Implement clusterctl KCP rollout command

[tobiasgiese]

User Story

As a user/operator I would like to be able to restart a KubeadmControlPlane rollout for any reason.

Detailed Description

It's possible that an Infra Machine needs to be recreated.
If a high-available (HA) KCP is provisioned, it's possible to delete each machine one after the other.
If a non-HA is provisioned, it's not that easy to re-create the Machine. There is the rolloutAfter field that can trigger a rolling update.

cluster-api/controlplane/kubeadm/api/v1beta1/kubeadm_control_plane_types.go

Lines 73 to 78 in 8fdaa34

	// RolloutAfter is a field to indicate a rollout should be performed
	// after the specified time even if no changes have been made to the
	// KubeadmControlPlane.
	//
	// +optional
	RolloutAfter *metav1.Time `json:"rolloutAfter,omitempty"`

For the machinedeployment there is already a clusterctl alpha rollout restart command implemented. We can easily adapt this for the kubeadmcontrolplane.

Anything else you would like to add:

Not sure if it's feasible to hard-code support for a control plane provider (KCP) into clusterctl, this feature would be very helpful -- at least for us 🙂

I already created a branch for the clusterctl KCP rollout command: https://github.com/mercedes-benz/cluster-api/tree/tobiasgiese/clusterctl-kcp-rollout

/kind feature
_{Tobias Giese tobias.giese@mercedes-benz.com, Mercedes-Benz Tech Innovation GmbH, legal info/Impressum}

[chrischdi]

maybe duplicate of #3439 ?

[jCOTINEAU]

Hello, i am also interested in this issue.

Right now we are updating the KubeadmControlPlane PreKubeadmCommands field, adding an envVar like

---
spec:
  kubeadmConfigSpec:
    preKubeadmCommands:
    - export RESTARDED_AT = some_date

As far as i know MachineDeployment can be rolled out by updating an annotation, but not KubeadmControlPlane, which require an update of the specs themselves.

I dont know if adding the same behavior could be a thing, so that we'll be able to add an easy rollout in clusterctl

[tobiasgiese]

maybe duplicate of #3439 ?

Thanks @chrischdi, will close this issue in favor of #3439

As far as i know MachineDeployment can be rolled out by updating an annotation, but not KubeadmControlPlane, which require an update of the specs themselves.

I already implemented the rollout for KCP, I'll create an PR in the next minutes 🙂

[tobiasgiese]

@jCOTINEAU PR is open

• ✨ Add KCP feature to clusterctl alpha rollout #6858