This patch adds support for working with instances by UUID in addition to integer IDs.

The Zone Scheduler routing mechanics were changed slightly so that when an UUID is passed in, it checks to see whether the item is available locally.

If it isn't it re-routes to a child zone. 

If it is available locally, it substitutes the UUID with the integer ID and calls the wrapped function. This is the 'trick' allows us to not change any of the virt-layer code-- everything still uses integer IDs locally.

3 files changed, 115 insertions, 9 deletions

diff --git a/nova/tests/api/openstack/test_servers.py b/nova/tests/api/openstack/test_servers.py
index 8357df594..05de6e2a9 100644
--- a/nova/tests/api/openstack/test_servers.py
+++ b/nova/tests/api/openstack/test_servers.py
@@ -49,10 +49,22 @@ FLAGS = flags.FLAGS
 FLAGS.verbose = True
 
 
-def return_server(context, id):
+FAKE_UUID = 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa'
+
+
+def fake_gen_uuid():
+    return FAKE_UUID
+
+
+def return_server_by_id(context, id):
     return stub_instance(id)
 
 
+def return_server_by_uuid(context, uuid):
+    id = 1
+    return stub_instance(id, uuid=uuid)
+
+
 def return_server_with_addresses(private, public):
     def _return_server(context, id):
         return stub_instance(id, private_address=private,
@@ -111,7 +123,8 @@ def instance_address(context, instance_id):
 
 
 def stub_instance(id, user_id=1, private_address=None, public_addresses=None,
-                  host=None, power_state=0, reservation_id=""):
+                  host=None, power_state=0, reservation_id="",
+                  uuid=FAKE_UUID):
     metadata = []
     metadata.append(InstanceMetadata(key='seq', value=id))
 
@@ -129,7 +142,7 @@ def stub_instance(id, user_id=1, private_address=None, public_addresses=None,
         server_name = "reservation_%s" % (reservation_id, )
 
     instance = {
-        "id": id,
+        "id": int(id),
         "admin_pass": "",
         "user_id": user_id,
         "project_id": "",
@@ -157,7 +170,8 @@ def stub_instance(id, user_id=1, private_address=None, public_addresses=None,
         "display_name": server_name,
         "display_description": "",
         "locked": False,
-        "metadata": metadata}
+        "metadata": metadata,
+        "uuid": uuid}
 
     instance["fixed_ip"] = {
         "address": private_address,
@@ -196,8 +210,11 @@ class ServersTest(test.TestCase):
         fakes.stub_out_auth(self.stubs)
         fakes.stub_out_key_pair_funcs(self.stubs)
         fakes.stub_out_image_service(self.stubs)
+        self.stubs.Set(utils, 'gen_uuid', fake_gen_uuid)
         self.stubs.Set(nova.db.api, 'instance_get_all', return_servers)
-        self.stubs.Set(nova.db.api, 'instance_get', return_server)
+        self.stubs.Set(nova.db.api, 'instance_get', return_server_by_id)
+        self.stubs.Set(nova.db, 'instance_get_by_uuid',
+                       return_server_by_uuid)
         self.stubs.Set(nova.db.api, 'instance_get_all_by_user',
                        return_servers)
         self.stubs.Set(nova.db.api, 'instance_add_security_group',
@@ -229,6 +246,36 @@ class ServersTest(test.TestCase):
         self.assertEqual(res_dict['server']['id'], 1)
         self.assertEqual(res_dict['server']['name'], 'server1')
 
+    def test_get_server_by_uuid(self):
+        """
+        The steps involved with resolving a UUID are pretty complicated;
+        here's what's happening in this scenario:
+
+        1. Show is calling `routing_get`
+
+        2. `routing_get` is wrapped by `reroute_compute` which does the work
+           of resolving requests to child zones.
+
+        3. `reroute_compute` looks up the UUID by hitting the stub
+           (returns_server_by_uuid)
+
+        4. Since the stub return that the record exists, `reroute_compute`
+           considers the request to be 'zone local', so it replaces the UUID
+           in the argument list with an integer ID and then calls the inner
+           function ('get').
+
+        5. The call to `get` hits the other stub 'returns_server_by_id` which
+           has the UUID set to FAKE_UUID
+
+        So, counterintuitively, we call `get` twice on the `show` command.
+        """
+        req = webob.Request.blank('/v1.0/servers/%s' % FAKE_UUID)
+        res = req.get_response(fakes.wsgi_app())
+        res_dict = json.loads(res.body)
+        self.assertEqual(res_dict['server']['id'], 1)
+        self.assertEqual(res_dict['server']['uuid'], FAKE_UUID)
+        self.assertEqual(res_dict['server']['name'], 'server1')
+
     def test_get_server_by_id_v1_1(self):
         req = webob.Request.blank('/v1.1/servers/1')
         res = req.get_response(fakes.wsgi_app())
@@ -540,7 +587,8 @@ class ServersTest(test.TestCase):
     def _setup_for_create_instance(self):
         """Shared implementation for tests below that create instance"""
         def instance_create(context, inst):
-            return {'id': '1', 'display_name': 'server_test'}
+            return {'id': 1, 'display_name': 'server_test',
+                    'uuid': FAKE_UUID}
 
         def server_update(context, id, params):
             return instance_create(context, id)
@@ -594,11 +642,22 @@ class ServersTest(test.TestCase):
         self.assertEqual(1, server['id'])
         self.assertEqual(2, server['flavorId'])
         self.assertEqual(3, server['imageId'])
+        self.assertEqual(FAKE_UUID, server['uuid'])
         self.assertEqual(res.status_int, 200)
 
     def test_create_instance(self):
         self._test_create_instance_helper()
 
