rules:
  - id: missing-image-version
    patterns:
      - pattern-either:
          - pattern: FROM $IMAGE
      - pattern-not: FROM $IMAGE:$VERSION
      - pattern-not: FROM $IMAGE@$DIGEST
      - pattern-not: FROM $IMAGE:$VERSION@$DIGEST
      - pattern-not: FROM scratch
    message: >-
      Detected docker image with no explicit version attached.
      Images should be tagged with an explicit version to produce
      deterministic container images -- attach a version when using 
      `FROM <image>`.
    severity: WARNING
    languages: [dockerfile]
    metadata:
      source-rule-url: https://github.com/hadolint/hadolint/wiki/DL3006
      references:
        - https://github.com/hadolint/hadolint/wiki/DL3006
      category: best-practice
      technology:
        - dockerfile