在实际生产环境中，往往需要维护多个k8s集群，在多个环境和节点之间切换，影响工作效率，不符合devops的理念，因此尝试在单个节点下面维护多个k8s集群。
1) 模拟存在两套k8s集群
第一个k8s集群：
[root@k8smaster ~]# kubectl get nodes NAME STATUS ROLES VERSION k8smaster Ready controlplane v1.23.1 k8slave Ready worker v1.23.1 k8smaster：182.168.40.180 k8slave：192.168.40.181
第二个k8s集群
[root@k8smaster2]# kubectl get nodes NAME STATUS ROLES VERSION k8smaster2 Ready controlplane v1.23.1 k8slave2 Ready worker v1.23.1 k8smaster2：192.168.40.185 k8slave2： 192.168.40.186
2) kubeconfig文件
查看kubeconfig文件可以使用kubectl config命令,也可以直接查看/root/.kube/config（默认位置）
k8smaster集群 [root@k8smaster ~]#kubectl config view apiVersion: v1 clusters: - cluster: certificate-authority-data: DATA+OMITTED server: https://192.168.40.180:6443 name: kubernetes contexts: - context: cluster: kubernetes user: kubernetes-admin name: kubernetes-admin@kubernetes current-context:kubernetes-admin@kubernetes kind: Config preferences: {} users: - name:kubernetes-admin user: client-certificate-data: REDACTED client-key-data: REDACTED
k8smaster2集群
[root@k8smaster2~]# kubectl config view apiVersion: v1 clusters: - cluster: certificate-authority-data: DATA+OMITTED server: https://192.168.40.185:6443 name: kubernetes contexts: - context: cluster: kubernetes user: kubernetes-admin name: kubernetes-admin@kubernetes current-context:kubernetes-admin@kubernetes kind: Config preferences: {} users: - name:kubernetes-admin user: client-certificate-data: REDACTED client-key-data: REDACTED
3) 在k8smaster上配置k8smaster2的cluster、user、context
a、添加cluster
[root@k8smaster]#kubectl config set-cluster k8smaster2 --server=https://192.168.40.185:6443--insecure-skip-tls-verify=true
b、添加user
[root@k8smaster]#kubeadm token create --print-join-command [root@k8smaster]#kubectl config set-credentials k8smaster2-user --token= clknqa.km25oi82urcuja9u
c、添加context
[root@k8smaster]# kubectl config set-context k8smaster2-context--cluster= k8smaster2 --user=k8smaster2-user
d、切换context管理k8s集群
[root@k8smaster]#kubectl config use-context k8smaster2-context
至此，在k8smaster节点上维护了两个k8s集群，按照同样的办法可以添加更多的k8s集群，只是通过不同的context进行切换。
