Known issues

MKE 3.8.2 known issues with available workaround solutions include:

[MKE-10152] Upgrading large Windows clusters can initiate a rollback

Upgrades can rollback on a cluster with a large number of Windows worker nodes.

Workaround:

Invoke the --manual-worker-upgrade option and then manually upgrade the workers.

[MKE-9699] Ingress Controller with external load balancer can enter crashloop

Due to the upstream Kubernetes issue 73140, rapid toggling of the Ingress Controller with an external load balancer in use can cause the resource to become stuck in a crashloop.

Workaround:

  1. Log in to the MKE web UI as an administrator.

  2. In the left-side navigation panel, navigate to <user name> > Admin Settings > Ingress.

  3. Click the Kubernetes tab to display the HTTP Ingress Controller for Kubernetes pane.

  4. Toggle the HTTP Ingress Controller for Kubernetes enabled control to the left to disable the Ingress Controller.

  5. Use the CLI to delete the Ingress Controller resources:

    kubectl delete service ingress-nginx-controller-admission --namespace ingress-nginx
    kubectl delete deployment ingress-nginx-controller --namespace
    ingress-nginx
    
  6. Verify the successful deletion of the resources:

    kubectl get all --namespace ingress-nginx
    

    Example output:

    No resources found in ingress-nginx namespace.
    
  7. Return to the HTTP Ingress Controller for Kubernetes pane in the MKE web UI and change the nodeport numbers for HTTP Port, HTTPS Port and TCP Port.

  8. Toggle the HTTP Ingress Controller for Kubernetes enabled control to the right to re-enable the Ingress Controller.

[MKE-8914] Windows Server Core with Containers images incompatible with GCP

The use of Windows ServerCore with Containers images will prevent kubelet from starting up, as these images are not compatible with GCP.

As a workaround, use Windows Server or Windows Server Core images.

[MKE-8814] Mismatched MTU values cause Swarm overlay network issues on GCP

Communication between GCP VPCs and Docker networks that use Swarm overlay networks will fail if their MTU values are not manually aligned. By default, the MTU value for GCP VPCs is 1460, while the default MTU value for Docker networks is 1500.

Workaround:

Select from the following options:

  • Create a new VPC and set the MTU value to 1500.

  • Set the MTU value of the existing VPC to 1500.

For more information, refer to the Google Cloud Platform documentation, Change the MTU setting of a VPC network.

[MKE-12030] MKE telemetry setting overrides key/value in daemon.json

MKE removes the telemetry key/value from the MCR 25 daemon.json file configuration.

Workaround:

Disable the telemetry function.

  • Users running MKE 3.x in addition to MCR 25.x:

    1. Verify that you have a valid license affixed to MKE.

    2. Log in to the MKE web UI as an administrator.

    3. In the left-side navigation panel, navigate to <user name> > Admin > Config.

    4. Disable both options under Usage Reporting and click Save.

    5. Verify the presence of "telemetry": false in the ``/etc/docker/daemon.json``file.

    6. Run sudo systemctl reload docker.service on all manager nodes.

  • All other users must directly edit the daemon.json file to include "telemetry": false.

[FIELD-7469] storage_expt_enabled set to true prevents kubelet start up

Kubelet does not start when the storage_expt_enabled MKE configuration parameter is set to true.

Workaround:

Modify the MKE configuration file to set the torage_expt_enabled parameter to false.