🐛 Backport clusterctl discovery fix to branch release-0.4

[Rozzii]

This patch was originally introduced in PR #5684.
Original name: "clusterctl discovery should ignore provider's resources"
Original commit id: db5b183

Original description:

While managing components (for cert-manager or providers) clusterctl
implements a discovery function to seek for all the objects
part of the component.

This commit makes this code to ignore resources for a provider
(e.g Cluster for CAPI, AWSCluster for CAPA, Certificates for cert-manager)
given that those resources are not part of the component itself.

This will make operations like upgrade plan or apply and delete resilient to actual
state of cert-manager web hooks; in fact, those operations can now work when
web-hooks are not functioning (due to provider's deployment already deleted,
to provider scaled down to 0, to other errors)

This commit also introduces some logic originally implemented in commit
f5a9d76 that implements the ability to skip excluded CRD during
resource listing.

Reason for backporting:

The issues that were solved by commit db5b183 and f5a9d76 on the main
branch are also effecting older releases of CAPI currently in use thus backporting
the "discovery fix" and some related code from f5a9d76 would solve a lot of issues
faced by users e.g related to upgrade process as mentioned in the original db5b183 commit.

[k8s-ci-robot]

Welcome @Rozzii!

It looks like this is your first PR to kubernetes-sigs/cluster-api 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes-sigs/cluster-api has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[k8s-ci-robot]

Hi @Rozzii. Thanks for your PR.

I'm waiting for a kubernetes-sigs 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.

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/test-infra repository.

[sbueringer]

/ok-to-test

[sbueringer]

@fabriziopandini To which branches should the fix be backported?
I saw you wanted to trigger a cherry-pick for release-1.0. This PR is for release-0.4.

[fabriziopandini]

yes, first the cherry-pick should go in release 1.0, and then in release 0.4

[sbueringer]

Thx, looks good as well!

/lgtm

[Rozzii]

/cc @fabriziopandini

[fabriziopandini]

/lgtm
/approve

I'm ok to backport to v1alpha4, given that this is the release where we reverted back to have webhooks and controllers in a single deployment, and this requires strict control on what kind of resources we access during an upgrade.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: fabriziopandini

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

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [fabriziopandini]

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