Making CapacityBuffer ProvisioningStrategy a string (not enum)

[jakubin]

What type of PR is this?

/kind bug
/kind api-change

What this PR does / why we need it:

Different providers can have their own custom provisioning strategies. This field cannot be constrained by known in advance enum values.

Special notes for your reviewer:

Does this PR introduce a user-facing change?

CapacityBuffer ProvisioningStrategy is now a free string (not enum)

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

NONE

Make CapacityBuffer ProvisioningStrategy a string

[k8s-ci-robot]

Hi @jakubin. Thanks for your PR.

I'm waiting for a github.com member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[aleksandra-malinowska]

Can you briefly describe how this was tested?

Does this PR introduce a user-facing change?
NONE (only less validation on the field)

I'd say this is a user visible change - custom provisioning strategies are now allowed.

Otherwise LGTM

[aleksandra-malinowska]

/ok-to-test

[k8s-triage-robot]

This PR may require API review.

If so, when the changes are ready, complete the pre-review checklist and request an API review.

Status of requested reviews is tracked in the API Review project.

[jackfrancis]

/release-note-edit

Make CapacityBuffer ProvisioningStrategy a string

[jakubin]

Can you briefly describe how this was tested?

It was tested on GKE Cluster Autoscaler. CA reacted properly to a capacity buffer with an unsupported provisioning strategy - ignored it and didn't process.

[x13n]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: jakubin, x13n

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• cluster-autoscaler/OWNERS [x13n]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment