Configuring a GitHub Actions Runner on a Mac mini for enhanced CI/CD

GitHub Actions is a powerful CI/CD platform that allows users to automate their software development workflows, connected to a GitHub organization or repository. While GitHub offers online runners with a pay-as-you-go model, self-hosted runners provide increased control and customization for your CI/CD setup. This tutorial guides you through setting up, configuring, and connecting a self-hosted runner on a Mac mini to execute macOS pipelines.

Before you start

To complete the actions presented below, you must have:

• A Scaleway account logged into the console
• Owner status or IAM permissions allowing you to perform actions in the intended Organization
• A Mac mini
• A GitHub repository with administrator rights
• Installed a package manager, preferably Homebrew

Preparing for installation

Before starting the installation process, create a dedicated user account named gh-runner on your Mac mini and add it to the admin group. Execute the following terminal commands:

# Create the 'gh-runner' user account
sudo dscl . -create /Users/gh-runner
sudo dscl . -create /Users/gh-runner UserShell /bin/bash
sudo dscl . -create /Users/gh-runner RealName "GitHub runner"
sudo dscl . -create /Users/gh-runner UniqueID "1001"
sudo dscl . -create /Users/gh-runner PrimaryGroupID 20
sudo dscl . -create /Users/gh-runner NFSHomeDirectory /Users/gh-runner
# Set the password of the user. Replace 'password' with the actual password you want to configure for the user.
sudo dscl . -passwd /Users/gh-runner password
# Add 'gh-runner' to the 'admin' group
sudo dscl . -append /Groups/admin GroupMembership gh-runner

Use su to switch to the newly created gh-runner account for configuring the self-hosted runner.

su gh-runner

Installing Git and Rosetta 2

Ensure Git and Rosetta 2 are installed on your Mac mini:

git --version
# Assuming you have Homebrew installed. If not, follow the guides on https://brew.sh/ to install it.
brew install git

# Install Rosetta 2 if not already installed
softwareupdate --install-rosetta

Installing and configuring the runner

1. Navigate to your GitHub repository and go to Settings.

2. Click Actions under Code and automation, then select Runners. A list of your configured runners displays.

3. Click New self-hosted runner to be redirected to the configuration page.

4. Choose macOS as the runner image and ARM64 as the architecture.

5. Follow the prompted shell commands to authenticate your machine, download the necessary runtime, and set up the runner. Do not start your runner yet.

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   Note

   After selecting the runner image and architecture, GitHub prompts you to execute a sequence of shell commands. These commands serve to authenticate your machine with your GitHub repository, download the necessary runtime, and set up the runner within your environment. Execute these commands on your Mac mini.

6. Create a .env file in the runner _work folder for essential environment variables:

   # _work/.env file
   ImageOS=macos13
   XCODE_15_DEVELOPER_DIR=/Applications/Xcode.app/Contents/Developer

   Add any additional environment variables required by your actions.

   Tip

   If you have not yet installed Xcode on your machine, follow the official Apple Xcode documentation for further details.

7. Execute the run.sh script in your runner directory to complete the setup.

8. Verify that the runner is up and listening for jobs in the terminal and check the GitHub repository settings for the runner's association and Idle status.

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Using the runner in a workflow

The runner is authenticated to your repository and labeled with self-hosted, macOS, and ARM64. Use it in your workflows by specifying these labels in the runs-on field:

name: Sample workflow

on:
  workflow_dispatch:

jobs:
  build:
    runs-on: [self-hosted, macOS, ARM64]

    steps:
      - name: Install NodeJS
        run: brew install node

Sudoers configuration (optional)

If actions require root privileges, configure the sudoers file using sudo visudo. For private repositories, add:

gh-runner ALL=(ALL) NOPASSWD: ALL

runner ALL= NOPASSWD: /bin/hostname
# Or your additional applications with arguments:
runner ALL= NOPASSWD: /bin/hostname,/your_dir/your_bin your_args

Conclusion

This tutorial guided you through setting up a self-hosted runner on an Apple silicon-based Mac mini for macOS pipelines. Your runner is now ready to be integrated into your workflows. For additional information, refer to the managing self-hosted runners documentation on GitHub.