Kubernetes dashboard status-CrashLoopBackOff

Question

I’m trying to implement Kubernetes dashboard and its status is always CrashLoopBackOff

host-xxx:~ # kubectl get pods --all-namespaces                                                                                                                                                                           
NAMESPACE     NAME                                    READY     STATUS             RESTARTS   AGE
default       locust-master-pr59t                     1/1       Running            0          2d
default       my-nginx-2565190728-8z0eh               1/1       Running            0          2d
default       my-nginx-2565190728-if4my               1/1       Running            0          2d
kube-system   kubernetes-dashboard-1975554030-80rxv   0/1       CrashLoopBackOff   249 

This is my yaml file:

host-xxx:~ # kubectl describe pod --namespace=kube-system kubernetes-dashboard-1975554030-80rxv
Name:           kubernetes-dashboard-1975554030-80rxv
Namespace:      kube-system
Node:           host-44-11-1-25/44.11.1.25
Start Time:     Wed, 21 Dec 2016 14:49:48 +0000
Labels:         app=kubernetes-dashboard
                pod-template-hash=1975554030
Status:         Running
IP:             172.20.140.2
Controllers:    ReplicaSet/kubernetes-dashboard-1975554030
Containers:
  kubernetes-dashboard:
    Container ID:               docker://708aac5cebdff057b69cec94e582cb45f7dba424c336fb320dd0d5e3243fc323
    Image:                      gcr.io/google_containers/kubernetes-dashboard-amd64:v1.5.0
    Image ID:                   docker://sha256:e5133bac8024ac6c916f16df8790259b5504a800766bee87dcf90ec7d634a418
    Port:                       9090/TCP
    State:                      Waiting
      Reason:                   CrashLoopBackOff
    Last State:                 Terminated
      Reason:                   Error
      Exit Code:                1
      Started:                  Thu, 22 Dec 2016 11:32:12 +0000
      Finished:                 Thu, 22 Dec 2016 11:32:13 +0000
    Ready:                      False
    Restart Count:              244
    Liveness:                   http-get http://:9090/ delay=30s timeout=30s period=10s #success=1 #failure=3
    Environment Variables:      <none>
Conditions:
  Type          Status
  Initialized   True
  Ready         False
  PodScheduled  True
No volumes.
QoS Tier:       BestEffort
Events:
  FirstSeen     LastSeen        Count   From                            SubobjectPath                           Type            Reason                  Message
  ---------     --------        -----   ----                            -------------                           --------        ------                  -------
  20h           3m              245     {kubelet host-44-11-1-25}       spec.containers{kubernetes-dashboard}   Normal          Pulling                 pulling image "gcr.io/google_containers/kubernetes-dashboard-amd64:v1.5.0"
  20h           3m              246     {kubelet host-44-11-1-25}                                               Warning         MissingClusterDNS       kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
  20h           3m              245     {kubelet host-44-11-1-25}       spec.containers{kubernetes-dashboard}   Normal          Pulled                  Successfully pulled image "gcr.io/google_containers/kubernetes-dashboard-amd64:v1.5.0"
  20h           3m              236     {kubelet host-44-11-1-25}       spec.containers{kubernetes-dashboard}   Normal          Created                 (events with common reason combined)
  20h           3m              236     {kubelet host-44-11-1-25}       spec.containers{kubernetes-dashboard}   Normal          Started                 (events with common reason combined)
  20h           3s              5940    {kubelet host-44-11-1-25}       spec.containers{kubernetes-dashboard}   Warning         BackOff                 Back-off restarting failed docker container
  20h           3s              5906    {kubelet host-44-11-1-25}   

Whats the issue?

Answer 1

You could use command
kubectl logs --namespace=kube-system kubernetes-dashboard-1975554030-80rxv
to check error details about what happened.
You might get this error or warning saying
 kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
Maybe you did not enable kubedns component yet, which may cause this problem.

to create your kubernetes dashboard, you could run command
kubectl edit pod kubernetes-dashboard-1975554030-80rxv -n kube-system
to manually change DNS policy to default. The key should be spec.template.spec.dnsPolicy to Default then recreate this Pod to see if it will work.

Level up your Kubernetes expertise with our industry-leading Kubernetes Course.

Answer 2

I had the same issue, I solved it by manually pointing to apiserver using the 'args' attribute in kubernetes-dashboard.yaml

args:
# Uncomment the following line to manually specify Kubernetes API server Host
# If not specified, Dashboard will attempt to auto discover the API server and connect
# to it. Uncomment only if the default does not work.
# - --apiserver-host=http://my-address:port

Answer 3

I had the same issue, struggled for days. This is what worked for me.

First, delete the secret corresponding to the kube-system namespace using the following command

kubectl delete secret secretName -n kube-system

The api-server will then create a new secret. Now delete the dashboard pod, and the new pod spun up by the rc/deployment will use the new secret and the errors corresponding to "credentials" should be gone.