Understanding and Resolving GitHub Actions Permission Issues for Automated File Updates

If you’re venturing into automation with GitHub Actions, especially for tasks like scraping data and updating static files, encountering permission errors can be quite frustrating. Here’s a detailed look into a common issue many developers face: the notorious “permission denied” during automated commits.

Scenario Overview:
A developer has developed a custom scraper that fetches data from an external calendar and stores it in a JSON file. This JSON data is then displayed on an HTML site. To automate the updates, the developer has set up a GitHub Actions workflow that runs the scraper and attempts to commit the updated JSON file back to the repository.

The Problem:
While the scraping process executes successfully, the workflow fails at the commit stage, throwing a permission error similar to:

remote: Permission to (repository) denied to github-actions[bot].
fatal: unable to access '(repository URL)': The requested URL returned error: 403

This indicates that the GitHub Actions bot account does not have the necessary permissions to push changes to the repository, despite the presence of a token.

Possible Causes and Solutions:

1. Invalid or Insufficient Token Permissions
2. Ensure that the Personal Access Token (PAT) provided to GitHub Actions has the correct scopes. For repository write access, it should include repo scope.

3. Verify that the token is correctly stored as a secret in your repository and is used properly in the workflow.

4. Incorrect Token Usage in Workflow

5. Check that the workflow YAML file references the secret properly:
   “`yaml
   • name: Commit changes
     run: |
     git config –global user.name “github-actions[bot]”
     git config –global user.email “github-actions[bot]@users.noreply.github.com”
     git add .
     git commit -m “Automated update of JSON data”
     git push origin main
     env:
     GITHUB_TOKEN: ${{ secrets.YOUR_SECRET_NAME }}
     “`

6. If using a personal access token, ensure it’s used in place of the default GITHUB_TOKEN, which has limited permissions.

7. Using the Right Authentication Method

8. The default GITHUB_TOKEN provided by GitHub Actions has limited scope, and sometimes it cannot push to protected branches or certain repositories.
9. Generate a Personal Access Token with full write permissions, store it as a secret, and reference it during the push.

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