kyverno/test/cli/test-validating-policy/json-check-dockerfile/policy.yaml

apiVersion: policies.kyverno.io/v1alpha1
kind: ValidatingPolicy
metadata:
  name: check-dockerfile-disallow-curl
spec:
  evaluation:
    mode: JSON
  validations:
    - message: "curl is not allowed"
      expression: >- 
        !object.Stages.exists(s, 
          s.Commands.exists(c, 
            has(c.CmdLine) && c.CmdLine.exists(cmd, string(cmd).contains('curl'))
          )
        )
---
apiVersion: policies.kyverno.io/v1alpha1
kind: ValidatingPolicy
metadata:
  name: check-dockerfile-disallow-wget
spec:
  evaluation:
    mode: JSON
  validations:
    - message: "wget is not allowed"
      expression: >- 
        !object.Stages.exists(s, 
          s.Commands.exists(c, 
            has(c.CmdLine) && c.CmdLine.exists(cmd, string(cmd).contains('wget'))
          )
        )
    - message: "HTTP calls are not allowed"
      expression: >- 
        !object.Stages.exists(s, 
          s.Commands.exists(c, 
            c.Args.exists(a, 
              a.Value.contains('http://') || a.Value.contains('https://')
            )
          )
        )