Add singleton system_resolver

system_resolver is created based on loaded configuration, which could
avoid calls like `GenericResolver.create(conf)` repeatedly in the code.

However, if some cases need to create a specific resolver explicitly,
`GenericResolver.create` could be called with addition argument, for
example db or mbs is passed to argument backend in tests.

Signed-off-by: Chenxiong Qi <cqi@redhat.com>

tests/test_builder/test_base.py

@@ -24,6 +24,7 @@ import mock
 
 import module_build_service.models
 import module_build_service.builder
+import module_build_service.resolver
 
 from tests import init_data, db
 
@@ -48,31 +49,33 @@ class TestGenericBuilder:
         resolver = mock.MagicMock()
         resolver.backend = 'mbs'
         resolver.resolve_profiles.return_value = mbs_groups
-        generic_resolver.create.return_value = resolver
 
         expected_groups = {
             "build": [],
             "srpm-build": []
         }
 
-        # Call default_buildroot_groups, the result should be cached.
-        ret = GenericBuilder.default_buildroot_groups(db.session, self.module)
-        assert ret == expected_groups
-        resolver.resolve_profiles.assert_called_once()
-        resolver.resolve_profiles.reset_mock()
+        with patch.object(module_build_service.resolver, 'system_resolver', new=resolver):
+            # Call default_buildroot_groups, the result should be cached.
+            ret = GenericBuilder.default_buildroot_groups(db.session, self.module)
+            assert ret == expected_groups
+            resolver.resolve_profiles.assert_called_once()
+            resolver.resolve_profiles.reset_mock()
 
         # Now try calling it again to verify resolve_profiles is not called,
         # because it is cached.
-        ret = GenericBuilder.default_buildroot_groups(db.session, self.module)
-        assert ret == expected_groups
-        resolver.resolve_profiles.assert_not_called()
-        resolver.resolve_profiles.reset_mock()
+        with patch.object(module_build_service.resolver, 'system_resolver', new=resolver):
+            ret = GenericBuilder.default_buildroot_groups(db.session, self.module)
+            assert ret == expected_groups
+            resolver.resolve_profiles.assert_not_called()
+            resolver.resolve_profiles.reset_mock()
 
         # And now try clearing the cache and call it again.
-        GenericBuilder.clear_cache(self.module)
-        ret = GenericBuilder.default_buildroot_groups(db.session, self.module)
-        assert ret == expected_groups
-        resolver.resolve_profiles.assert_called_once()
+        with patch.object(module_build_service.resolver, 'system_resolver', new=resolver):
+            GenericBuilder.clear_cache(self.module)
+            ret = GenericBuilder.default_buildroot_groups(db.session, self.module)
+            assert ret == expected_groups
+            resolver.resolve_profiles.assert_called_once()
 
     def test_get_build_weights(self):
         weights = GenericBuilder.get_build_weights(["httpd", "apr"])

tests/test_scheduler/test_module_wait.py

@@ -27,6 +27,7 @@ import module_build_service.scheduler.handlers.modules
 import os
 import koji
 from tests import conf, db, app, scheduler_init_data
+import module_build_service.resolver
 from module_build_service import build_logs, Modulemd
 from module_build_service.models import ComponentBuild, ModuleBuild
 
@@ -48,8 +49,7 @@ class TestModuleWait:
 
     @patch('module_build_service.builder.GenericBuilder.create_from_module')
     @patch('module_build_service.models.ModuleBuild.from_module_event')
-    @patch('module_build_service.resolver.GenericResolver')
-    def test_init_basic(self, resolver, from_module_event, create_builder):
+    def test_init_basic(self, from_module_event, create_builder):
         builder = mock.Mock()
         builder.get_disttag_srpm.return_value = 'some srpm disttag'
         builder.build.return_value = 1234, 1, "", None
@@ -82,7 +82,8 @@ class TestModuleWait:
 
         msg = module_build_service.messaging.MBSModule(msg_id=None, module_build_id=1,
                                                        module_build_state='some state')
-        self.fn(config=self.config, session=self.session, msg=msg)
+        with patch.object(module_build_service.resolver, 'system_resolver'):
+            self.fn(config=self.config, session=self.session, msg=msg)
 
     @patch("module_build_service.builder.GenericBuilder.default_buildroot_groups",
            return_value={'build': [], 'srpm-build': []})
@@ -112,13 +113,13 @@ class TestModuleWait:
             resolver = mock.MagicMock()
             resolver.backend = 'db'
             resolver.get_module_tag.return_value = "module-testmodule-master-20170109091357"
-            generic_resolver.create.return_value = resolver
 
