There are |num_ci_runners| CI/CD runners and they are running as systemd jobs on |control_host|.
The workflows are located in the .github folder of the kayobe config. They can be run by going to the actions section of |kayobe_config_source_url|. Each workflow has it's own configuration opetions and depending on the workflow you choose you may be able to add limits to the command you are going to run.
For example, if you were to run the Run Overcloud Service Deploy workflow you are given the option to limit the hosts that this command runs on and to limit the services that are deployed. This is useful for making changes to the kayobe config and limiting them to a single node to ensure everything is working as expected.
Additonally, on every PR to the kayobe config repo, the Config Diff workflow is run. This workflow will run a diff between the current kayobe config and the proposed changes. This is useful for ensuring that the changes you are making are what you expect them to be.