README

This folder contains Git hooks for use in developing PerfKitBenchmarker, mostly adapted from kubernetes. Currently they ensure that all Python and shell scripts contain an Apache 2 license header, and that flake8 runs without generating lint errors. Install them by running:

hooks/install.sh

from the root of the repository. This will symlink the hooks into .git/hooks/.

The pre-push hook is currently opt-in. To enable it, set the PKB_BASE environment variable to the name of a base branch, for example PKB_BASE=upstream/dev for a fork, or PKB_BASE=origin/dev when working on the main repository.

You can also run checks manually:

# Run all checks on all files under version control.
hooks/check-everything

# Run all checks on a specific set of files.
hooks/check FILE ...

Implementation notes

The hook implementation is split into three layers:

• Toplevel hook scripts determine which files need to be checked, run the hooks/check script on them as needed, and report back errors. They use a nonzero return code when actions should be blocked (commit-msg or pre-push), and do other actions where needed. (prepare-commit-msg modifies the message.)

• The hooks/check script expects a list of files to check as arguments, and runs individual lib/check-* scripts on them. It prints optional human-readable diagnostics on STDERR, a formatted report on STDOUT (including offending filenames where available), and returns a nonzero exit code if any checks failed.

• lib/check-* scripts take a list of files to check as arguments. They can report file-specific issues by printing a list of bad files on STDOUT along with a zero exit code, or exit with a nonzero exit code if they find issues that can't be associated with a specific file such as a failed unit test or invalid testing setup.