Troubleshoot cluster creation or upgrade

This page shows you how to investigate issues with cluster creation and upgrade in GKE on VMware.

If you need additional assistance, reach out to Cloud Customer Care.

Installation issues

The following sections might help you to troubleshoot issues with installing GKE on VMware.

Use the bootstrap cluster to debug issues

During installation, GKE on VMware creates a temporary bootstrap cluster. After a successful installation, GKE on VMware deletes the bootstrap cluster, leaving you with your admin cluster and user cluster. Generally, you should have no reason to interact with the bootstrap cluster. However, if you encounter issues during installation, you can use the bootstrap cluster logs to help you debug the problem.

If you pass --cleanup-external-cluster=false to gkectl create cluster, then the bootstrap cluster doesn't get deleted, and you can use the bootstrap cluster to debug installation issues.

Examine the bootstrap cluster's logs

  1. Find the names of Pods running in the kube-system namespace:

    kubectl --kubeconfig /home/ubuntu/.kube/kind-config-gkectl get pods -n kube-system

  2. View the logs for a Pod:

    kubectl --kubeconfig /home/ubuntu/.kube/kind-config-gkectl -n kube-system get logs POD_NAME

    Replace POD_NAME with the name of the Pod that you want to view.

  3. To get the logs from the bootstrap cluster directly, run the following command during cluster creation, update and upgrade:

    docker exec -it gkectl-control-plane bash

    This command opens a terminal inside the gkectl-control-plane container that runs in the bootstrap cluster.

  4. To inspect the kubelet and containerd logs, use the following commands and look for errors or warnings in the output:

    systemctl status -l kubelet
journalctl --utc -u kubelet
systemctl status -l containerd
journalctl --utc -u containerd

Examine the snapshot of the bootstrap cluster

If you attempt to create or upgrade an admin cluster, and that operation fails, GKE on VMware takes an external snapshot of the bootstrap cluster. This snapshot of the bootstrap cluster is similar to the snapshot taken by running the gkectl diagnose snapshot command on the admin cluster, but the process triggers automatically. The bootstrap cluster snapshot contains important debugging information for the admin cluster creation and upgrade process. You can provide this snapshot to Cloud Customer Care if needed.

The external snapshot includes Pod logs from the onprem-admin-cluster-controller that you can view to debug cluster creation or upgrade issues. The logs are stored in a separate file, for example:

kubectl_logs_onprem-admin-cluster-controller-6767f6597-nws8g_ \
    --container_onprem-admin-cluster-controller_ \
    --kubeconfig_.home.ubuntu..kube.kind-config-gkectl_\
    --namespace_kube-system

VM doesn't start after admin control plane starts

If a VM fails to start after the admin control plane has started, you can investigate the issue by inspecting the logs from the Cluster API controllers Pod in the admin cluster:

  1. Find the name of the Cluster API controllers Pod:

    kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG --namespace kube-system \
    get pods | grep clusterapi-controllers

  2. View logs from the vsphere-controller-manager. Start by specifying the Pod, but no container:

    kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG --namespace kube-system \
    logs POD_NAME

    The output tells you that you must specify a container, and it gives you the names of the containers in the Pod. For example:

    ... a container name must be specified ...,
choose one of: [clusterapi-controller-manager vsphere-controller-manager rbac-proxy]

  3. Choose a container, and view its logs:

    kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG --namespace kube-system \
    logs POD_NAME --container CONTAINER_NAME

Sufficient number of IP addresses allocated, but Machine fails to register with cluster

This issue can occur if there is an IP address conflict. For example, an IP address you specified for a machine is being used for a load balancer.

To resolve this issue, update your cluster IP block file so that the machine addresses do not conflict with addresses specified in your cluster configuration file or your Seesaw IP block file

Cluster upgrade issues

The following sections provide tips on how to resolve problems that you might encounter during a cluster upgrade.

Roll back a node pool after an upgrade

If you upgrade a user cluster and then discover an issue with the cluster nodes, you can roll back selected node pools to the previous version.

Rolling back selected node pools is supported for Ubuntu and COS node pools, but not for Windows node pools.

The version of a node pool can be the same or one minor version older than the version of the user cluster control plane. For example, if the control plane is at version 1.14, then the node pools can be at version 1.14 or 1.13.

View available node pool versions

Suppose you recently upgraded your user cluster worker nodes and control plane from version 1.13.1-gke.35 to version 1.14.0, and you discover an issue with the upgraded worker nodes. So you decide to roll back one or more node pools to the version you were previously running: 1.13.1-gke.35. Before you can begin the rollback, you need to verify that the previous version is available for rollback.

