Image Without Digest

apiVersion: rules.spotter.dev/v1alpha1
kind: SpotterRule
metadata:
  name: spotter-supply-002
  labels:
    severity: "high"
    category: "supply"
  annotations:
    rules.spotter.dev/title: "Image Without Digest"
    rules.spotter.dev/version: "1.0.0"
    rules.spotter.dev/cwe: "CWE-829"
    rules.spotter.dev/description: "Container images should be referenced by digest rather than by tag to ensure immutability and prevent unexpected image changes."
spec:
  match:
    resources:
      kubernetes:
        apiGroups:
          - ""
          - "apps"
          - "batch"
        versions:
          - "v1"
        kinds:
          - Pod
          - Deployment
          - StatefulSet
          - DaemonSet
          - Job
          - CronJob
        namespaces:
          include: ["*"]
          exclude: ["kube-system", "kube-public"]
        labels:
          exclude:
            rules.spotter.dev/ignore: ["true"]
  cel: |
    (object.kind == 'Pod' && has(object.spec.containers) && object.spec.containers.exists(c, has(c.image) && !c.image.contains("@sha256:"))) ||
    (object.kind != 'Pod' && has(object.spec.template.spec.containers) && object.spec.template.spec.containers.exists(c, has(c.image) && !c.image.contains("@sha256:")))
  remediation:
    manual: "Update image references to use a digest (e.g., `myimage@sha256:digestvalue`) instead of a tag."
  references:
    - title: "Kubernetes Best Practices: Images"
      url: "https://kubernetes.io/docs/concepts/containers/images/"