Sort locations based on store weight

Related to blueprint store-weight

Change-Id: I2383a476cb7e79c7efecdf33203cff0b50ef3bbb

api-ref/source/v2/discovery-parameters.yaml

@@ -37,6 +37,9 @@ stores-detail:
         for more information.)
     ``read-only`` (optional)
         Included only when the store is read only.
+    ``weight`` (default 0)
+        Contains weight (positive integer) to sort image locations for
+        preference.
     ``properties``
         Contains store specific properties
   in: body

api-ref/source/v2/samples/stores-list-detail-response.json

@@ -5,6 +5,7 @@
             "type": "rbd",
             "description": "More expensive store with data redundancy",
             "default": true,
+            "weight": 100,
             "properties": {
                 "pool": "pool1",
                 "chunk_size": 65536,
@@ -15,6 +16,7 @@
             "id":"cheap",
             "type": "file",
             "description": "Less expensive store for seldom-used images",
+            "weight": 200,
             "properties": {
                 "datadir": "fdir",
                 "chunk_size": 65536,
@@ -25,6 +27,7 @@
             "id":"fast",
             "type": "cinder",
             "description": "Reasonably-priced fast store",
+            "weight": 300,
             "properties": {
                 "volume_type": "volume1",
                 "use_multipath": false
@@ -34,6 +37,7 @@
             "id":"slow",
             "type": "swift",
             "description": "Entry-level store balancing price and speed",
+            "weight": 400,
             "properties": {
                 "container": "container1",
                 "large_object_size": 52428,

glance/api/v2/discovery.py

@@ -149,6 +149,7 @@ class InfoController(object):
                     store['id'])
                 store['properties'] = store_mapper.get(store_type)(
                     store_detail)
+                store['weight'] = getattr(CONF, store['id']).weight
 
         except exception.Forbidden as e:
             LOG.debug("User not permitted to view details")

glance/api/v2/images.py

@@ -36,7 +36,6 @@ from glance.api import common
 from glance.api import policy
 from glance.api.v2 import policy as api_policy
 from glance.common import exception
-from glance.common import location_strategy
 from glance.common import store_utils
 from glance.common import timeutils
 from glance.common import utils
@@ -1610,7 +1609,7 @@ class ResponseSerializer(wsgi.JSONResponseSerializer):
                 locations = _get_image_locations(image)
                 if locations:
                     # Choose best location configured strategy
-                    loc = location_strategy.choose_best_location(locations)
+                    loc = utils.sort_image_locations(locations)[0]
                     image_view['direct_url'] = loc['url']
                 else:
                     LOG.debug("The 'locations' list of image %s is empty, "

glance/common/utils.py

@@ -42,9 +42,10 @@ from oslo_utils import strutils
 from webob import exc
 
 from glance.common import exception
+from glance.common import location_strategy
 from glance.common import timeutils
 from glance.common import wsgi
-from glance.i18n import _, _LE
+from glance.i18n import _, _LE, _LW
 
 CONF = cfg.CONF
 
@@ -712,3 +713,25 @@ def get_stores_from_request(req, body):
     for store in stores:
         glance_store.get_store_from_store_identifier(store)
     return stores
+
+
+def sort_image_locations(locations):
+    if not CONF.enabled_backends:
+        return location_strategy.get_ordered_locations(locations)
+
+    def get_store_weight(location):
+        store_id = location['metadata'].get('store')
+        if not store_id:
+            return 0
+        try:
+            store = glance_store.get_store_from_store_identifier(store_id)
+        except glance_store.exceptions.UnknownScheme:
+            msg = (_LW("Unable to find store '%s', returning "
+                       "default weight '0'") % store_id)
+            LOG.warning(msg)
+            return 0
+        return store.weight if store is not None else 0
+
+    sorted_locations = sorted(locations, key=get_store_weight, reverse=True)
+    LOG.debug(('Sorted locations: %s'), sorted_locations)
+    return sorted_locations

glance/db/__init__.py

@@ -24,7 +24,7 @@ from wsme.rest import json
 from glance.api.v2.model.metadef_property_type import PropertyType
 from glance.common import crypt
 from glance.common import exception
-from glance.common import location_strategy
+from glance.common import utils as common_utils
 import glance.domain
 import glance.domain.proxy
 from glance.i18n import _
@@ -127,7 +127,7 @@ class ImageRepo(object):
             min_disk=db_image['min_disk'],
             min_ram=db_image['min_ram'],
             protected=db_image['protected'],
-            locations=location_strategy.get_ordered_locations(locations),
+            locations=common_utils.sort_image_locations(locations),
             checksum=db_image['checksum'],
             os_hash_algo=db_image['os_hash_algo'],
             os_hash_value=db_image['os_hash_value'],

