This article provides basic troubleshooting steps for TKCs (Tanzu Kubernetes Cluster) stuck at creating phase.
Verify status of the TKC
- Use the following commands to verify the TKC status.
kubectl get tkc -n <supervisor_namespace>
kubectl get tkc -n <supervisor_namespace> -o json
kubectl describe tkc <tkc_name> -n <supervisor_namespace>
kubectl get cluster-api -n <supervisor_namespace>
kubectl get vm,machine,wcpmachine -n <supervisor_namespace>
Cluster health
- Verify health of the supervisor cluster.
❯ kubectl get node
NAME STATUS ROLES AGE VERSION
4201a7b2667b0f3b021efcf7c9d1726b Ready control-plane,master 86d v1.22.6+vmware.wcp.2
4201bead67e21a8813415642267cd54a Ready control-plane,master 86d v1.22.6+vmware.wcp.2
4201e0e8e29b0ddb4b59d3165dd40941 Ready control-plane,master 86d v1.22.6+vmware.wcp.2
wxx-08-r02esx13.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx14.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx15.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx16.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx17.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx18.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx19.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx20.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx21.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx22.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx23.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
wxx-08-r02esx24.xxxxxyyyy.com Ready agent 85d v1.22.6-sph-db56d46
❯
❯ kubectl get --raw '/healthz?verbose'
[+]ping ok
[+]log ok
[+]etcd ok
[+]poststarthook/start-kube-apiserver-admission-initializer ok
[+]poststarthook/generic-apiserver-start-informers ok
[+]poststarthook/priority-and-fairness-config-consumer ok
[+]poststarthook/priority-and-fairness-filter ok
[+]poststarthook/start-apiextensions-informers ok
[+]poststarthook/start-apiextensions-controllers ok
[+]poststarthook/crd-informer-synced ok
[+]poststarthook/bootstrap-controller ok
[+]poststarthook/rbac/bootstrap-roles ok
[+]poststarthook/scheduling/bootstrap-system-priority-classes ok
[+]poststarthook/priority-and-fairness-config-producer ok
[+]poststarthook/start-cluster-authentication-info-controller ok
[+]poststarthook/aggregator-reload-proxy-client-cert ok
[+]poststarthook/start-kube-aggregator-informers ok
[+]poststarthook/apiservice-registration-controller ok
[+]poststarthook/apiservice-status-available-controller ok
[+]poststarthook/kube-apiserver-autoregistration ok
[+]autoregister-completion ok
[+]poststarthook/apiservice-openapi-controller ok
healthz check passed
Terminating namespaces
- Check for namespaces stuck at terminating phase. If there are any, properly clean them up by removing all child objects.
- You can use this kubectl get-all plugin
to see all resources under a namespace. Then clean them up properly.
Mostly you need to set finalizers of remaining child resources to null.
Following is a sample case where 2 PVCs where stuck at terminating and
they were cleaned up by setting its finalizers to null.
❯ kg ns | grep Terminating
rgettam-gettam Terminating 226d
❯
❯ k get-all -n rgettam-gettam
NAME NAMESPACE AGE
persistentvolumeclaim/58ef0d27-ba66-4f4e-b4d7-43bd1c4fb833-c8c0c111-e480-4df4-baf8-d140d0237e1d rgettam-gettam 86d
persistentvolumeclaim/58ef0d27-ba66-4f4e-b4d7-43bd1c4fb833-e5c99b7e-1397-4a9d-b38c-53a25cab6c3f rgettam-gettam 86d
❯
❯ kg pvc -n rgettam-gettam
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
58ef0d27-ba66-4f4e-b4d7-43bd1c4fb833-c8c0c111-e480-4df4-baf8-d140d0237e1d Terminating pvc-bd4252fb-bfed-4ef3-ab5a-43718f9cbed5 8Gi RWO sxx-01-vcxx-wcp-mgmt 86d
58ef0d27-ba66-4f4e-b4d7-43bd1c4fb833-e5c99b7e-1397-4a9d-b38c-53a25cab6c3f Terminating pvc-8bc9daa1-21cf-4af2-973e-af28d66a7f5e 30Gi RWO sxx-01-vcxx-wcp-mgmt 86d
❯
❯ kg pvc -n rgettam-gettam --no-headers | awk '{print $1}' | xargs -I{} kubectl patch -n rgettam-gettam pvc {} -p '{"metadata":{"finalizers": null}}'
- You can also do kubectl get namespace <namespace> -oyaml and the status section will show if there are resources/ content to be deleted or any finalizers remaining.
