搭建Dashboard时执行
kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.4/aio/deploy/recommended.yaml

查看pod状态，一直报错Pending

[root@master01 k8s]# kubectl get pods -n kubernetes-dashboard

NAME                                         READY   STATUS    RESTARTS   AGE
dashboard-metrics-scraper-6c9bfb459b-ldrfb   0/1     Pending   0          28m
kubernetes-dashboard-5947dc95db-n42cs        0/1     Pending   0          20m

查看pod的详细信息，发现报错调度错误：0/2 nodes are available: 2 node(s) didn’t match node selector

[root@master01 k8s]# kubectl describe pod kubernetes-dashboard-5947dc95db-n42cs -n kubernetes-dashboard
Name:               kubernetes-dashboard-5947dc95db-n42cs
Namespace:          kubernetes-dashboard
Priority:           0
PriorityClassName:  <none>
Node:               <none>
Labels:             k8s-app=kubernetes-dashboard
                    pod-template-hash=5947dc95db
Annotations:        <none>
Status:             Pending


Events:
  Type     Reason            Age                  From               Message
  ----     ------            ----                 ----               -------
  Warning  FailedScheduling  83s (x241 over 21m)  default-scheduler  0/2 nodes are available: 2 node(s) didn't match node selector.

原因：如果当前集群中没有一个node的label符合这个nodeSelector，就会报这个错误

解决方法：在yaml文件里面注释掉nodeSelector

重新启动dashboard，验证pod启动成功

[root@master01 k8s]# kubectl get pods -n kubernetes-dashboard
NAME                                         READY   STATUS    RESTARTS   AGE
dashboard-metrics-scraper-7f44bd8d8b-pqs75   1/1     Running   0          7s
kubernetes-dashboard-849796f7fd-9kfnm        1/1     Running   0          7s