Add commit message blocker as GitHub Action

Author: platisd

Dockerfile

@@ -0,0 +1,14 @@
+FROM python:3.7-slim-buster
+
+RUN apt-get update
+RUN apt-get -y install git
+
+RUN pip3 install textblob
+RUN python3 -m textblob.download_corpora
+# nltk_data ends up in /root so python can't find it
+RUN ln -s /root/nltk_data /usr/local/nltk_data
+
+COPY entrypoint.sh /blocker/entrypoint.sh
+COPY bad_commit_message_blocker.py /blocker/bad_commit_message_blocker.py
+
+ENTRYPOINT ["/blocker/entrypoint.sh"]

README.md

@@ -6,7 +6,7 @@ A simple script, doing some natural language processing, to inhibit
 
 ## What?
 A Python3 script, easy to integrate with various CI machinery
-(e.g. see [TravisCI example](https://github.com/platisd/bad-commit-message-blocker/blob/master/.travis.yml))
+(e.g. see [GitHub Actions example](#github-action))
 that is meant to keep bad commit messages out of a project. It verifies
 whether the [seven rules of a great Git commit message](https://chris.beams.io/posts/git-commit/)
 by Chris Beams, are being followed:
@@ -66,4 +66,31 @@ appropriate arguments:
   * `--subject-limit` (defaults to `50`) to set the subject line limit. E.g.:
     * `python3 bad_commit_message_blocker.py --subject-limit 80 --message "Add a really cool feature"`
   * `--body-limit` (defaults to `72`) to set the body line limit. E.g.:
-    *  `python3 bad_commit_message_blocker.py --body-limit 120 --message "Add a really cool feature"`
+    *  `python3 bad_commit_message_blocker.py --body-limit 120 --message "Add a really cool feature"`
+
+## GitHub Action
+
+Now you can use this script as part of your **GitHub Actions** CI pipeline.
+
+An example configuration can be seen below:
+
+```yaml
+name: Commit messages
+
+on: [pull_request]
+
+jobs:
+  check-commit-message:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Verify commit messages follow best practices in CI
+        uses: platisd/bad-commit-message-blocker@master
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          # Optionally set the subject character limit (default `50`)
+          subject_limit: 60
+          # Optionally set the body character limit (default `72`)
+          body_limit: 100
+          # Optionally set the remote branch name to merge (default `master`)
+          remote_branch: dev
+```

action.yml

@@ -0,0 +1,24 @@
+name: 'Bad commit message blocker'
+description: 'Inhibit commits with bad messages from getting merged'
+inputs:
+  subject_limit:
+    description: 'The maximum allowed length for a commit subject'
+    required: true
+    default: 50
+  body_limit:
+    description: 'The maximum allowed length for a line in the commit body'
+    required: true
+    default: 72
+  remote_branch:
+    description: 'The name of the remote branch you are trying to merge with'
+    required: true
+    default: 'master'
+  github_token:
+    description: 'The GitHub token'
+    required: true
+runs:
+  using: 'docker'
+  image: 'Dockerfile'
+branding:
+  icon: 'check'  
+  color: 'green'

entrypoint.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+set -eu
+
+script_dir="$(dirname "$0")"
+cd $script_dir
+
+eval git clone "https://${INPUT_GITHUB_TOKEN}@github.com/${GITHUB_REPOSITORY}.git" ${GITHUB_REPOSITORY}
+cd $GITHUB_REPOSITORY
+eval git config remote.origin.fetch +refs/heads/*:refs/remotes/origin/*
+eval git fetch --all
+eval git checkout ${GITHUB_HEAD_REF:-$(basename ${GITHUB_REF})}
+
+commits_since_master=$(git rev-list HEAD ^origin/${INPUT_REMOTE_BRANCH})
+
+while read -r commit_hash; do
+    commit_message="$(git log --format=%B -n 1 ${commit_hash})"
+    python3 $script_dir/bad_commit_message_blocker.py \
+        --message "${commit_message}" \
+        --subject-limit "${INPUT_SUBJECT_LIMIT}" \
+        --body-limit "${INPUT_BODY_LIMIT}"
+done <<< "$commits_since_master"