kyverno: [Bug] policy match Kind case-senstive

Kyverno Version

1.8.5

Description

I have an issue with a Kyverno ClusterPolicy skipping a resource it should match with. It seams like kyverno only supports kinds beginning with capital letters.

This issue happens both in a running cluster and using the CLI to test the policy.

It doesn’t matter if I only write the Kind or the fully qualified kind Group/Version/Kind It also doesn’t matter if the kind is upper or lower case in the ClusterPolicy match rule.

No matter what it only matches if the kind for the resource starts with a capital letter. I am not able to change the CRD since it is owned by the postgres-operator reepo and I also believe this is a general issue.

To recreate

1. Create the following three files in a folder

# policy.yaml
apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: test
spec:
  generateExistingOnPolicyUpdate: true
  rules:
    - name: test-rule
      match:
        any:
          - resources:
              kinds:
                -  "acid.zalan.do/v1/postgresdb"
      generate:
        synchronize: true
        apiVersion: networking.k8s.io/v1
        kind: NetworkPolicy
        name: dummy
        namespace: "{{request.object.metadata.namespace}}"

# postgres_lower.yaml
apiVersion: acid.zalan.do/v1
kind: postgresdb
metadata:
  name: acid-minimal-cluster
spec: {}

# postgres_upper.yaml
apiVersion: acid.zalan.do/v1
kind: Postgresdb
metadata:
  name: acid-minimal-cluster
spec: {}

1. Then running the kyverno cli to show the issue:

foo@bar test % kyverno apply policy.yaml --resource postgres_lower.yaml

Applying 1 policy rule to 1 resource...

pass: 0, fail: 0, warn: 0, error: 0, skip: 1

foo@bar test % kyverno apply policy.yaml --resource postgres_upper.yaml

Applying 1 policy rule to 1 resource...

pass: 1, fail: 0, warn: 0, error: 0, skip: 0 

As can be seen on the output, the kind: postgresdb is not matches but the kind: Postgresdb is even though the rule is acid.zalan.do/v1/postgresdb

Slack discussion

No response

Troubleshooting

• I have read and followed the documentation AND the troubleshooting guide.
• I have searched other issues in this repository and mine is not recorded.