- Verify vmop-controller pod logs, and restart them if required.
IP_BLOCK_EXHAUSTED
- Check CIDR usage of the supervisor cluster.
❯ kg clusternetworkinfos
NAME AGE
domain-c1006-06046c54-c9e5-41aa-bc2c-52d72c05bce4 160d
❯
❯ kg clusternetworkinfos domain-c1006-06046c54-c9e5-41aa-bc2c-52d72c05bce4 -o json | jq .usage
{
"egressCIDRUsage": {
"allocated": 33,
"total": 1024
},
"ingressCIDRUsage": {
"allocated": 42,
"total": 1024
},
"subnetCIDRUsage": {
"allocated": 832,
"total": 1024
}
} - When the IP blocks of supervisor cluster are exhausted, you will find the following warning when you describe the TKC.
Conditions:
Last Transition Time: 2022-10-05T18:34:35Z
Message: Cannot realize subnet
Reason: ClusterNetworkProvisionFailed
Severity: Warning
Status: False
Type: Ready - Also when you check the namespace, you can see the following ncp error IP_BLOCK_EXHAUSTED.
❯ kg ns tsql-integration-test -oyaml
apiVersion: v1
kind: Namespace
metadata:
annotations:
calaxxxx.xxxyy.com/xxxrole-created: "1"
ncp/error: IP_BLOCK_EXHAUSTED
ncp/router_id: t1_d0a2af0f-8430-4250-9fcf-807a4afe51aa_rtr
vmware-system-resource-pool: resgroup-307480
vmware-system-vm-folder: group-v307481
creationTimestamp: "2022-10-05T17:35:18Z"
Notes:
- If
the subnetCIDRUsage IP block is exhausted, you may need to remove some
old/ unused namespaces, and that will release some IPs. If that is not
possible, you may need to consider adding new subnet.
- After
removing the old/ unused namespaces, and even if IPs are available,
sometimes the TKCs will be stuck at creating phase! In that case, check
the ncp, vmop, and capw controller pods and you may need to restart
them. What I observed is usually after restart of ncp pod,
vmop-controller pods, and all pods under vmware-system-capw namespaces
the VMs will start getting deployed and the TKC creation will progress
and complete successfully.
Resource availability
- Check whether there are enough resources available in the cluster.
LAST SEEN TYPE REASON OBJECT MESSAGE
3m23s Warning UpdateFailure virtualmachine/magna3-control-plane-9rhl4 The host does not have sufficient CPU resources to satisfy the reservation.
80s Warning ReconcileFailure wcpmachine/magna3-control-plane-s5s9t-p2cxj vm is not yet powered on: vmware-system-capw-controller-manager/WCPMachine//chakravartha-magna3/magna3/magna3-control-plane-s5s9t-p2cxj
- Check for resource limits applied to the namespace.
Check whether storage policy is assigned to the namespace
27m Warning ReconcileFailure wcpmachine/gc-pool-0-cv8vz-5snbc admission webhook "default.validating.virtualmachine.vmoperator.xxxyy.com" denied the request: StorageClass wdc-10-vc21c01-wcp-pod is not assigned to any ResourceQuotas in namespace mpereiramaia-demo2
- In
this case, the storage policy wasnt assigned to the ns. I assigned the
storage policy wdc-10-vc21c01-wcp-pod to the respective namespace, and
the TKC deployment was successful.
Check Content library can sync properly
- Sometimes issues related to CL can cause TKCs to get stuck at creating phase! Check this blog post for more details.
KCP can't remediate
Message: KCP can't remediate if current replicas are less or equal then 1
Reason: WaitingForRemediation @ Machine/gc-control-plane-zpssc
Severity: Warning
- In
this case, you can just edit the TKC spec, change the control plane
vmclass to a different class and save. Once the deployment is complete
and TKC is running, edit the TKC spec again and revert the vmclass that
you modified earlier to its original class. This process will re-provision the control plane.
