policies/opa/classic/configmaps/8-deployment-latest-image-version.yaml

kind: ConfigMap
apiVersion: v1
metadata:
  name: deployment-valid-image-version
  namespace: opa
  labels:
    app: opa
    owner: jimmy
    openpolicyagent.org/policy: rego
data:
  main: |
    package kubernetes.admission

    import data.lib.k8s.helpers as helpers   

    deny[msg] {
      helpers.request_kind = "Deployment"
      helpers.allowed_operations[helpers.request_operation]
      image = helpers.deployment_containers[_].image
      invalid_image_version(image)
      msg = sprintf("%q: %q container image \"latest\" tag/version is not allowed. Resource ID (ns/name/kind): %q", [helpers.deployment_error,image,helpers.request_id])
    }

    invalid_image_version(image) {
      not contains(image, ":")
    }

    invalid_image_version(image) {
      contains(image, "latest")
    }