6-protect-main.md

Lab 6: Protect the main Branch

In this lab, we're going to add a CODEOWNERS file, enable branch protections, and see what happens when we try to push any changes directly to main.

Scenario

Up until this point, we've been pushing changes directly to the default branch, main. When working with multiple developers in the same repo(s), this can cause many conflicts and other problems.

Task 1: Create a CODEOWNERS File

1. Ensure you're working on the main branch

   git checkout main

2. At the root of the repository, create a new file named CODEOWNERS with the following contents

   Replace your-username with your GitHub usernam. Make sure to leave the @ symbol!

   # Game Project Code Owners
   
   * @your-username
   

3. Add the CODEOWNERS file to the repository

   git add CODEOWNERS
   git commit -m "Add CODEOWNERS file"

4. Push the changes to GitHub

   git push

Task 2: Protect the main Branch

1. In your browser, navigate to your repository on GitHub

2. Click on the Settings tab

3. Expand Rules, then click Rulesets

4. Click New ruleset, then New branch ruleset

5. In the Ruleset name text field, enter a name for your rulset (e.g. Default Branch)

6. Set the Enforcement status to Active

   

7. In the Target branches section, click Add target, then click Include default branch!

   

8. In the Rules section, set the following:

   • Require a pull request before merging: Enabled
   • Required approvals: 1
   • Require review from Code Owners: Enabled

   

9. Click Create

Task 3: Try to Push Directly to main

Now that the main branch is protected, let's see what happens when we try to push changes directly to main.

1. In your terminal, make sure you're on the main branch

   git checkout main

2. Make a change any file in the repository

   For example, you could add a new line to the README.md file

   # GitHub Intermediate - Project Repository
   
   This is an update to the README.md file!

3. Add and commit the changes

   git add README.md
   git commit -m "Update README.md"

4. Push the changes to GitHub

   git push

   At this point, you should see an error message in your terminal, indicating that you cannot push changes directly to the main branch.

   remote: error: GH013: Repository rule violations found for refs/heads/main.
   remote: Review all repository rules at https://github.com/githubschool/gh-github-intermediate-template/rules?ref=refs%2Fheads%2Fmain
   remote:
   remote: - Changes must be made through a pull request.
   remote:
   To github.com:githubschool/gh-github-intermediate-template.git
    ! [remote rejected] main -> main (push declined due to repository rule violations)
   error: failed to push some refs to 'github.com:githubschool/gh-github-intermediate-template.git'
   

Task 4: Reset the main Branch

1. In your terminal, reset the main branch to the previous commit

   git reset --hard HEAD~1

Need Help?

If you're having trouble with any of the steps, you can ask for help in the meeting chat.