Goal is to investigate introducing linter for Dockerfile/Containerfile in our repository.
We don't have many of them, but if we keep moving toward containerizing tools/environments (e.g. CI test runner, Rebase tools dependencies, linters inside an image, future microshift e2e framework) then now seems to be best idea to set it up.

I heard about hadolint but if there's suitable alternative then we can also explore it.

$ find . -iname 'Containerfile*' -o -iname 'Dockerfile*'| grep -v "vendor\|_output"
./docs/config/Containerfile.tinyproxy
./packaging/images/openshift-ci/Dockerfile.test-runtime
./packaging/images/Containerfile.rpm-builder