Known issues

The MKE 4k known issues with available workarounds are described herein.

Post-install kubelet parameter modifications require k0s restart

Modifications made to the kubelet parameters in the mke4.yaml configuration file after the initial MKE 4k installation require a restart of k0s on every cluster node. To do this:

1. Wait for a short time, roughly 60 seconds after the application of the mkectl apply command, to give the Pods time to enter their Running state.

2. Run the systemctl restart k0scontroller command on all manager nodes and the systemctl restart k0scontroller command on all worker nodes.

Upgrade may fail on clusters with two manager nodes

MKE 3 upgrades to MKE 4k may fail on clusters that have only two manager nodes.

Calico eBPF and IPVS modes are not supported

Calico eBPF and IPVS mode are not yet supported for MKE 4k. As such, upgrading from an MKE 3 cluster using either of those networking modes results in an error:

FATA[0640] Upgrade failed due to error: failed to run step [Upgrade Tasks]:
unable to install BOP: unable to apply MKE4 config: failed to wait for pods:
failed to wait for pods: failed to list pods: client rate limiter Wait returned
an error: context deadline exceeded

Managed user passwords are not migrated during upgrade from MKE 3

The admin password is migrated during upgrade from MKE 3, however all other managed user passwords are not migrated.

mke-operator in crashloopbackoff status

The mke-operator-controller-manager is in crashloopbackoff status in MKE 4k Alpha 2. You can safely ignore this, however, as it has no effect on MKE 4.0.0-alpha.2.0 functionality.

Upgrade to MKE 4k fails if kubeconfig file is present in source MKE 3.x

Upgrade to MKE 4k fails if the ~/.mke/mke.kubeconf file is present in the source MKE 3.x system.

Workaround:

Make a backup of the old ~/.mke/mke.kubeconf file and then delete it.

Once applied, the apiserver.externalAddress parameter cannot be cleared

MKE 4k cannot clear the apiserver.externalAddress parameter once it has been applied in the mke4.yaml configuration file, as this can cause the MKE cluster to malfunction.

No workaround is available at this time.

Upgrades from MKE 3 randomly fail while initializing k0rdent

Upgrades from MKE 3 to MKE 4k sometimes fail with the following error:

FTL Upgrade failed due to error: failed to run step [Install MKE 4 Components]: unable to initialize k0rdent after upgrading to mke4: failed to wait for KCM Manager to be ready: failed to wait for KCM Manager deployment to be ready: context deadline exceeded

Workaround:

Following a successful rollback, attempt the upgrade again, with no changes to the mkectl upgrade command.