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

注释掉以后重新启动dashboard还是报错，这次报错error

[root@master01 k8s]# kubectl get pods -n kubernetes-dashboard
NAME                                         READY   STATUS    RESTARTS   AGE
dashboard-metrics-scraper-7f44bd8d8b-d4cwl   1/1     Running   0          2m24s
kubernetes-dashboard-786df6b6b8-7pfdk        0/1     Error     1          2m24s

查看pod详细信息，报错：Back-off restarting failed container

[root@master01 k8s]# kubectl describe pod kubernetes-dashboard-786df6b6b8-7pfdk -n kubernetes-dashboard
Name:               kubernetes-dashboard-786df6b6b8-7pfdk
Namespace:          kubernetes-dashboard
Priority:           0
PriorityClassName:  <none>
Node:               192.168.245.210/192.168.245.210
Start Time:         Thu, 08 Oct 2020 17:30:40 +0800
Labels:             k8s-app=kubernetes-dashboard
                    pod-template-hash=786df6b6b8
Annotations:        <none>
Status:             Running
IP:                 172.17.75.2
Controlled By:      ReplicaSet/kubernetes-dashboard-786df6b6b8
Containers:
  kubernetes-dashboard:
    Container ID:  docker://4b2497125a5b8b09a00cf5496ead7752085e2879b33530fdf4693d3569c41a05
    Image:         kubernetesui/dashboard:v2.0.4
    Image ID:      docker-pullable://kubernetesui/dashboard@sha256:c557b14b678739c91cb5e7874f47dc6a2c160749aa0cb750217d94e10481b511
    Port:          8443/TCP
    Host Port:     0/TCP

Events:
  Type     Reason     Age                  From                      Message
  ----     ------     ----                 ----                      -------
  Normal   Scheduled  3m33s                default-scheduler         Successfully assigned kubernetes-dashboard/kubernetes-dashboard-786df6b6b8-7pfdk to 192.168.245.210
  Normal   Pulling    51s (x3 over 3m32s)  kubelet, 192.168.245.210  pulling image "kubernetesui/dashboard:v2.0.4"
  Normal   Pulled     40s (x3 over 2m13s)  kubelet, 192.168.245.210  Successfully pulled image "kubernetesui/dashboard:v2.0.4"
  Normal   Created    40s (x3 over 2m13s)  kubelet, 192.168.245.210  Created container
  Normal   Started    39s (x3 over 2m13s)  kubelet, 192.168.245.210  Started container
  Warning  BackOff    3s (x5 over 73s)     kubelet, 192.168.245.210  Back-off restarting failed container

解决方法：在yaml文件中注释总是拉取镜像的配置

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