6 Self-hosted runners

In Chapter 5, Runners, we have seen how we can use GitHub hosted runners, for which purposes they can be used, as well as how billing works for those hosted runners. You can also install your own runners in your own environments. These are then called self-hosted runners. Creating self-hosted runners gives you full control over their execution environment, like placing it inside of the company network, or adding specific hardware or software capabilities. Self-hosted runners can also be beneficial from a cost perspective, since you do not need to pay any Action minutes to GitHub for jobs that run on self-hosted runners. There is, of course, a ‘cost’ associated with hosting, setup, and system administrative tasks that you will have to do to keep the environments you host the runners on up to date and secure.

6.1 Setting up self-hosted runners

6.1.1 Runner communication

6.1.2 Queued jobs

6.1.3 Updating self-hosted runners

6.1.4 Available runners

6.1.5 Downloading actions & source code

6.1.6 Runner capabilities

6.1.7 Self-hosted runner behind a proxy

6.1.8 Usage limits of self-hosted runners

6.1.9 Installing extra software

6.1.10 Runner service account

6.1.11 Pre- and post-job scripts

6.1.12 Adding extra information to your logs

6.1.13 Customizing the containers during a job

6.2 Security risks of self-hosted runners

6.3 Single use runners

6.3.1 Ephemeral runners

6.3.2 Just-in-time runners

6.4 Disabling self-hosted runner creation

6.5 Autoscaling options

6.5.1 Autoscaling with actions-runner-controller

6.5.2 Communication in ARC

6.5.3 ARC monitoring

6.6 Conclusion