This directory contains chrome-infra's configs for its own services. Most of them are generated by lucicfg tool based on Starlark code. See main.star for configs of production services and dev.star for configs of development (aka staging) services.
After modifying any of the files, run ./main.star (or ./dev.star) to regenerate the configs. Presubmit checks will also remind you to do so.
Currently active version can be checked at https://luci-config.appspot.com/#/projects/infra .