开启主节点：

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

以上这几条命令，再上面的初始化结果中寻找哈。
查看主节点初始化结果：

[root@VM-0-9-centos ~]# kubectl get nodes
NAME            STATUS     ROLES                  AGE    VERSION
vm-0-9-centos   NotReady   control-plane,master   6m4s   v1.20.9
[root@VM-0-9-centos ~]# 

4. 安装网络插件

安装的是calico这个网络组件。

[root@VM-0-9-centos ~]# curl https://docs.projectcalico.org/manifests/calico.yaml -O
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  212k  100  212k    0     0   2752      0  0:01:19  0:01:19 --:--:--  4651
[root@VM-0-9-centos ~]# ls
calico.yaml  images.sh
[root@VM-0-9-centos ~]# kubectl apply -f calico.yaml 
configmap/calico-config created
customresourcedefinition.apiextensions.k8s.io/bgpconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/bgppeers.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/blockaffinities.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/caliconodestatuses.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/clusterinformations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/felixconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/globalnetworkpolicies.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/globalnetworksets.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/hostendpoints.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamblocks.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamconfigs.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamhandles.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ippools.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipreservations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/kubecontrollersconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/networkpolicies.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/networksets.crd.projectcalico.org created
clusterrole.rbac.authorization.k8s.io/calico-kube-controllers created
clusterrolebinding.rbac.authorization.k8s.io/calico-kube-controllers created
clusterrole.rbac.authorization.k8s.io/calico-node created
clusterrolebinding.rbac.authorization.k8s.io/calico-node created
daemonset.apps/calico-node created
serviceaccount/calico-node created
deployment.apps/calico-kube-controllers created
serviceaccount/calico-kube-controllers created
poddisruptionbudget.policy/calico-kube-controllers created

检查主节点状态：

[root@VM-0-9-centos ~]# kubectl get nodes
NAME            STATUS   ROLES                  AGE   VERSION
vm-0-9-centos   Ready    control-plane,master   52m   v1.20.9
[root@VM-0-9-centos ~]# 

5. 加入node节点

kubeadm join cluster-endpoint:6443 --token zkm0a3.pgvodwj1bn26lj9h \
>     --discovery-token-ca-cert-hash sha256:85aed272ede53d8a84c75a173c35c44727734c9c29de3e16eaeb1a936bb84546

加入之后，在主节点上查看集群：