Move import of modulemd to a separate module

This should make it possible to only import the library only when it's
really needed.

DNF does not work with libmodulemd v2. If we import libmodulemd2 and
then dnf, the program will just hang forever. We only need DNF in
pungi-gather, where libmodulemd is not needed, and also where we do need
libmodulemd, we don't have DNF.

Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>

pungi/__init__.py

@@ -4,14 +4,6 @@ import os
 import re
 
 
-try:
-    import gi
-    gi.require_version('Modulemd', '2.0') # noqa
-    from gi.repository import Modulemd
-except (ImportError, ValueError):
-    Modulemd = None
-
-
 def get_full_version():
     """
     Find full version of Pungi: if running from git, this will return cleaned

pungi/module_util.py

@@ -0,0 +1,71 @@
+# -*- coding: utf-8 -*-
+
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Library General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, see <https://gnu.org/licenses/>.
+
+import glob
+import os
+
+try:
+    import gi
+
+    gi.require_version("Modulemd", "2.0")  # noqa
+    from gi.repository import Modulemd
+except (ImportError, ValueError):
+    Modulemd = None
+
+
+def iter_module_defaults(path):
+    """Given a path to a directory with yaml files, yield each module default
+    in there as a pair (module_name, ModuleDefaults instance).
+    """
+    # It is really tempting to merge all the module indexes into a single one
+    # and work with it. However that does not allow for detecting conflicting
+    # defaults. That should not happen in practice, but better safe than sorry.
+    # Once libmodulemd can report the error, this code can be simplifed by a
+    # lot. It was implemented in
+    # https://github.com/fedora-modularity/libmodulemd/commit/3087e4a5c38a331041fec9b6b8f1a372f9ffe64d
+    # and released in 2.6.0, but 2.8.0 added the need to merge overrides and
+    # that breaks this use case again.
+    for file in glob.glob(os.path.join(path, "*.yaml")):
+        index = Modulemd.ModuleIndex()
+        index.update_from_file(file, strict=False)
+        for module_name in index.get_module_names():
+            yield module_name, index.get_module(module_name).get_defaults()
+
+
+def collect_module_defaults(
+    defaults_dir, modules_to_load=None, mod_index=None, overrides_dir=None
+):
+    """Load module defaults into index.
+
+    If `modules_to_load` is passed in, it should be a set of module names. Only
+    defaults for these modules will be loaded.
+
+    If `mod_index` is passed in, it will be updated and returned. If it was
+    not, a new ModuleIndex will be created and returned
+    """
+    mod_index = mod_index or Modulemd.ModuleIndex()
+
+    temp_index = Modulemd.ModuleIndex.new()
+    temp_index.update_from_defaults_directory(
+        defaults_dir, overrides_path=overrides_dir, strict=False
+    )
+
+    for module_name in temp_index.get_module_names():
+        defaults = temp_index.get_module(module_name).get_defaults()
+
+        if not modules_to_load or module_name in modules_to_load:
+            mod_index.add_defaults(defaults)
+
+    return mod_index

pungi/phases/createrepo.py

@@ -33,13 +33,8 @@ from kobo.shortcuts import run, relative_path
 from ..wrappers.scm import get_dir_from_scm
 from ..wrappers.createrepo import CreaterepoWrapper
 from .base import PhaseBase
-from ..util import (
-    find_old_compose,
-    get_arch_variant_data,
-    collect_module_defaults,
-    temp_dir,
-)
-from pungi import Modulemd
+from ..util import find_old_compose, get_arch_variant_data, temp_dir
+from ..module_util import Modulemd, collect_module_defaults
 
 import productmd.rpms
 import productmd.modules

pungi/phases/gather/__init__.py

@@ -27,12 +27,12 @@ from .link import link_files
 from ...wrappers.createrepo import CreaterepoWrapper
 import pungi.wrappers.kojiwrapper
 