TKC VMs waiting for IP
- In this case, take a look at NSXT and check whether all Edge nodes are healthy. If there are mismatch errors, resolve them.
- You may also check ncp pod logs and restart ncp pod if required.
VirtualMachineClassBindingNotFound
Conditions:
Last Transition Time: 2021-05-05T18:19:10Z
Message: 1 of 2 completed
Reason: VirtualMachineClassBindingNotFound @ Machine/tkc-dev-control-plane-wxd57
Severity: Error
Status: False
Message: 0/1 Control Plane Node(s) healthy. 0/2 Worker Node(s) healthy
Events:
Normal PhaseChanged 7m22s vmware-system-tkg/vmware-system-tkg-controller-manager/tanzukubernetescluster-status-controller cluster changes from creating phase to failed phase
- This
happens when the virtualmachineclassbindings are missing and can be
resolved by adding all/ required VM Class to the Namespace using the
vSphere Client. Following are the steps to add VM Classes to a
namespace:
- Log into vCenter web UI
- From Hosts and Clusters > Select the namespace > Summary tab > VM Service tile > Click Manage VM Classes
- Select all required VM Classes and click OK
Verify NSX-T objects
- Issues at the NSX-T side can also cause the TKC to be stuck at creating phase. Following is a sample case and you can see these logs when you describe the TKC:
Message: 2 errors occurred:
* failed to configure DNS for /, Kind= namespace-test-01/gc: unable to reconcile kubeadm ConfigMap's CoreDNS info: unable to retrieve kubeadm Configmap from the guest cluster: configmaps "kubeadm-config" not found
* failed to configure kube-proxy for /, Kind= namespace-test-01/gc: unable to retrieve kube-proxy daemonset from the guest cluster: daemonsets.apps "kube-proxy" not found
In this case, these were some issues with the virtual servers in loadbalancer. Some stale entries of virtual servers were still present and their IP didn't get removed properly and it was causing some intermittent connectivity issues to some of the other services of type loadbalancer. And, new TKC deployment within that affected namespace also gets stuck due to this. In our case we deleted the affected namespace, and recreated it, that cleaned up all those virtual server state entries and the load balancer, and new TKC deployments were successful. So it will be worth to check on the health and staus of NSX-T objects in case you have TKC deployment issues.
Check for broken TKCs in the cluster
- Sometimes
the TKC deployments are very slow and takes more than 30 minutes. In
this case, you may notice that the first control plane VM will get
deployed in like 30-45 minutes after the TKC creation has started. Look
for vmop controller logs. Following is sample log:
❯ kail -n vmware-system-vmop
vmware-system-vmop/vmware-system-vmop-controller-manager-55459cb46b-2psrk[manager]: E1027 11:49:44.725620 1 readiness_worker.go:111] readiness-probe "msg"="readiness probe fails" "error"="dial tcp 172.29.9.212:6443: connect: connection refused" "vmName"="ciroscosta-cartographer/kontinue-control-plane-svlk4" "result"=-1
vmware-system-vmop/vmware-system-vmop-controller-manager-55459cb46b-2psrk[manager]: E1027 11:49:49.888653 1 readiness_worker.go:111] readiness-probe "msg"="readiness probe fails" "error"="dial tcp 172.29.2.66:6443: connect: connection refused" "vmName"="whaozhe-platform/gc-control-plane-mf4p5" "result"=-1
- In the above case, two of the TKCs were broken/ stuck at updating phase and we were unable to connect to its control plane.
ciroscosta-cartographer kontinue updating 2021-10-29T18:47:46Z v1.20.9+vmware.1-tkg.1.a4cee5b 1 2
whaozhe-platform gc updating 2022-01-27T03:59:31Z v1.20.12+vmware.1-tkg.1.b9a42f3 1 10
- After removing the namespaces with broken TKCs, new deployments were completing succesfully.
Restart system pods
- Sometimes
restart of some of the system controller pods resoves the issue. I
usually delete all the pods of the following namespaces and they will
get restarted in a few seconds.
k delete pod --all --namespace=vmware-system-vmop
k delete pod --all --namespace=vmware-system-capw
k delete pod --all --namespace=vmware-system-tkg
k delete pod --all --namespace=vmware-system-csi
k delete pod --all --namespace=vmware-system-nsx
Hope this was useful. Cheers!
