Support cinder multiple stores

This patch updates the location URL of the legacy images while
upgrading from single cinder store to multiple stores.
It does that with the help of lazy loading logic i.e. while
GET images call, it checks the location URL and metadata
of the image against the configured store ids and updates
images to respective stores on the basis of volume type (comparing
image-volume's type with the configured cinder_volume_type).
Legacy image URL:
cinder://<volume-id>
New image URL:
cinder://<store-id>/<volume-id>

NOTE: bumping lower-constraints/requirements of glance-store to 2.3.0 as
it includes changes[1] that are a hard requirement for cinder multiple
stores to work with glance

[1] https://review.opendev.org/#/c/746556/

Change-Id: I087a89c20813378fea8ff22ddf81d7a10c220db3
Implements: blueprint multiple-cinder-backend-support

glance/api/authorization.py

@@ -35,7 +35,7 @@ def lazy_update_store_info(func):
     def wrapped(context, image, image_repo, **kwargs):
         if CONF.enabled_backends:
             store_utils.update_store_in_locations(
-                image, image_repo)
+                context, image, image_repo)
 
         return func(context, image, image_repo, **kwargs)
 

glance/common/store_utils.py

@@ -21,7 +21,7 @@ from oslo_utils import encodeutils
 import six.moves.urllib.parse as urlparse
 
 import glance.db as db_api
-from glance.i18n import _LE
+from glance.i18n import _LE, _LW
 from glance import scrubber
 
 LOG = logging.getLogger(__name__)
@@ -178,11 +178,15 @@ def _get_store_id_from_uri(uri):
         return
 
 
-def update_store_in_locations(image, image_repo):
+def update_store_in_locations(context, image, image_repo):
+    store_updated = False
     for loc in image.locations:
         if (not loc['metadata'].get(
                 'store') or loc['metadata'].get(
                 'store') not in CONF.enabled_backends):
+            if loc['url'].startswith("cinder://"):
+                _update_cinder_location_and_store_id(context, loc)
+
             store_id = _get_store_id_from_uri(loc['url'])
             if store_id:
                 if 'store' in loc['metadata']:
@@ -195,8 +199,43 @@ def update_store_in_locations(image, image_repo):
                                                'new': store_id,
                                                'id': image.image_id})
 
+                store_updated = True
                 loc['metadata']['store'] = store_id
-                image_repo.save(image)
+
+    if store_updated:
+        image_repo.save(image)
+
+
+def _update_cinder_location_and_store_id(context, loc):
+    """Update store location of legacy images
+
+    While upgrading from single cinder store to multiple stores,
+    the images having a store configured with a volume type matching
+    the image-volume's type will be migrated/associated to that store
+    and their location url will be updated respectively to the new format
+    i.e. cinder://store-id/volume-id
+    If there is no store configured for the image, the location url will
+    not be updated.
+    """
+    uri = loc['url']
+    volume_id = loc['url'].split("/")[-1]
+    scheme = urlparse.urlparse(uri).scheme
+    location_map = store_api.location.SCHEME_TO_CLS_BACKEND_MAP
+    if scheme not in location_map:
+        LOG.warning(_LW("Unknown scheme '%(scheme)s' found in uri '%(uri)s'"),
+                    {'scheme': scheme, 'uri': uri})
+        return
+
+    for store in location_map[scheme]:
+        store_instance = location_map[scheme][store]['store']
+        if store_instance.is_image_associated_with_store(context, volume_id):
+            url_prefix = store_instance.url_prefix
+            loc['url'] = "%s/%s" % (url_prefix, volume_id)
+            loc['metadata']['store'] = "%s" % store
+            return
+
+    LOG.warning(_LW("Not able to update location url '%s' of legacy image "
+                    "due to unknown issues."), uri)
 
 
 def get_updated_store_location(locations):

glance/tests/unit/base.py

@@ -71,7 +71,8 @@ class MultiStoreClearingUnitTest(test_utils.BaseTestCase):
         :returns: the number of how many store drivers been loaded.
         """
         self.config(enabled_backends={'fast': 'file', 'cheap': 'file',
-                                      'readonly_store': 'http'})
+                                      'readonly_store': 'http',
+                                      'fast-cinder': 'cinder'})
         store.register_store_opts(CONF)
 
         self.config(default_backend='fast',

glance/tests/unit/common/test_utils.py

@@ -14,10 +14,11 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import glance_store as store
 import tempfile
 from unittest import mock
 
+import glance_store as store
+from glance_store._drivers import cinder
 from oslo_config import cfg
 from oslo_log import log as logging
 import six
@@ -26,6 +27,7 @@ import webob
 from glance.common import exception
 from glance.common import store_utils
 from glance.common import utils
+from glance.tests.unit import base
 from glance.tests import utils as test_utils
 
 
@@ -41,6 +43,7 @@ class TestStoreUtils(test_utils.BaseTestCase):
         image = mock.Mock()
         image_repo = mock.Mock()
         image_repo.save = mock.Mock()
+        context = mock.Mock()
         locations = [{
             'url': 'rbd://aaaaaaaa/images/id',
             'metadata': metadata
@@ -49,7 +52,7 @@ class TestStoreUtils(test_utils.BaseTestCase):
         with mock.patch.object(
                 store_utils, '_get_store_id_from_uri') as mock_get_store_id:
             mock_get_store_id.return_value = store_id
-            store_utils.update_store_in_locations(image, image_repo)
+            store_utils.update_store_in_locations(context, image, image_repo)
             self.assertEqual(image.locations[0]['metadata'].get(
                 'store'), expected)
             self.assertEqual(store_id_call_count, mock_get_store_id.call_count)
@@ -92,6 +95,64 @@ class TestStoreUtils(test_utils.BaseTestCase):
                                             save_call_count=0)
 
