Welcome to the Linux Foundation Forum!

Exercise 3.3: Finish Cluster Setup - Problem with coreDNS

Hello folks,

I am following Ex 3.3 step 6 to determine if the DNS and Calico pods are ready for use, and I am getting an error as below. Any ideas are welcome please!

~$ kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system calico-node-bdqnk 1/2 CrashLoopBackOff 1905 6d18h
kube-system calico-node-q7xxq 1/2 CrashLoopBackOff 753 2d16h
kube-system calico-node-z9hzj 1/2 Error 1904 6d18h
kube-system coredns-86c58d9df4-677v8 0/1 ContainerCreating 0 13m
kube-system coredns-86c58d9df4-t7b2h 0/1 ContainerCreating 0 13m
kube-system etcd-cicd 1/1 Running 0 6d18h
kube-system kube-apiserver-cicd 1/1 Running 0 6d18h
kube-system kube-controller-manager-cicd 1/1 Running 0 6d18h
kube-system kube-proxy-6bq6x 1/1 Running 0 2d16h
kube-system kube-proxy-jvk7w 1/1 Running 0 6d18h
kube-system kube-proxy-rkvms 1/1 Running 0 6d18h
kube-system kube-scheduler-cicd 1/1 Running 0 6d18h

Welcome!

It looks like you're new here. Sign in or register to get started.
Sign In

Comments

  • Posts: 1,000

    Hello,

    There are a few reasons the pods are not fully running. It depends on how far along in the labs you may be as there are some other steps to run in order that you have two nodes and both are willing to run all pods.

    When you ran kubeadm init --kubernetes-version 1.12.1 --pod-network-cidr 192.168.0.0/16 did you have any errors?
    Did you find any errors when you did the kubeadm join from the worker node?
    Were you able to remove the taints on both nodes?

    Regards,

  • Hi, some of these errors are expected in step 6, then step 7 helps with fixing them.
    Are your nodes local VMs or cloud VM instances?
    -Chris

  • I have a similar problem. coreDNS is not starting up.
    I am running the two nodes on bare metal. I am still in LAB 2.1 but everything installed and set up without error.

    1. kubectl get pods --all-namespaces
    2. NAMESPACE NAME READY STATUS RESTARTS AGE
    3. default firstpod-7d88d7b6cf-bj8js 1/1 Running 0 10m
    4. kube-system calico-etcd-wr2cf 1/1 Running 3 13h
    5. kube-system calico-kube-controllers-57c8947c94-g2lbc 1/1 Running 3 13h
    6. kube-system calico-node-lsjm9 2/2 Running 17 13h
    7. kube-system calico-node-zhgnd 2/2 Running 9 13h
    8. kube-system coredns-576cbf47c7-56thg 0/1 CrashLoopBackOff 53 13h
    9. kube-system coredns-576cbf47c7-nmznf 0/1 CrashLoopBackOff 53 13h
    10. kube-system etcd-nuc1 1/1 Running 4 13h
    11. kube-system kube-apiserver-nuc1 1/1 Running 4 13h
    12. kube-system kube-controller-manager-nuc1 1/1 Running 3 13h
    13. kube-system kube-proxy-ct89j 1/1 Running 3 13h
    14. kube-system kube-proxy-lbdxr 1/1 Running 5 13h
    15. kube-system kube-scheduler-nuc1 1/1 Running 3 13h

    When I describe the coreDNS pod I have the followin in the logs:

    1. Warning FailedMount 83m kubelet, nuc1 MountVolume.SetUp failed for volume "coredns-token-zwdp6" : couldn't propagate object cache: timed out waiting for the condition
    2. Normal SandboxChanged 83m (x2 over 83m) kubelet, nuc1 Pod sandbox changed, it will be killed and re-created.
    3. Normal Pulled 81m (x4 over 83m) kubelet, nuc1 Container image "k8s.gcr.io/coredns:1.2.2" already present on machine
    4. Normal Created 81m (x4 over 83m) kubelet, nuc1 Created container
    5. Normal Started 81m (x4 over 83m) kubelet, nuc1 Started container
    6. Warning BackOff 48m (x166 over 83m) kubelet, nuc1 Back-off restarting failed container
    7. Normal SandboxChanged 40m (x2 over 41m) kubelet, nuc1 Pod sandbox changed, it will be killed and re-created.
    8. Normal Pulled 39m (x4 over 40m) kubelet, nuc1 Container image "k8s.gcr.io/coredns:1.2.2" already present on machine
    9. Normal Created 39m (x4 over 40m) kubelet, nuc1 Created container
    10. Normal Started 39m (x4 over 40m) kubelet, nuc1 Started container
    11. Warning BackOff 59s (x194 over 40m) kubelet, nuc1 Back-off restarting failed container
  • @bryonbaker ,
    You can try to delete the 2 coredns pods, and they will be re-created.
    Are you in Lab 2.1 of LFD259?
    Thanks,
    -Chris

Welcome!

It looks like you're new here. Sign in or register to get started.
Sign In

Welcome!

It looks like you're new here. Sign in or register to get started.
Sign In

Categories

Upcoming Training