rules:
  - id: use-shell-instruction
    severity: WARNING
    languages: [dockerfile]
    pattern: |
      RUN ln ... $SHELL /bin/sh
    message: >-
      Use the SHELL instruction to set the default shell instead of overwriting '/bin/sh'.
    metadata:
      source-rule-url: https://github.com/hadolint/hadolint/wiki/DL4005
      references:
        - https://github.com/hadolint/hadolint/wiki/DL4005
      category: best-practice
      technology:
        - dockerfile
    fix: SHELL ["$SHELL", "-c"]