GitHub Actions: Runners

Overview

GitHub Actions runners are the machines that run the jobs and steps in a GitHub Actions workflow. They are responsible for executing the commands defined in the workflow file and providing the necessary References for the tasks to be completed.

Runner types

There are two types of runners:

• Self-hosted runners: These are runners that you set up and manage on your own infrastructure. This allows you to have full control over the environment in which your jobs are executed, and you can use specialized hardware or software that may not be available on the GitHub-hosted runners.

• GitHub-hosted runners: These are runners that are provided and managed by GitHub. They are available on multiple operating systems, and they provide a variety of environments to run your jobs. These runners are free to use for public repositories, and for private repositories, you can use them for free for a certain number of minutes per month.

Examples

Here’s an example of how to specify the runner for a job in a workflow file:

jobs:
  build:
    runs-on: ubuntu-latest

In this example, the job is set to run on the latest version of Ubuntu, which is a GitHub-hosted runner.

You can also specify a self-hosted runner by using the name of the runner:

jobs:
  build:
    runs-on: self-hosted
    name: my-runner

In this example, the job is set to run on a self-hosted runner named “my-runner”.

To run the job on multiple runners, you can also specify a matrix of runners:

jobs:
  build:
    runs-on:
      - windows-latest
      - ubuntu-latest
      - macos-latest

In this example, the job is set to run on the latest versions of Windows, Ubuntu, and macOS.

It is important to note that the choice of runner will depend on the specific requirements of your workflow, such as the operating system, software dependencies, and hardware References needed.

Additionally, you can use the needs keyword to specify dependencies between jobs. For example, you can use it to specify that a job depends on another job being completed before it can start:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - name: Build
      run: make build

  test:
    needs: build
    runs-on: ubuntu-latest
    steps:
    - name: Test
      run: make test

In this example, the test job will not start until the build job is completed.

Summary

In summary, GitHub Actions runners are an essential component of a GitHub Actions workflow, providing the environment and References needed to execute the jobs and steps defined in the workflow file. Whether you choose to use self-hosted or GitHub-hosted runners, you should carefully consider the requirements of your workflow and choose the runner that best fits your needs.

Resources

• About GitHub-hosted runners
• About self-hosted runners