Github Action Merge Dependabot

This action automatically approves and merges dependabot PRs.

Usage

• install the GitHub App on the repositories or organization where you want to use this action. Using a GitHub App is necessary since this change GitHub introduced which limits the permissions of the provided GITHUB_TOKEN and the availability of secrets in Dependabot pull requests. The source code of the GitHub App is open source and hosted on Google Cloud Platform. You can also host your own version of the app and customize the api-url input to point to your hosted instance.
• configure this action in your workflows providing the inputs described below

Inputs

github-token

Required A GitHub token. See below for additional information.

exclude

Optional A comma separated value of packages that you don't want to auto-merge and would like to manually review to decide whether to upgrade or not.

approve-only

Optional If true, the PR is only approved but not merged. Defaults to false.

merge-method

Optional The merge method you would like to use (squash, merge, rebase). Default to squash merge.

merge-comment

Optional An arbitrary message that you'd like to comment on the PR after it gets auto-merged. This is only useful when you're recieving too much of noise in email and would like to filter mails for PRs that got automatically merged.

api-url

Optional A custom url where the external API which is delegated the task of approving and merging responds.

target

Optional A flag to only auto-merge updates based on Semantic Versioning. Defaults to any.

Possible options are:

major, premajor, minor, preminor, patch, prepatch, prerelease, any.

For more details on how semantic version difference is calculated please see semver package.

pr-number

Optional A pull request number, only required if triggered from a workflow_dispatch event. Typically this would be triggered by a script running in a seperate CI provider. See Trigger action from workflow_dispatch event

Example usage

Basic example

name: CI
on: [push, pull_request]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      # ...

  automerge:
    needs: build
    runs-on: ubuntu-latest
    steps:
      - uses: fastify/github-action-merge-dependabot@v2.1.1
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}

Excluding packages

steps:
  - uses: fastify/github-action-merge-dependabot@v2.1.1
    with:
      github-token: ${{ secrets.GITHUB_TOKEN }}
      exclude: 'react,fastify'

Approving without merging

steps:
  - uses: fastify/github-action-merge-dependabot@v2.1.1
    with:
      github-token: ${{ secrets.GITHUB_TOKEN }}
      approve-only: true

Trigger action from workflow_dispatch event

If you need to trigger this action manually, you can use the workflow_dispatch event. A use case might be that your CI runs on a seperate provider, so you would like to run this action as a result of a successful CI run.

When using the workflow_dispatch approach, you will need to send the PR number as part of the input for this action:

name: automerge

on:
  workflow_dispatch:
    inputs:
      pr-number:
        required: true

jobs:
  automerge:
    runs-on: ubuntu-latest
    steps:
      - uses: fastify/github-action-merge-dependabot@v2.2.0
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          pr-number: ${{ github.event.inputs.pr-number }}

You can initiate a call to trigger this event via API:

# Note: replace dynamic values with your relevant data
curl -X POST \
  -H "Accept: application/vnd.github.v3+json" \
  -H "Authorization: token {token}" \
  https://api.github.com/repos/{owner}/{reponame}/actions/workflows/{workflow}/dispatches \
  -d '{"ref":"{ref}", "inputs":{ "pr-number": "{number}"}}'

Notes

• A GitHub token is automatically provided by Github Actions, which can be accessed using secrets.GITHUB_TOKEN and supplied to the action as an input github-token.
• Only the GitHub native Dependabot integration is supported, the old Dependabot Preview app isn't.
• Make sure to use needs: <jobs> to delay the auto-merging until CI checks (test/build) are passed.
• If you want to use GitHub's auto-merge feature but still use this action to approve Pull Requests without merging, use approve-only: true.

Acknowledgements

This project is kindly sponsored by NearForm