fix empty resource selectors which result to policy will not be consi…

[likakuli]

…dered matched

Signed-off-by: likakuli 1154584512@qq.com

What type of PR is this?

/kind bug

What this PR does / why we need it:
Override policy with empty resourceselectors should effective as nil which means match every resource.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

`karmada-controller-manager`: `OverridePolicy` with empty `ResourceSelector` will be considered to match all resources just like nil.

[RainbowMango]

/assign

[RainbowMango]

@huone1 Please help with it.

[likakuli]

Any problem with it?

[RainbowMango]

Sorry for let this sit. I'll try my best to look at it today.

[RainbowMango]

I guess we can't apply an empty ResourceSelector. E.g.

apiVersion: policy.karmada.io/v1alpha1
kind: PropagationPolicy
metadata:
  name: nginx-propagation
spec:
  resourceSelectors:
  placement:
    clusterAffinity:
      clusterNames:
        - member1
        - member2

Set ResourceSelector to empty, and this is not allowed:

error: error validating "samples/nginx/propagationpolicy.yaml": error validating data: ValidationError(PropagationPolicy.spec): missing required field "resourceSelectors" in io.karmada.policy.v1alpha1.PropagationPolicy.spec; if you choose to ignore these errors, turn validation off with --validate=false

I'm not saying this patch is not acceptable, just want to know your cases? Am I missing something?

[RainbowMango]

Sorry, ignore the common on above. What we are talking about is OverridePolicy.

Can you share your yamls here?

[RainbowMango]

apiVersion: policy.karmada.io/v1alpha1
kind: OverridePolicy
metadata:
  name: example-override
  namespace: default
spec:
  resourceSelectors:
  overrideRules:
    - targetCluster:
        clusterNames:
          - member1
      overriders:
        plaintext:
          - path: "/metadata/annotations"
            operator: add
            value:
              foo: bar

I get it. Your yaml might look like this resourceSelectors:.

[RainbowMango]

/lgtm
/approve

[karmada-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: RainbowMango

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 [RainbowMango]

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