5 Runners
This chapter covers
- Getting to know GitHub runners
- What does the runner service do
- Using GitHub hosted runners
- Analyzing utilization of GitHub hosted runners
- When to use self-hosted runners
The runtime of GitHub Actions is provided by a service that is called Runners. Runners are standalone instances that continuously ask GitHub if there is work for them to execute. They provide the runtime for your job definitions: they will execute the steps defined in the job for you and provide information about the outcome back to GitHub, as well as the logs and any data uploaded to GitHub, for example artifacts and cache information.
In this chapter we will focus on the runners that GitHub hosts for you as a service. These are called GitHub hosted runners and come with certain compute power, preinstalled software, and are maintained with the latest security- and Operating System (OS) updates. Since GitHub does all the maintenance for you, there is a cost attached to using these runners. Depending on you plan, you will have a certain amount of action minutes included for free. See Paragraph 5.4, GitHub hosted runners, for more information.