Pre-commit Docker image

Pre-commit is a tool created by Yelp that allows you to run pre-commit sanity checks against your repo, to do things like ensuring private keys aren't being added etc. This image packages pre-commit in a docker-container, so you can ship it with a setup script you might be using to setup local development environment.

Usage

• Create .pre-commit-config.yaml in the root of your repo. For example

  - repo: git://github.com/pre-commit/pre-commit-hooks
    sha: master  # Use the ref you want to point at
    hooks:
      - { id: check-case-conflict }
      - { id: check-merge-conflict }
      - { id: check-symlinks }
      - { id: check-json }
      - { id: check-yaml }
      - { id: detect-private-key }
      - { id: end-of-file-fixer }
      - { id: trailing-whitespace }

• Add pre-commit script to .git/hooks/pre-commit

  cd $(git rev-parse --show-toplevel)
  
  NAME=$(basename `git rev-parse --show-toplevel`)_precommit
  docker ps -a | grep $NAME &> /dev/null
  CONTAINER_EXISTS=$?
  
  if [[ CONTAINER_EXISTS -eq 0 ]]; then
      docker restart $NAME && docker attach --no-stdin $NAME
  else
      docker run -t -v $(pwd):/pre-commit --name $NAME taghash/pre-commit
  fi
  

• Create an empty commit to test
  git commit --allow-empty -m "Test pre-commit"

Note

• If you are going to use a pre-commit plugin that needs dependencies not packaged in this image, you can extend this image and install the dependencies you need
• You might need to change the command, add volumes etc, based on your needs.
  For example, if you add { id: detect-aws-credentials } to .pre-commit-config.yaml, you have to mount the directory holding your aws credentials.
  The docker command (as in the pre-commit script) would then become

  docker run -t -v $(pwd):/pre-commit -v $HOME/.aws:/root/.aws:ro --name $NAME taghash/pre-commit