Use namespace-aware meta importer for ipaplatform

Instead of symlinks and build-time configuration the ipaplatform module
is now able to auto-detect platforms on import time. The meta importer
uses the platform 'ID' from /etc/os-releases. It falls back to 'ID_LIKE'
on platforms like CentOS, which has ID=centos and ID_LIKE="rhel fedora".

The meta importer is able to handle namespace packages and the
ipaplatform package has been turned into a namespace package in order to
support external platform specifications.

https://fedorahosted.org/freeipa/ticket/6474

Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>

pypi/Makefile.am

@@ -7,7 +7,6 @@ NULL =
 SUBDIRS =			\
 	freeipa			\
 	ipa				\
-	ipaplatform		\
 	ipaserver		\
 	ipatests		\
 	$(NULL)

pypi/ipaplatform/Makefile.am

@@ -1,3 +0,0 @@
-include $(top_srcdir)/Makefile.python.am
-
-pkginstall = false

pypi/ipaplatform/README.txt

@@ -1,2 +0,0 @@
-This is a dummy package for FreeIPA's ipaplatform.
-

pypi/ipaplatform/ipaplatform/__init__.py

@@ -1,5 +0,0 @@
-#
-# Copyright (C) 2017 FreeIPA Contributors see COPYING for license
-#
-
-raise ImportError("ipaplatform is not yet supported as PyPI package.")

pypi/ipaplatform/setup.cfg

@@ -1,6 +0,0 @@
-[bdist_wheel]
-universal = 1
-
-[aliases]
-packages = clean --all egg_info bdist_wheel
-release = packages register upload

pypi/ipaplatform/setup.py

@@ -1,26 +0,0 @@
-#
-# Copyright (C) 2017 FreeIPA Contributors see COPYING for license
-#
-"""Dummy package for FreeIPA
-
-ipaplatform is not yet available as PyPI package.
-"""
-
-from os.path import abspath, dirname
-import sys
-
-if __name__ == '__main__':
-    # include ../../ for ipasetup.py
-    sys.path.append(dirname(dirname(dirname(abspath(__file__)))))
-    from ipasetup import ipasetup  # noqa: E402
-
-    ipasetup(
-        name='ipaplatform',
-        doc = __doc__,
-        packages=[
-            "ipaplatform",
-        ],
-        install_requires=[
-            "ipaclient",
-        ]
-    )

pypi/test_placeholder.py

@@ -9,13 +9,14 @@ import pytest
 
 @pytest.mark.parametrize("modname", [
     # placeholder packages raise ImportError
-    'ipaplatform',
     'ipaserver',
     'ipatests',
     # PyPI packages do not have install subpackage
     'ipaclient.install',
     'ipalib.install',
     'ipapython.install',
+    # override module should not be shipped in wheels
+    'ipaplatform.override',
 ])
 def test_fail_import(modname):
     try:
@@ -29,6 +30,7 @@ def test_fail_import(modname):
 @pytest.mark.parametrize("modname", [
     'ipaclient',
     'ipalib',
+    'ipaplatform',
     'ipapython',
 ])
 def test_import(modname):