Feature: python: Add a python module wrapping libpacemaker.

This is a public, native python API that wraps libpacemaker.  It aims to
provide a python-based way of interacting with pacemaker, which means we
need to be careful to use exceptions where appropriate, return python
types, and in general write things in a pythonic style.

Author: clumens

mk/python.mk

@@ -9,7 +9,7 @@
 
 .PHONY: pylint
 pylint: $(PYCHECKFILES)
-	PYTHONPATH=$(abs_top_builddir)/python \
+	PYTHONPATH=$(abs_top_builddir)/python:$(abs_top_builddir)/python/pacemaker/.libs \
 	pylint --rcfile $(top_srcdir)/python/pylintrc $(PYCHECKFILES)
 
 # Disabled warnings:
@@ -27,5 +27,5 @@ pylint: $(PYCHECKFILES)
 # Disable docstrings warnings on unit tests.
 .PHONY: pyflake
 pyflake: $(PYCHECKFILES)
-	PYTHONPATH=$(abs_top_builddir)/python \
+	PYTHONPATH=$(abs_top_builddir)/python:$(abs_top_builddir)/python/pacemaker/.libs \
 	flake8 --ignore=W503,E402,E501,F401 --per-file-ignores="tests/*:D100,D101,D102,D104" $(PYCHECKFILES)

python/pacemaker/Makefile.am

@@ -18,7 +18,9 @@ _pcmksupport_la_LIBADD = $(top_builddir)/lib/pacemaker/libpacemaker.la
 
 pkgpython_PYTHON = __init__.py 		\
 		   _library.py 		\
-		   exitstatus.py
+		   exceptions.py 	\
+		   exitstatus.py 	\
+		   resource.py
 
 nodist_pkgpython_PYTHON = buildoptions.py
 

python/pacemaker/__init__.py

@@ -3,5 +3,7 @@
 __copyright__ = "Copyright 2023-2024 the Pacemaker project contributors"
 __license__ = "GNU Lesser General Public License version 2.1 or later (LGPLv2.1+)"
 
-from pacemaker.buildoptions import BuildOptions
-from pacemaker.exitstatus import ExitStatus
+from .buildoptions import BuildOptions
+from .exitstatus import ExitStatus
+from . import exceptions
+from . import resource

python/pacemaker/exceptions.py

@@ -0,0 +1,9 @@
+"""A module providing exceptions that can be raised by the Pacemaker module."""
+
+__all__ = ["PacemakerError"]
+__copyright__ = "Copyright 2025 the Pacemaker project contributors"
+__license__ = "GNU Lesser General Public License version 2.1 or later (LGPLv2.1+)"
+
+
+class PacemakerError(Exception):
+    """Base exception class for all Pacemaker errors."""

python/pacemaker/resource.py

@@ -0,0 +1,22 @@
+"""A module for managing cluster resources."""
+
+__all__ = ["list_standards"]
+__copyright__ = "Copyright 2025 the Pacemaker project contributors"
+__license__ = "GNU Lesser General Public License version 2.1 or later (LGPLv2.1+)"
+
+import libxml2
+
+import _pcmksupport
+from pacemaker.exceptions import PacemakerError
+
+
+def list_standards():
+    """Return a list of supported resource standards."""
+    try:
+        xml = _pcmksupport.list_standards()
+    except _pcmksupport.PacemakerError as e:
+        raise PacemakerError(*e.args) from None
+
+    doc = libxml2.xmlDoc(xml)
+
+    return [item.getContent() for item in doc.xpathEval("/pacemaker-result/standards/item")]

python/pylintrc

@@ -41,7 +41,7 @@ unsafe-load-any-extension=no
 # A comma-separated list of package or module names from where C extensions may
 # be loaded. Extensions are loading into the active Python interpreter and may
 # run arbitrary code
-extension-pkg-allow-list=
+extension-pkg-allow-list=_pcmksupport
 
 # Minimum supported python version
 # CHANGED