glance/tests/functional/v2/test_discovery.py

@@ -131,6 +131,7 @@ class TestDiscovery(functional.SynchronousAPIBase):
                     "id": "store1",
                     "default": "true",
                     "type": "file",
+                    "weight": 0,
                     "properties": {
                           "data_dir": self._store_dir('store1'),
                           "chunk_size": 65536,
@@ -140,6 +141,7 @@ class TestDiscovery(functional.SynchronousAPIBase):
                 {
                     "id": "store2",
                     "type": "file",
+                    "weight": 0,
                     "properties": {
                           "data_dir": self._store_dir('store2'),
                           "chunk_size": 65536,
@@ -149,6 +151,7 @@ class TestDiscovery(functional.SynchronousAPIBase):
                 {
                     "id": "store3",
                     "type": "file",
+                    "weight": 0,
                     "properties": {
                           "data_dir": self._store_dir('store3'),
                           "chunk_size": 65536,

glance/tests/functional/v2/test_images.py

@@ -7318,3 +7318,38 @@ class TestKeystoneQuotas(functional.SynchronousAPIBase):
 
         # Make sure we can still import.
         self._create_and_import(stores=['store1'])
+
+
+class TestStoreWeight(functional.SynchronousAPIBase):
+    def setUp(self):
+        super(TestStoreWeight, self).setUp()
+
+    def test_store_weight_combinations(self):
+        self.start_server()
+        # Import image in all available stores
+        image_id = self._create_and_import(stores=['store1', 'store2',
+                                                   'store3'])
+        # make sure as weight is default, we will get locations based
+        # on insertion order
+        image = self.api_get('/v2/images/%s' % image_id).json
+        self.assertEqual("store1,store2,store3", image['stores'])
+
+        # give highest weight to store2 then store3 and then store1
+        self.config(weight=200, group='store2')
+        self.config(weight=100, group='store3')
+        self.config(weight=50, group='store1')
+        self.start_server()
+        # make sure as per store weight locations will be sorted
+        # as store2,store3,store1
+        image = self.api_get('/v2/images/%s' % image_id).json
+        self.assertEqual("store2,store3,store1", image['stores'])
+
+        # give highest weight to store3 then store1 and then store2
+        self.config(weight=20, group='store2')
+        self.config(weight=100, group='store3')
+        self.config(weight=50, group='store1')
+        self.start_server()
+        # make sure as per store weight locations will be sorted
+        # as store3,store1,store2
+        image = self.api_get('/v2/images/%s' % image_id).json
+        self.assertEqual("store3,store1,store2", image['stores'])

glance/tests/unit/common/test_utils.py

@@ -155,6 +155,139 @@ class TestCinderStoreUtils(base.MultiStoreClearingUnitTest):
 class TestUtils(test_utils.BaseTestCase):
     """Test routines in glance.utils"""
 