To view available versions, run the following command:

gkectl version --cluster-name USER_CLUSTER_NAME \
    --kubeconfig ADMIN_CLUSTER_KUBECONFIG

The output shows the current version and the previous version for each node pool. For example:

user cluster version: 1.14.0-gke.x

node pools:
- pool-1:
  - version: 1.14.0-gke.x
  - previous version: 1.13.1-gke.35
- pool-2:
  - version: 1.14.0-gke.x
  - previous version: 1.13.1-gke.35

available node pool versions:
- 1.13.1-gke.35
- 1.14.0-gke.x

Roll back node pool version

You can roll back a node pool's version one node pool at a time, or you can roll back several node pools in a single step.

To roll back a node pool version, complete the following steps:

  1. In your user cluster configuration file, in one or more node pools, set the value of gkeOnPremVersion to the previous version. The following example shows you how to roll back to version 1.13.1-gke.35:

    nodePools:
- name: pool-1
  cpus: 4
  memoryMB: 8192
  replicas: 3
  gkeOnPremVersion: 1.13.1-gke.35
  ...

  2. Update the cluster to roll back the node pool(s):

    gkectl update cluster --config USER_CLUSTER_CONFIG \
    --kubeconfig ADMIN_CLUSTER_KUBECONFIG

  3. Verify that the rollback was successful:

    gkectl version --cluster-name USER_CLUSTER_NAME \
    --kubeconfig ADMIN_CLUSTER_KUBECONFIG

    The following output shows that pool-1 was rolled back to version 1.13.1-gke.35.

    user cluster version: 1.14.0-gke.x

node pools:
- pool-1:
  - version: 1.13.1-gke.35
  - previous version: 1.14.0-gke.x
- pool-2:
  - version: 1.14.0-gke.x
  - previous version: 1.13.1-gke.35

available node pool versions:
- 1.13.1-gke.35
- 1.14.0-gke.x

Upgrade to a new patch version

You can upgrade all node pools and the control plane to a new patch version. This might be helpful if you rolled back to a previous version and want to upgrade to a version that includes a fix.

To upgrade to a new version, complete the following steps:

  1. Make the following changes in your user cluster configuration file:

    1. Set the value of gkeOnPremVersion to a new patch version. This example uses 1.14.1-gke.x.

    2. For each node pool, remove the gkeOnPremVersion field, or set it to the empty string. When no version is specified for a node pool, the version for the node pool defaults to the version specified for the cluster.

      These changes look similar to the following example:

      gkeOnPremVersion: 1.14.1-gke.x

nodePools:
-   name: pool-1
  cpus: 4
  memoryMB: 8192
  replicas: 3
  gkeOnPremVersion: ""
-   name: pool-2
  cpus: 8
  memoryMB: 8192
  replicas: 2
  gkeOnPremVersion: ""

  2. Run gkectl prepare and gkectl upgrade cluster as described in Upgrading GKE on VMware.

  3. Verify the new cluster version, and see the versions that are available for rollback:

    gkectl version --cluster-name USER_CLUSTER_NAME \
    --kubeconfig ADMIN_CLUSTER_KUBECONFIG

    The output is similar to the following:

     user cluster version: 1.14.1-gke.y

 node pools:
 - pool-1:
   - version: 1.14.1-gke.y
   - previous version: 1.13.1-gke.35
 - pool-2:
   - version: 1.14.1-gke.y
   - previous version: 1.13.1-gke.35