 
+class TestCinderStoreUtils(base.MultiStoreClearingUnitTest):
+    """Test glance.common.store_utils module for cinder multistore"""
+
+    @mock.patch.object(cinder.Store, 'is_image_associated_with_store')
+    @mock.patch.object(cinder.Store, 'url_prefix',
+                       new_callable=mock.PropertyMock)
+    def _test_update_cinder_store_in_location(self, mock_url_prefix,
+                                              mock_associate_store,
+                                              is_valid=True):
+        volume_id = 'db457a25-8f16-4b2c-a644-eae8d17fe224'
+        store_id = 'fast-cinder'
+        expected = 'fast-cinder'
+        image = mock.Mock()
+        image_repo = mock.Mock()
+        image_repo.save = mock.Mock()
+        context = mock.Mock()
+        mock_associate_store.return_value = is_valid
+        locations = [{
+            'url': 'cinder://%s' % volume_id,
+            'metadata': {}
+        }]
+        mock_url_prefix.return_value = 'cinder://%s' % store_id
+        image.locations = locations
+        store_utils.update_store_in_locations(context, image, image_repo)
+
+        if is_valid:
+            # This is the case where we found an image that has an
+            # old-style URL which does not include the store name,
+            # but for which we know the corresponding store that
+            # refers to the volume type that backs it. We expect that
+            # the URL should be updated to point to the store/volume from
+            # just a naked pointer to the volume, as was the old
+            # format i.e. this is the case when store is valid and location
+            # url, metadata are updated and image_repo.save is called
+            expected_url = mock_url_prefix.return_value + '/' + volume_id
+            self.assertEqual(expected_url, image.locations[0].get('url'))
+            self.assertEqual(expected, image.locations[0]['metadata'].get(
+                'store'))
+            self.assertEqual(1, image_repo.save.call_count)
+        else:
+            # Here, we've got an image backed by a volume which does
+            # not have a corresponding store specifying the volume_type.
+            # Expect that we leave these alone and do not touch the
+            # location URL since we cannot update it with a valid store i.e.
+            # this is the case when store is invalid and location url,
+            # metadata are not updated and image_repo.save is not called
+            self.assertEqual(locations[0]['url'],
+                             image.locations[0].get('url'))
+            self.assertEqual({}, image.locations[0]['metadata'])
+            self.assertEqual(0, image_repo.save.call_count)
+
+    def test_update_cinder_store_location_valid_type(self):
+        self._test_update_cinder_store_in_location()
+
+    def test_update_cinder_store_location_invalid_type(self):
+        self._test_update_cinder_store_in_location(is_valid=False)
+
+
 class TestUtils(test_utils.BaseTestCase):
     """Test routines in glance.utils"""
 

glance/tests/unit/v2/test_discovery_stores.py

@@ -39,7 +39,7 @@ class TestInfoControllers(base.MultiStoreClearingUnitTest):
                           req)
 
     def test_get_stores(self):
-        available_stores = ['cheap', 'fast', 'readonly_store']
+        available_stores = ['cheap', 'fast', 'readonly_store', 'fast-cinder']
         req = unit_test_utils.get_fake_request()
         output = self.controller.get_stores(req)
         self.assertIn('stores', output)
@@ -48,7 +48,7 @@ class TestInfoControllers(base.MultiStoreClearingUnitTest):
             self.assertIn(stores['id'], available_stores)
 
     def test_get_stores_read_only_store(self):
-        available_stores = ['cheap', 'fast', 'readonly_store']
+        available_stores = ['cheap', 'fast', 'readonly_store', 'fast-cinder']
         req = unit_test_utils.get_fake_request()
         output = self.controller.get_stores(req)
         self.assertIn('stores', output)

lower-constraints.txt

@@ -29,7 +29,7 @@ fasteners==0.14.1
 fixtures==3.0.0
 future==0.16.0
 futurist==1.2.0
-glance-store==1.0.0
+glance-store==2.3.0
 greenlet==0.4.13
 httplib2==0.9.1
 idna==2.6

releasenotes/notes/support-cinder-multiple-stores-eb4e6d912d549ee9.yaml

@@ -0,0 +1,12 @@
+---
+features:
+  - |
+    Added support for cinder multiple stores.
+upgrade:
+  - |
+    During upgrade from single cinder store to multiple cinder stores, legacy
+    images location url will be updated to the new format with respect to the
+    volume type configured in the stores.
+    Legacy location url: cinder://<volume-id>
+    New location url: cinder://<store-id>/<volume-id>
+

requirements.txt

@@ -48,7 +48,7 @@ retrying!=1.3.0,>=1.2.3 # Apache-2.0
 osprofiler>=1.4.0 # Apache-2.0
 
 # Glance Store
-glance-store>=1.0.0 # Apache-2.0
+glance-store>=2.3.0 # Apache-2.0
 
 
 debtcollector>=1.2.0 # Apache-2.0