+    def test_sort_image_locations_multistore_disabled(self):
+        self.config(enabled_backends=None)
+        locations = [{
+            'url': 'rbd://aaaaaaaa/images/id',
+            'metadata': {'store': 'rbd1'}
+        }, {
+            'url': 'rbd://bbbbbbbb/images/id',
+            'metadata': {'store': 'rbd2'}
+        }, {
+            'url': 'rbd://cccccccc/images/id',
+            'metadata': {'store': 'rbd3'}
+        }]
+        mp = "glance.common.utils.glance_store.get_store_from_store_identifier"
+        with mock.patch(mp) as mock_get_store:
+            utils.sort_image_locations(locations)
+
+        # Since multistore is not enabled, it will not sort the locations
+        self.assertEqual(0, mock_get_store.call_count)
+
+    def test_sort_image_locations(self):
+        enabled_backends = {
+            "rbd1": "rbd",
+            "rbd2": "rbd",
+            "rbd3": "rbd"
+        }
+        self.config(enabled_backends=enabled_backends)
+        store.register_store_opts(CONF)
+        self.config(default_backend="rbd1", group="glance_store")
+        locations = [{
+            'url': 'rbd://aaaaaaaa/images/id',
+            'metadata': {'store': 'rbd1'}
+        }, {
+            'url': 'rbd://bbbbbbbb/images/id',
+            'metadata': {'store': 'rbd2'}
+        }, {
+            'url': 'rbd://cccccccc/images/id',
+            'metadata': {'store': 'rbd3'}
+        }]
+        mp = "glance.common.utils.glance_store.get_store_from_store_identifier"
+        with mock.patch(mp) as mock_get_store:
+            mock_store = mock_get_store.return_value
+            mock_store.weight = 100
+            utils.sort_image_locations(locations)
+
+        # Since 3 stores are configured, internal method will be called 3 times
+        self.assertEqual(3, mock_get_store.call_count)
+
+    def test_sort_image_locations_without_metadata(self):
+        enabled_backends = {
+            "rbd1": "rbd",
+            "rbd2": "rbd",
+            "rbd3": "rbd"
+        }
+        self.config(enabled_backends=enabled_backends)
+        store.register_store_opts(CONF)
+        self.config(default_backend="rbd1", group="glance_store")
+        locations = [{
+            'url': 'rbd://aaaaaaaa/images/id',
+            'metadata': {}
+        }, {
+            'url': 'rbd://bbbbbbbb/images/id',
+            'metadata': {}
+        }, {
+            'url': 'rbd://cccccccc/images/id',
+            'metadata': {}
+        }]
+        mp = "glance.common.utils.glance_store.get_store_from_store_identifier"
+        with mock.patch(mp) as mock_get_store:
+            utils.sort_image_locations(locations)
+
+        # Since 3 stores are configured, without store in metadata the internal
+        # method will be called 0 times
+        self.assertEqual(0, mock_get_store.call_count)
+
+    def test_sort_image_locations_with_partial_metadata(self):
+        enabled_backends = {
+            "rbd1": "rbd",
+            "rbd2": "rbd",
+            "rbd3": "rbd"
+        }
+        self.config(enabled_backends=enabled_backends)
+        store.register_store_opts(CONF)
+        self.config(default_backend="rbd1", group="glance_store")
+        locations = [{
+            'url': 'rbd://aaaaaaaa/images/id',
+            'metadata': {'store': 'rbd1'}
+        }, {
+            'url': 'rbd://bbbbbbbb/images/id',
+            'metadata': {}
+        }, {
+            'url': 'rbd://cccccccc/images/id',
+            'metadata': {}
+        }]
+        mp = "glance.common.utils.glance_store.get_store_from_store_identifier"
+        with mock.patch(mp) as mock_get_store:
+            mock_store = mock_get_store.return_value
+            mock_store.weight = 100
+            utils.sort_image_locations(locations)
+
+        # Since 3 stores are configured, but only one location has
+        # store in metadata the internal
+        # method will be called 1 time only
+        self.assertEqual(1, mock_get_store.call_count)
+
+    def test_sort_image_locations_unknownscheme(self):
+        enabled_backends = {
+            "rbd1": "rbd",
+            "rbd2": "rbd",
+            "rbd3": "rbd"
+        }
+        self.config(enabled_backends=enabled_backends)
+        store.register_store_opts(CONF)
+        self.config(default_backend="rbd1", group="glance_store")
+        locations = [{
+            'url': 'rbd://aaaaaaaa/images/id',
+            'metadata': {'store': 'rbd1'}
+        }, {
+            'url': 'rbd://bbbbbbbb/images/id',
+            'metadata': {'store': 'rbd2'}
+        }, {
+            'url': 'rbd://cccccccc/images/id',
+            'metadata': {'store': 'rbd3'}
+        }]
+        mp = "glance.common.utils.glance_store.get_store_from_store_identifier"
+        with mock.patch(mp) as mock_get_store:
+            mock_get_store.side_effect = store.UnknownScheme()
+            sorted_locations = utils.sort_image_locations(locations)
+
+        # Even though UnknownScheme exception is raised, processing continues
+        self.assertEqual(3, mock_get_store.call_count)
+        # Since we return 0 weight, original location order should be preserved
+        self.assertEqual(locations, sorted_locations)
+
     def test_cooperative_reader(self):
         """Ensure cooperative reader class accesses all bytes of file"""
         BYTES = 1024

glance/tests/unit/v2/test_discovery_stores.py

@@ -46,6 +46,7 @@ class TestInfoControllers(base.MultiStoreClearingUnitTest):
         self.assertIn('stores', output)
         for stores in output['stores']:
             self.assertIn('id', stores)
+            self.assertNotIn('weight', stores)
             self.assertIn(stores['id'], available_stores)
 
     def test_get_stores_read_only_store(self):
@@ -108,6 +109,20 @@ class TestInfoControllers(base.MultiStoreClearingUnitTest):
             expected_attribute = store_attributes[store['type']]
             self.assertEqual(actual_attribute, expected_attribute)
 
+    def test_get_stores_detail_with_store_weight(self):
+        self.config(weight=100, group='fast')
+        self.config(weight=200, group='cheap')
+        self.config(weight=300, group='fast-rbd')
+        self.config(weight=400, group='fast-cinder')
+        self.config(weight=500, group='reliable')
+
+        req = unit_test_utils.get_fake_request(roles=['admin'])
+        output = self.controller.get_stores_detail(req)
+        self.assertEqual(len(CONF.enabled_backends), len(output['stores']))
+        self.assertIn('stores', output)
+        for store in output['stores']:
+            self.assertIn('weight', store)
+
     def test_get_stores_detail_non_admin(self):
         req = unit_test_utils.get_fake_request()
         self.assertRaises(webob.exc.HTTPForbidden,

releasenotes/notes/store-weight-3ed3ee612579bc25.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    "GET" images API will now sort image locations based on store weight
+    configured for each store in configuration files. Image will be
+    downloaded from the store having highest weight configured. For default
+    weight scenario the locations will remain same as per insertion order.