如何让Github Actions仅在特定分支向master发起PR时运行？

Let's break down what went wrong with your original configuration and fix it step by step.

The Problem with Your Current Setup #

Your existing branches field in the on: pull_request section specifies target branches—meaning the workflow triggers whenever a PR is opened to master or any skip-* branch. That's why it's running for all PRs to master, regardless of which branch the PR comes from.

Solution 1: Filter at the Job Level (Flexible) #

This approach first triggers the workflow for all PRs to master, then filters out any PRs that don't come from a skip-* branch before running the job:

name: Auto Approve Pull Request
on:
  pull_request:
    branches:
      - 'master'  # Only trigger for PRs targeting master
jobs:
  build:
    name: Approve PR
    runs-on: ubuntu-latest
    # Only run this job if the source branch starts with "skip-"
    if: startsWith(github.head_ref, 'skip-')
    steps:
      - name: Fetch our code
        uses: username/my-github-repo@master
        with:
          # Use a GitHub Secret instead of hardcoding your token!
          token: ${{ secrets.GITHUB_TOKEN }}
        env:
          BRANCH_PREFIX: "skip-"
          PULL_REQUEST_TARGET_BRANCH: "master"

Solution 2: Filter at the Event Level (More Efficient) #

If you want to avoid triggering the workflow entirely for non-matching PRs, use head_refs to specify allowed source branches alongside the target master branch:

name: Auto Approve Pull Request
on:
  pull_request:
    branches:
      - 'master'  # Target branch is master
    head_refs:
      - 'skip-*'  # Only allow source branches matching skip-*
jobs:
  build:
    name: Approve PR
    runs-on: ubuntu-latest
    steps:
      - name: Fetch our code
        uses: username/my-github-repo@master
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
        env:
          BRANCH_PREFIX: "skip-"
          PULL_REQUEST_TARGET_BRANCH: "master"

Key Notes: #

• Avoid hardcoding tokens: Always use GitHub Secrets (like ${{ secrets.GITHUB_TOKEN }} or a custom secret) to keep your credentials secure.
• github.head_ref: This variable holds the name of the source branch that the PR is coming from—perfect for filtering which PRs run your job.

内容的提问来源于stack exchange，提问作者Njeri Ngigi