 available node pool versions:
 - 1.13.1-gke.35
 - 1.14.0-gke.x
 - 1.14.1-gke.y
 ```

Health checks are run automatically when cluster upgrade fails

If you attempt to upgrade an admin or user cluster, and that operation fails, GKE on VMware automatically runs the gkectl diagnose cluster command on the cluster.

To skip the automatic diagnosis, pass the --skip-diagnose-cluster flag to gkectl upgrade.

Upgrade process becomes stuck

Behind the scenes, GKE on VMware uses the Kubernetes drain command during an upgrade. This drain procedure can be blocked by a Deployment with only one replica that has a PodDisruptionBudget (PDB) created for it with minAvailable: 1.

From GKE on VMware version 1.13, you can check failures through Kubernetes Pod events.

  1. Find the names of the Machines:

    kubectl --kubeconfig USER_CLUSTER_KUBECONFIG get machines --all-namespaces

  2. Check for errors using the kubectl describe machine command:

    kubectl --kubeconfig USER_CLUSTER_KUBECONFIG describe machine MACHINE_NAME

    The output is similar to the following:

    Events:
  Type     Reason              Age    From                Message
  ----     ------              ----   ----                -------
  Warning  PodEvictionTooLong  3m49s  machine-controller  Waiting too long(12m10.284294321s) for pod(default/test-deployment-669b85c4cc-z8pz7) eviction.

  3. Optional: For a more detailed analysis on the machine objects status, run gkectl diagnose cluster.

    The output is similar to the following:

    ...
Checking machineset...SUCCESS
Checking machine objects...FAILURE
    Reason: 1 machine objects error(s).
    Unhealthy Resources:
    Pod test-deployment-669b85c4cc-7zjpq: Pod cannot be evicted successfully. There is 1 related PDB.
...
Checking all poddisruptionbudgets...FAILURE
    Reason: 1 pod disruption budget error(s).
    Unhealthy Resources:
    PodDisruptionBudget test-pdb: default/test-pdb might be configured incorrectly, the total replicas(3) should be larger than spec.MinAvailable(3).
...
Some validation results were FAILURE or UNKNOWN. Check report above.

To resolve this issue, save the PDB, and remove it from the cluster before attempting the upgrade. You can then add the PDB back after the upgrade is complete.

Remove unsupported changes to unblock upgrade

When upgrading clusters to 1.16 or earlier versions, changes to most fields are silently ignored during the upgrade, meaning that these changes don't take effect during and after the upgrade.

When upgrading user clusters to 1.28 or later versions, we validate all changes made in the configuration file and return an error for unsupported changes, instead of just ignoring them. This feature is for user clusters only. When upgrading admin clusters, changes to most fields are silently ignored and won't take effect after upgrade.

For example, if you attempt to disable node auto-repair when upgrading a user cluster to 1.28, the upgrade fails with the following error message:

failed to generate desired create config: failed to generate desired OnPremUserCluster from seed config: failed to apply validating webhook to OnPremUserCluster: the following changes on immutable fields are forbidden during upgrade: (diff: -before, +after):
   v1alpha1.OnPremUserClusterSpec{
    ... // 20 identical fields
    UsageMetering:         nil,
    CloudAuditLogging:     &{ProjectID: "syllogi-partner-testing", ClusterLocation: "us-central1", ServiceAccountKey: &{KubernetesSecret: &{Name: "user-cluster-creds", KeyName: "cloud-audit-logging-service-account-key"}}},
-   AutoRepair:            &v1alpha1.AutoRepairConfig{Enabled: true},
+   AutoRepair:            &v1alpha1.AutoRepairConfig{},
    CARotation:            &{Generated: &{CAVersion: 1}},
    KSASigningKeyRotation: &{Generated: &{KSASigningKeyVersion: 1}},
    ... // 8 identical fields
  }

If you need to bypass this error, there are the following workarounds:

  • Revert the attempted change, and then rerun the upgrade. For example, in the previous scenario, you would revert the changes made to the AutoRepair config and then rerun gkectl upgrade.
  • Alternatively, you can generate configuration files that match the current state of the cluster by running gkectl get-config, update the gkeOnPremVersion fields for the cluster and the node pools in the configuration file, and then rerun gkectl upgrade.

Debug F5 BIG-IP issues with the internal kubeconfig file

After an installation, GKE on VMware generates a kubeconfig file named internal-cluster-kubeconfig-debug in the home directory of your admin workstation. This kubeconfig file is identical to your admin cluster's kubeconfig file, except that it points directly to the admin cluster's control plane node, where the Kubernetes API server runs. You can use the internal-cluster-kubeconfig-debug file to debug F5 BIG-IP issues.

Debug issues with vSphere

You can use govc to investigate issues with vSphere. For example, you can confirm permissions and access for your vCenter user accounts, and you can collect vSphere logs.

Re-create missing user cluster kubeconfig file

You might want to re-create a user cluster kubeconfig file in the following situations:

  • If you attempt to create a user cluster, and the creation operation fails, and you want to have its user cluster kubeconfig file.
  • If the user cluster kubeconfig file is missing, such as after being deleted.

Run the following command to re-create the user cluster kubeconfig file:

kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG get secrets -n admin \
  -o jsonpath='{.data.admin\.conf}' | base64 -d  > USER_CLUSTER_KUBECONFIG

Replace the following:

  • USER_CLUSTER_KUBECONFIG: the name of the new kubeconfig file for your user cluster.
  • ADMIN_CLUSTER_KUBECONFIG: the path of the kubeconfig file for your admin cluster.

What's next