Integrate clusterctl rollout into airshipctl

[lb4368]

Proposed change Integrate airshipctl with clusterctl rollout so that we can take advantage of the feature to rollout updates to the cluster currently being managed by airshipctl.

clusterctl rollout

• https://github.com/kubernetes-sigs/cluster-api/issues/3439
• clusterctl rollout command provides users with a convenient and consistent means through which to rollout an update, monitor the status of an update, rollback to a specific update and view the history of past updates.
• Currently focused on MachineDeployment with support for KubeadmControlPlane coming later.
• Long-term goal is to add the command under kubectl rollout.

Integrate with airshipctl cluster rollout

[lb4368]

@Arvinderpal - I believe you were going to take this one

[Arvinderpal]

Yes, please assign it to me.

[Arvinderpal]

Update: With v0.4.0, the rollout command is part of clusterctl. There are a couple of sub-commands, namely status and history that still need to be implemented. They are dependent https://github.com/kubernetes-sigs/cluster-api/issues/3486 which I'm also working on. Progress has been slow due to a lack of reviewers within the CAPI community.

Also, in airship, we have recently switched to using clusterctl as a binary (via KRM funcs). In the original model, clusterctl was consumed as a library and therefore to use these new commands, some level of code integration was needed. We may need to reassess how best to incorporate these commands.