These are various tools that can be use for linting of Dockerfiles.
Haskell Dockerfile Linter (hadolint).
A smarter Dockerfile linter that helps you build best practice Docker images. The linter parses the Dockerfile into an AST and performs rules on top of the AST. It stands on the shoulders of ShellCheck to lint the Bash code inside RUN instructions.
To run hadolint inside a Docker container to lint a Dockerfile:
docker run --rm -i hadolint/hadolint < Dockerfile