kyverno/test/cli/test-validating-admission-policy/check-deployments-replica/policy.yaml

apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingAdmissionPolicy
metadata:
  name: "chech-deployment-replicas"
spec:
  matchConstraints:
    resourceRules:
    - apiGroups:   ["apps"]
      apiVersions: ["v1"]
      operations:  ["CREATE", "UPDATE"]
      resources:   ["deployments"]
  validations:
    - expression: "object.spec.replicas <= 2"
      message: "Deployment replicas must be less than or equal 2"