+    def test_create_instance_has_uuid(self):
+        """Tests at the db-layer instead of API layer since that's where the
+           UUID is generated
+        """
+        ctxt = context.RequestContext(1, 1)
+        values = {}
+        instance = nova.db.api.instance_create(ctxt, values)
+        expected = FAKE_UUID
+        self.assertEqual(instance['uuid'], expected)
+
     def test_create_instance_via_zones(self):
         """Server generated ReservationID"""
         self._setup_for_create_instance()
@@ -1850,7 +1909,8 @@ class TestServerInstanceCreation(test.TestCase):
                     self.injected_files = kwargs['injected_files']
                 else:
                     self.injected_files = None
-                return [{'id': '1234', 'display_name': 'fakeinstance'}]
+                return [{'id': '1234', 'display_name': 'fakeinstance',
+                         'uuid': FAKE_UUID}]
 
             def set_admin_password(self, *args, **kwargs):
                 pass
diff --git a/nova/tests/scheduler/test_scheduler.py b/nova/tests/scheduler/test_scheduler.py
index 0d7929996..4be59d411 100644
--- a/nova/tests/scheduler/test_scheduler.py
+++ b/nova/tests/scheduler/test_scheduler.py
@@ -48,6 +48,10 @@ flags.DECLARE('stub_network', 'nova.compute.manager')
 flags.DECLARE('instances_path', 'nova.compute.manager')
 
 
+FAKE_UUID_NOT_FOUND = 'ffffffff-ffff-ffff-ffff-ffffffffffff'
+FAKE_UUID = 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa'
+
+
 class TestDriver(driver.Scheduler):
     """Scheduler Driver for Tests"""
     def schedule(context, topic, *args, **kwargs):
@@ -926,12 +930,23 @@ def zone_get_all(context):
            ]
 
 
+def fake_instance_get_by_uuid(context, uuid):
+    if FAKE_UUID_NOT_FOUND:
+        raise exception.InstanceNotFound(instance_id=uuid)
+    else:
+        return {'id': 1}
+
+
 class FakeRerouteCompute(api.reroute_compute):
+    def __init__(self, method_name, id_to_return=1):
+        super(FakeRerouteCompute, self).__init__(method_name)
+        self.id_to_return = id_to_return
+
     def _call_child_zones(self, zones, function):
         return []
 
     def get_collection_context_and_id(self, args, kwargs):
-        return ("servers", None, 1)
+        return ("servers", None, self.id_to_return)
 
     def unmarshall_result(self, zone_responses):
         return dict(magic="found me")
@@ -960,6 +975,8 @@ class ZoneRedirectTest(test.TestCase):
         self.stubs = stubout.StubOutForTesting()
 
         self.stubs.Set(db, 'zone_get_all', zone_get_all)
+        self.stubs.Set(db, 'instance_get_by_uuid',
+                       fake_instance_get_by_uuid)
 
         self.enable_zone_routing = FLAGS.enable_zone_routing
         FLAGS.enable_zone_routing = True
@@ -976,8 +993,19 @@ class ZoneRedirectTest(test.TestCase):
         except api.RedirectResult, e:
             self.fail(_("Successful database hit should succeed"))
 
-    def test_trap_not_found_locally(self):
+    def test_trap_not_found_locally_id_passed(self):
+        """When an integer ID is not found locally, we cannot reroute to
+        another zone, so just return InstanceNotFound exception
+        """
         decorator = FakeRerouteCompute("foo")
+        self.assertRaises(exception.InstanceNotFound,
+            decorator(go_boom), None, None, 1)
+
+    def test_trap_not_found_locally_uuid_passed(self):
+        """When a UUID is found, if the item isn't found locally, we should
+        try to reroute to a child zone to see if they have it
+        """
+        decorator = FakeRerouteCompute("foo", id_to_return=FAKE_UUID_NOT_FOUND)
         try:
             result = decorator(go_boom)(None, None, 1)
             self.assertFail(_("Should have rerouted."))
diff --git a/nova/tests/test_utils.py b/nova/tests/test_utils.py
index 8f7e83c3e..3a3f914e4 100644
--- a/nova/tests/test_utils.py
+++ b/nova/tests/test_utils.py
@@ -275,3 +275,21 @@ class GenericUtilsTestCase(test.TestCase):
         # error case
         result = utils.parse_server_string('www.exa:mple.com:8443')
         self.assertEqual(('', ''), result)
+
+
+class IsUUIDLikeTestCase(test.TestCase):
+    def assertUUIDLike(self, val, expected):
+        result = utils.is_uuid_like(val)
+        self.assertEqual(result, expected)
+
+    def test_good_uuid(self):
+        val = 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa'
+        self.assertUUIDLike(val, True)
+
+    def test_integer_passed(self):
+        val = 1
+        self.assertUUIDLike(val, False)
+
+    def test_non_uuid_string_passed(self):
+        val = 'foo-fooo'
+        self.assertUUIDLike(val, False)