docker-check-shell

A Docker image with linters (such as ShellCheck⁠ and hadolint⁠) and formatters (such as shfmt⁠) for POSIX, Bash, and mksh shell code.

Table of Contents

• Getting the Image
• Usage
• Tools
  • ShellCheck
  • shfmt
  • Haskell Dockerfile Linter ("hadolint")
• Issues
• Contributing
• Authors
• License

Getting the Image

The image is hosted on Docker Hub and can be pulled down with:

$ docker pull fnichol/check-shell

Usage

This image is intended to be used primarily by CI systems or by developers who want these tools available on their workstation without explicitly installing them. As such, there is no entrypoint script and the default CMD is /bin/sh.

To use this image in a CI system such as Cirrus CI⁠, it is recommended that you use the :latest tag to track the latest published version. For example, in a .cirrus.yml file:

container:
  image: fnichol/check-shell:latest

check_task:
  check_script: find . -type f -name '*.sh' | xargs shellcheck

In a similar vein, you can use this image on your workstation with a locally running Docker Engine by mounting your current project directory into the container and running a tool such as shfmt⁠ like so:

$ docker run --rm -v "$(pwd):/src:ro" -w /src fnichol/check-shell \
    shfmt -i 2 -ci -bn -d -l build.sh

Tools

There are several shell linting tools installed into this image--the specific versions can be determined by inspecting the Dockerfile⁠.

ShellCheck

ShellCheck⁠ is a static analysis tool for shell scripts. The installed binary is taken from the official Docker image which is statically linked and the software is released under the GNU General Public License, v3⁠.

shfmt

shfmt⁠ is a subproject sh which is a shell parser, formatter, and interpreter. The shfmt tool focuses formatting POSIX Shell⁠, Bash⁠, and mksh⁠. The installed binary is taken from the official Docker image which is statically linked and the software is released under the BSD 3-Clause "New" or "Revised" License⁠

Haskell Dockerfile Linter ("hadolint")

The Haskell Dockerfile Linter⁠, usually known as "hadolint", is a Dockerfile linter that helps you build best practice⁠ Docker images. It has understanding of RUN instructions and lints their values as shell code. The installed binary is taken from the official Docker image which is statically linked and the software is released under the GNU General Public License, v3⁠

Issues

If you have any problems with or questions about this image, please contact us through a GitHub issue⁠.

Contributing

You are invited to contribute to new features, fixes, or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.

Before you start to code, we recommend discussing your plans through a GitHub issue⁠, especially for more ambitious contributions. This gives other contributors a chance to point you in the right direction, give you feedback on your design, and help you find out if someone else is working on the same thing.

Authors

Created and maintained by Fletcher Nichol⁠ (fnichol@nichol.ca⁠).

License

This Docker image is licensed under the MIT⁠ license.