Action — prek-home

Keeps prek's hook environments in a directory that outlives the job, such as a volume mounted into a self-hosted runner pod, instead of the GitHub cache. ci-prek runs it before j178/prek-action when its prek-home input is set; Hook environments on the node covers the volume to mount.

It runs two steps:

1. Select. Exports PREK_HOME=<path>/<key> for the next steps, where <key> is a hash of the prek release, RUNNER_OS, RUNNER_ARCH and every prek config (prek.toml, .prek.toml, .pre-commit-config.yaml, .pre-commit-config.yml) under working-directory, outside .git and node_modules. It touches <path>/<key>.lock under a shared flock: the file's modification time is the store's last use.
2. Clean. Deletes each store <path>/<16 hex digits>/ whose lock file is older than max-age-days, after taking an exclusive flock on it without waiting and checking the age again. A store that a run is choosing at that moment is kept. Other entries of <path> are never touched.

Usage

steps:
  - uses: KevinDeBenedetti/github-workflows/.github/actions/prek-home@main
    with:
      path: /var/cache/prek
      prek-version: 0.4.12
  - uses: j178/prek-action@4e14d07f9231acabce116ccfca13b13dd9755ece # v3.0.0
    with:
      prek-version: 0.4.12
      cache: false

Inputs

Input	Default	Description
path	(required)	Absolute path of the directory holding the stores; it must exist and be writable
working-directory	.	Directory holding the prek config
prek-version	(required)	prek release the job installs, part of the store key
max-age-days	14	Days a store may stay unused before it is deleted (1 to 9999)

Outputs

Output	Description
path	The store of this config, exported as PREK_HOME

Notes

• One store per config, on purpose. After a successful run, prek-action runs prek cache gc, which keeps only what the configs it can see need. In a store shared by several configs, a run would delete the environments of the others, possibly while another runner uses them.
• No lock around the install. prek locks the store itself (<store>/.lock) while it clones, installs and collects garbage, so runs of the same config can share their store.
• It fails with an ::error:: when path is not an absolute, existing, writable directory, or when flock is missing. It needs bash, flock (util-linux) and sha256sum (coreutils).
• The script is prek-home.sh; its tests are in tests/prek-home.bats.