rules:
  - id: missing-dnf-clean-all
    severity: WARNING
    languages: [dockerfile]
    patterns:
      - pattern: RUN ... dnf ...
      - pattern-not-inside: RUN ... && dnf clean all
      - pattern-not-inside: RUN ... && \ dnf clean all
    message: >-
      This dnf command does not end with '&& dnf clean all'. Running 'dnf clean all' will remove cached data and reduce package size. (This must be performed in the same RUN step.)
    metadata:
      source-rule-url: https://github.com/hadolint/hadolint/wiki/DL3038
      references:
        - https://github.com/hadolint/hadolint/wiki/DL3038
      category: best-practice
      technology:
        - dockerfile