Add a tool script for updating the certificates and private keys

[lfbear]

Signed-off-by: lfbear [email protected]

What type of PR is this?

1. converge function generate_cert_secret to util.sh
2. add a script for updating all certificates and private keys

What this PR does / why we need it:

For early users, the expiration date of certificates and private keys was only one year. The expiration of the cert will lead to an unavailable status for some components, such as Etcd.
This script will re-sign all certs and keys and update the related secrets in Karmada's host cluster. It will also update the credentials in Karmada's kubeconfig file.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

NONE

[karmada-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
To complete the pull request process, please ask for approval from lfbear after the PR has been reviewed.

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

Needs approval from an approver in each of these files:

• hack/OWNERS

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

[RainbowMango]

So glad that see you back @lfbear :)

[lonelyCZ]

Cool, I think this feature also need to be realized in karmadactl in the future.

[RainbowMango]

@chaosi-zju Please look at this.

I'm so sorry for missing this. Nowadays, a lot of users want a tools to update their certificates.

[chaosi-zju]

@chaosi-zju Please look at this.
I'm so sorry for missing this. Nowadays, a lot of users want a tools to update their certificates.

ok, I am interested in this PR too, review is on going.

But before I give any comments, I would like to spend some time investigating the official practice of k8s certificate rotation. since this is a key feature, we will strive to make it the best.

[RainbowMango]

Make sense.

[RainbowMango]

I hope this could be done along with karmada-io/community#69.