-from pungi import Modulemd
 from pungi.compose import get_ordered_variant_uids
 from pungi.arch import get_compatible_arches, split_name_arch
 from pungi.phases.base import PhaseBase
 from pungi.util import (get_arch_data, get_arch_variant_data, get_variant_data,
-                        makedirs, collect_module_defaults)
+                        makedirs)
+from pungi.module_util import Modulemd, collect_module_defaults
 from pungi.phases.createrepo import add_modular_metadata
 
 

pungi/phases/gather/methods/method_hybrid.py

@@ -23,13 +23,11 @@ import kobo.rpmlib
 from kobo.shortcuts import run
 
 import pungi.phases.gather.method
-from pungi import Modulemd, multilib_dnf
+from pungi import multilib_dnf
+from pungi.module_util import Modulemd
 from pungi.arch import get_valid_arches, tree_arch_to_yum_arch
 from pungi.phases.gather import _mk_pkg_map
-from pungi.util import (
-    get_arch_variant_data,
-    pkg_is_debug,
-)
+from pungi.util import get_arch_variant_data, pkg_is_debug
 from pungi.wrappers import fus
 from pungi.wrappers.comps import CompsWrapper
 

pungi/phases/init.py

@@ -23,7 +23,8 @@ from kobo.threads import run_in_threads
 
 from pungi.phases.base import PhaseBase
 from pungi.phases.gather import write_prepopulate_file
-from pungi.util import temp_dir, iter_module_defaults
+from pungi.util import temp_dir
+from pungi.module_util import iter_module_defaults
 from pungi.wrappers.comps import CompsWrapper
 from pungi.wrappers.createrepo import CreaterepoWrapper
 from pungi.wrappers.scm import get_dir_from_scm, get_file_from_scm

pungi/phases/pkgset/common.py

@@ -20,10 +20,10 @@ import threading
 from kobo.shortcuts import run, relative_path
 from kobo.threads import run_in_threads
 
-from pungi import Modulemd
 from pungi.arch import get_valid_arches
 from pungi.wrappers.createrepo import CreaterepoWrapper
-from pungi.util import is_arch_multilib, find_old_compose, collect_module_defaults
+from pungi.util import is_arch_multilib, find_old_compose
+from pungi.module_util import Modulemd, collect_module_defaults
 from pungi.phases.createrepo import add_modular_metadata
 
 

pungi/phases/pkgset/sources/source_koji.py

@@ -28,7 +28,7 @@ from pungi.wrappers.comps import CompsWrapper
 import pungi.phases.pkgset.pkgsets
 from pungi.arch import getBaseArch
 from pungi.util import retry, find_old_compose, get_arch_variant_data
-from pungi import Modulemd
+from pungi.module_util import Modulemd
 
 from pungi.phases.pkgset.common import MaterializedPackageSet, get_all_arches
 from pungi.phases.gather import get_packages_to_gather

pungi/util.py

@@ -15,7 +15,6 @@
 
 import argparse
 import fnmatch
-import glob
 import json
 import subprocess
 import os
@@ -36,8 +35,6 @@ import kobo.conf
 from kobo.shortcuts import run, force_list
 from productmd.common import get_major_version
 
-from pungi import Modulemd
-
 # Patterns that match all names of debuginfo packages
 DEBUG_PATTERNS = ["*-debuginfo", "*-debuginfo-*", "*-debugsource"]
 
@@ -926,52 +923,6 @@ def parse_koji_event(event):
         )
 