-            msg = module_build_service.messaging.MBSModule(msg_id=None, module_build_id=2,
-                                                           module_build_state='some state')
-            module_build_service.scheduler.handlers.modules.wait(
-                config=conf, session=db.session, msg=msg)
-            koji_session.newRepo.assert_called_once_with("module-123-build")
+            with patch.object(module_build_service.resolver, 'system_resolver', new=resolver):
+                msg = module_build_service.messaging.MBSModule(msg_id=None, module_build_id=2,
+                                                               module_build_state='some state')
+                module_build_service.scheduler.handlers.modules.wait(
+                    config=conf, session=db.session, msg=msg)
+                koji_session.newRepo.assert_called_once_with("module-123-build")
 
             # When module-build-macros is reused, it still has to appear only
             # once in database.
@@ -154,13 +155,13 @@ class TestModuleWait:
             resolver = mock.MagicMock()
             resolver.backend = 'db'
             resolver.get_module_tag.return_value = "module-testmodule-master-20170109091357"
-            generic_resolver.create.return_value = resolver
 
-            msg = module_build_service.messaging.MBSModule(msg_id=None, module_build_id=2,
-                                                           module_build_state='some state')
-            module_build_service.scheduler.handlers.modules.wait(
-                config=conf, session=db.session, msg=msg)
-            assert koji_session.newRepo.called
+            with patch.object(module_build_service.resolver, 'system_resolver', new=resolver):
+                msg = module_build_service.messaging.MBSModule(msg_id=None, module_build_id=2,
+                                                               module_build_state='some state')
+                module_build_service.scheduler.handlers.modules.wait(
+                    config=conf, session=db.session, msg=msg)
+                assert koji_session.newRepo.called
 
     @patch("module_build_service.builder.GenericBuilder.default_buildroot_groups",
            return_value={'build': [], 'srpm-build': []})
@@ -196,14 +197,14 @@ class TestModuleWait:
             resolver.get_module_tag.return_value = "module-testmodule-master-20170109091357"
             resolver.get_module_build_dependencies.return_value = {
                 "module-bootstrap-tag": base_mmd}
-            generic_resolver.create.return_value = resolver
 
-            msg = module_build_service.messaging.MBSModule(msg_id=None, module_build_id=2,
-                                                           module_build_state='some state')
-            module_build_service.scheduler.handlers.modules.wait(
-                config=conf, session=db.session, msg=msg)
-            module_build = ModuleBuild.query.filter_by(id=2).one()
-            assert module_build.cg_build_koji_tag == "modular-updates-candidate"
+            with patch.object(module_build_service.resolver, 'system_resolver', new=resolver):
+                msg = module_build_service.messaging.MBSModule(msg_id=None, module_build_id=2,
+                                                               module_build_state='some state')
+                module_build_service.scheduler.handlers.modules.wait(
+                    config=conf, session=db.session, msg=msg)
+                module_build = ModuleBuild.query.filter_by(id=2).one()
+                assert module_build.cg_build_koji_tag == "modular-updates-candidate"
 
     @patch("module_build_service.builder.GenericBuilder.default_buildroot_groups",
            return_value={'build': [], 'srpm-build': []})
@@ -241,11 +242,11 @@ class TestModuleWait:
             resolver.get_module_tag.return_value = "module-testmodule-master-20170109091357"
             resolver.get_module_build_dependencies.return_value = {
                 "module-bootstrap-tag": base_mmd}
-            generic_resolver.create.return_value = resolver
 
-            msg = module_build_service.messaging.MBSModule(msg_id=None, module_build_id=2,
-                                                           module_build_state='some state')
-            module_build_service.scheduler.handlers.modules.wait(
-                config=conf, session=db.session, msg=msg)
-            module_build = ModuleBuild.query.filter_by(id=2).one()
-            assert module_build.cg_build_koji_tag == "f27-modular-updates-candidate"
+            with patch.object(module_build_service.resolver, 'system_resolver', new=resolver):
+                msg = module_build_service.messaging.MBSModule(msg_id=None, module_build_id=2,
+                                                               module_build_state='some state')
+                module_build_service.scheduler.handlers.modules.wait(
+                    config=conf, session=db.session, msg=msg)
+                module_build = ModuleBuild.query.filter_by(id=2).one()
+                assert module_build.cg_build_koji_tag == "f27-modular-updates-candidate"