# Taskcluster Configuration

Taskcluster requires configuration of many resources to correctly support Firefox CI.
Many of those span multiple projects (branches) instead of riding the trains.

## Global Settings

The data behind configuration of all of these resources is kept in the [fxci-config] repository.
The files in this repository are intended to be self-documenting, but one of particular interest is `projects.yml`, which describes the needs of each project.

## Configuration Implementation

Translation of [fxci-config] to Taskcluster resources, and updating those resources, is handled by [ci-admin].
This is a small Python application with commands to generate the expected configuration, compare the expected to actual configuration, and apply the expected configuration.
Only the `apply` subcommand requires elevated privileges.

This tool automatically annotates all managed resources with "DO NOT EDIT", warning users of the administrative UI that changes made through the UI may be reverted.

## Changing Configuration

To change Taskcluster configuration, make patches to [fxci-config], using the Firefox Build System :: Task Configuration Bugzilla component.
The resulting configuration is applied upon landing.

See also the [releng documentation].

[ci-admin]: https://github.com/mozilla-releng/fxci-config/tree/main/src/ciadmin
[fxci-config]: https://github.com/mozilla-releng/fxci-config
[releng documentation]: https://docs.mozilla-releng.net/en/latest/how-to/taskcluster/ci_admin.html