kyverno/examples/validate/check_cpu_memory.yaml

apiVersion : kyverno.io/v1alpha1
kind: Policy
metadata:
  name: check-cpu-memory
spec:
  rules:
  - name: check-defined
    resource:
      kinds:
      - Deployment
    validate:
      message: "Resource limits are required for CPU and memory"
      pattern:
        spec:
          template:
            spec:
              containers:
              - name: "?*"
                resources:
                  limits:
                    memory: "?*"
                    cpu: "?*"

  - name: check-cpu
    resource:
      kinds:
      - Deployment
    validate:
      message: "CPU request should be less than 4"
      pattern:
        spec:
          template:
            spec:
              containers:
              - name: "*"
                resources:
                  requests:
                    cpu: "<4m"