A Comprehensive Guide to Writing GitHub Actions by Use Case

Since I often run into issues when using GitHub Actions, I'm putting together this memo as a reference.

Setting environment variables

echo ::set-env name=NAME::name

To reuse a current environment variable across steps:

echo ::set-env name=NAME::$(echo NAME)

Running actions when pushing to the master branch

The pushed branch name is contained in github.ref.

- name update production
  if: github.ref == 'refs/heads/master' && github.event_name == 'push'
  run: ...

Running actions for PRs containing the string "release"

You can use contains to determine if a specific string is included in the branch name.
The following case is used when you want to merge a branch such as release/1.0.0 into master, etc.

- name release
  if: contains(github.head_ref, 'release') && github.event_name == 'pull_request'
  run: ...

Setting up AWS CLI

- name: Configure AWS credentials from bot account
  uses: aws-actions/configure-aws-credentials@v1
  with:
    aws-access-key-id: ${{ secrets.ACCESS_KEY }}
    aws-secret-access-key: ${{ secrets.SECRET_ACCESS_KEY }}
    aws-region: ap-northeast-1

Automatic tagging based on package.json

- name: package-version-to-git-tag
  uses: pkgdeps/action-package-version-to-git-tag@v1
  with:
    github_token: ${{ secrets.GITHUB_TOKEN }}
    github_repo: ${{ github.repository }}
    git_commit_sha: ${{ github.sha }}
    git_tag_prefix: ""