[C, F] Using custom labels to route jobs
You can create custom labels and assign them to your self-hosted runners at any time. Custom labels let you send jobs to particular types of self-hosted runners, based on how they're labeled.
[E] Using default labels to route jobs
A self-hosted runner automatically receives certain labels when it is added to GitHub Actions.
These are used to indicate its operating system and hardware platform:
self-hosted: Default label applied to self-hosted runners.
linux, windows, or macOS: Applied depending on operating system.
x64, ARM, or ARM64: Applied depending on hardware architecture.
You can use your workflow's YAML to send jobs to a combination of these labels. In this example, a self-hosted runner that matches all three labels will be eligible to run the job:
runs-on: [self-hosted, linux, ARM64]
self-hosted - Run this job on a self-hosted runner.
linux - Only use a Linux-based runner.
ARM64 - Only use a runner based on ARM64 hardware.
Reference:
https://docs.github.com/en/actions/how-tos/manage-runners/self-hosted-runners/use-in-a- workflow