 
-def iter_module_defaults(path):
-    """Given a path to a directory with yaml files, yield each module default
-    in there as a pair (module_name, ModuleDefaults instance).
-    """
-    # It is really tempting to merge all the module indexes into a single one
-    # and work with it. However that does not allow for detecting conflicting
-    # defaults. That should not happen in practice, but better safe than sorry.
-    # Once libmodulemd can report the error, this code can be simplifed by a
-    # lot. It was implemented in
-    # https://github.com/fedora-modularity/libmodulemd/commit/3087e4a5c38a331041fec9b6b8f1a372f9ffe64d
-    # and released in 2.6.0, but 2.8.0 added the need to merge overrides and
-    # that breaks this use case again.
-    for file in glob.glob(os.path.join(path, "*.yaml")):
-        index = Modulemd.ModuleIndex()
-        index.update_from_file(file, strict=False)
-        for module_name in index.get_module_names():
-            yield module_name, index.get_module(module_name).get_defaults()
-
-
-def collect_module_defaults(
-    defaults_dir, modules_to_load=None, mod_index=None, overrides_dir=None
-):
-    """Load module defaults into index.
-
-    If `modules_to_load` is passed in, it should be a set of module names. Only
-    defaults for these modules will be loaded.
-
-    If `mod_index` is passed in, it will be updated and returned. If it was
-    not, a new ModuleIndex will be created and returned
-    """
-    mod_index = mod_index or Modulemd.ModuleIndex()
-
-    temp_index = Modulemd.ModuleIndex.new()
-    temp_index.update_from_defaults_directory(
-        defaults_dir, overrides_path=overrides_dir, strict=False
-    )
-
-    for module_name in temp_index.get_module_names():
-        defaults = temp_index.get_module(module_name).get_defaults()
-
-        if not modules_to_load or module_name in modules_to_load:
-            mod_index.add_defaults(defaults)
-
-    return mod_index
-
-
 def load_config(file_path, defaults={}):
     """Open and load configuration file form .conf or .json file."""
     conf = kobo.conf.PyConfigParser()

tests/helpers.py

@@ -18,7 +18,8 @@ except ImportError:
     import unittest
 
 from pungi.util import get_arch_variant_data
-from pungi import paths, checks, Modulemd
+from pungi import paths, checks
+from pungi.module_util import Modulemd
 
 
 class BaseTestCase(unittest.TestCase):

tests/test_createrepophase.py

@@ -19,7 +19,7 @@ from pungi.phases.createrepo import (CreaterepoPhase,
                                      get_productids_from_scm,
                                      ModulesMetadata)
 from tests.helpers import DummyCompose, PungiTestCase, copy_fixture, touch
-from pungi import Modulemd
+from pungi.module_util import Modulemd
 
 
 class TestCreaterepoPhase(PungiTestCase):

tests/test_gather_source_module.py

@@ -13,7 +13,7 @@ sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
 
 from pungi.phases.gather.sources.source_module import GatherSourceModule
 from tests import helpers
-from pungi import Modulemd
+from pungi.module_util import Modulemd
 
 
 @unittest.skipUnless(Modulemd is not None, "Skipped test, no module support.")

tests/test_initphase.py

@@ -13,7 +13,7 @@ import sys
 
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
 
-from pungi import Modulemd
+from pungi.module_util import Modulemd
 from pungi.phases import init
 from tests.helpers import DummyCompose, PungiTestCase, touch, mk_boom, fake_run_in_threads
 

tests/test_pkgset_common.py

@@ -8,7 +8,7 @@ import mock
 
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
 
-from pungi import Modulemd
+from pungi.module_util import Modulemd
 from pungi.phases.pkgset import common
 from tests import helpers
 

tests/test_pkgset_source_koji.py

@@ -14,7 +14,7 @@ sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
 
 from pungi.phases.pkgset.sources import source_koji
 from tests import helpers
-from pungi import Modulemd
+from pungi.module_util import Modulemd
 
 EVENT_INFO = {'id': 15681980, 'ts': 1460956382.81936}
 TAG_INFO = {
@@ -613,7 +613,7 @@ class MockModule(object):
         return self.path == other.path
 
 
-@mock.patch("pungi.Modulemd.ModuleStream.read_file", new=MockModule)
+@mock.patch("pungi.module_util.Modulemd.ModuleStream.read_file", new=MockModule)
 @unittest.skipIf(Modulemd is None, "Skipping tests, no module support")
 class TestAddModuleToVariant(helpers.PungiTestCase):