Background

setup.py installs the config tree (clush.conf, groups.conf, the *.d/
dirs and *.example files) through setuptools data_files at the relative path
etc/clustershell/. In a wheel / PEP 517 install that path is placed relative
to the install location, so:

• venv → <venv>/etc/clustershell/ ✅ (found via config_paths()'s
  sys.prefix/etc/clustershell entry)
• pip install --user → ~/.local/etc/clustershell/ ✅
• system /usr prefix → /usr/etc/clustershell/ ❌ (not /etc)

The last one is the awkward case: Python packaging has no notion of a system
/etc, and data_files ties everything to the install location. Today we work
around it with (a) the multi-path search in Defaults.config_paths() and (b) the
RPM spec moving /usr/etc → %{_sysconfdir}. It works, but it surprises people.

(Man pages are not affected: share/man lands at /usr/share/man under a /usr
prefix, which is correct. This is specific to the etc/ config dir.)

Proposal (do this at the Python 2 drop)

Dropping py2 is the natural time — we move to a pyproject.toml build (started in
#606) and can stop using data_files for config. Let each install channel place
config itself instead of forcing it through the package:

• Distro packages own /etc: the spec installs conf/* to
  %{_sysconfdir}/clustershell directly (the same way it already installs man
  pages and vim files), so the data_files route and the /usr/etc → /etc
  move both go away.

• pip/venv ships the library only (it already runs on built-in defaults).
  Two options for the example configs:

  • (a) keep them in the sdist conf/ for packagers and docs, and don't install
    them into the environment at all; or
  • (b) carry them as package_data inside the package, readable via
    importlib.resources, so pip/venv users can still find reference copies.

  Leaning (b); (a) is simpler.

Note: the pyproject.toml in #606 doesn't yet install config files or man pages,
so handling those is part of finishing that migration — this issue covers config.

Behavior change / things to watch

• venv & pip users currently get example configs dropped at
  <prefix>/etc/clustershell; after this they won't. Document
  CLUSTERSHELL_CFGDIR and copying the examples in the migration notes.
• config_paths()'s sys.prefix/etc/clustershell entry would no longer be
  filled by an install — keep it for backward compatibility, or remove it on
  purpose.
• importlib.resources.files() needs Python 3.9+; if the minimum Python version
  is lower then, use the importlib_resources backport or the older API.

Acceptance criteria

• once on pyproject.toml (From setup.py to pyproject #606), config files are no longer installed via data_files
• example configs handled per chosen option (sdist-only or package_data)
• Fedora + EL spec(s) install /etc/clustershell directly; /usr/etc → /etc move removed
• venv install no longer creates <prefix>/etc/clustershell; library still runs on defaults
• docs note where config lives per install channel

Related

• From setup.py to pyproject #606 — setup.py → pyproject.toml migration (the migration this depends on)
• Fedora Packaging: Stop using deprecated python setup.py build/install command in the spec #587 — Fedora packaging: stop using deprecated setup.py build/install
• Request for a Pure Python Wheel #634 — pure-Python wheel request (where this surfaced)