diff --git a/nova/tests/test_db_api.py b/nova/tests/test_db_api.py
index ce4c8fe7..23b8ebcb 100644
--- a/nova/tests/test_db_api.py
+++ b/nova/tests/test_db_api.py
@@ -1066,6 +1066,67 @@ class DbApiTestCase(DbTestCase):
         _compare(bw_usages[2], expected_bw_usages[2])
         timeutils.clear_time_override()
 
+    def test_key_pair_create(self):
+        ctxt = context.get_admin_context()
+        values = {'name': 'test_keypair', 'public_key': 'test-public-key',
+                'user_id': 'test_user_id', 'fingerprint': 'test_fingerprint'}
+        keypair = db.key_pair_create(ctxt, values)
+        self.assertNotEqual(None, keypair)
+        for name, value in values.iteritems():
+            self.assertEqual(keypair.get(name), value)
+
+    def test_key_pair_create_with_duplicate_name(self):
+        ctxt = context.get_admin_context()
+        values = {'name': 'test_keypair', 'public_key': 'test-public-key',
+                'user_id': 'test_user_id', 'fingerprint': 'test_fingerprint'}
+        keypair = db.key_pair_create(ctxt, values)
+        self.assertRaises(exception.KeyPairExists,
+                          db.key_pair_create, ctxt, values)
+
+    def test_admin_get_deleted_keypair(self):
+        # Test deleted keypair can be read by admin user.
+        ctxt = context.get_admin_context()
+        values = {'name': 'test_keypair', 'public_key': 'test-public-key',
+                 'user_id': 'test_user_id', 'fingerprint': 'test_fingerprint'}
+        keypair = db.key_pair_create(ctxt, values)
+        db.key_pair_destroy(ctxt, keypair['user_id'], keypair['name'])
+
+        # Raise exception when read_deleted is 'no'.
+        self.assertRaises(exception.KeypairNotFound, db.key_pair_get, ctxt,
+                          keypair['user_id'], keypair['name'])
+        ctxt = ctxt.elevated(read_deleted='yes')
+        db_keypair = db.key_pair_get(ctxt, keypair['user_id'],
+                                     keypair['name'])
+        self.assertEqual(db_keypair['name'], keypair['name'])
+        self.assertEqual(db_keypair['deleted'], keypair['id'])
+
+    def test_admin_get_all_keypairs_including_deleted(self):
+        # Test all deleted/non-deleted keypairs can be read by admin user.
+        ctxt = context.get_admin_context()
+        keypair1_values = {'name': 'test_keypair1',
+                           'public_key': 'test-public-key1',
+                           'user_id': 'test_user_id',
+                           'fingerprint': 'test_fingerprint1'}
+        keypair2_values = {'name': 'test_keypair2',
+                           'public_key': 'test-public-key2',
+                           'user_id': 'test_user_id',
+                           'fingerprint': 'test_fingerprint2'}
+        keypair1 = db.key_pair_create(ctxt, keypair1_values)
+        keypair2 = db.key_pair_create(ctxt, keypair2_values)
+        db.key_pair_destroy(ctxt, keypair1['user_id'], keypair1['name'])
+        db.key_pair_destroy(ctxt, keypair2['user_id'], keypair2['name'])
+        # Returns non-deleted keypairs.
+        result = db.key_pair_get_all_by_user(ctxt, keypair1['user_id'])
+        self.assertEqual(result, [])
+        ctxt = ctxt.elevated(read_deleted='yes')
+        # Returns deleted and non-deleted keypairs.
+        db_keypairs = db.key_pair_get_all_by_user(ctxt, keypair1['user_id'])
+        expected_deleted_ids = [keypair1['id'], keypair2['id']]
+        expected_keypair_names = [keypair1['name'], keypair2['name']]
+        for keypair in db_keypairs:
+            self.assertTrue(keypair['name'] in expected_keypair_names)
+            self.assertTrue(keypair['deleted'] in expected_deleted_ids)
+
 
 def _get_fake_aggr_values():
     return {'name': 'fake_aggregate'}
diff --git a/nova/tests/test_migrations.py b/nova/tests/test_migrations.py
index 98c50aaa..c78bb6d2 100644
--- a/nova/tests/test_migrations.py
+++ b/nova/tests/test_migrations.py
@@ -1151,6 +1151,45 @@ class TestNovaMigrations(BaseMigrationTestCase, CommonTestsMixIn):
                     fetchall()
         self.assertEqual(1, len(uc_name2_rows))
 
+    # migration 173, add unique constraint to keypairs
+    def _pre_upgrade_173(self, engine):
+        created_at = [datetime.datetime.now() for x in range(0, 7)]
+        fake_keypairs = [dict(name='key1', user_id='1a',
+                              created_at=created_at[0],
+                              deleted=0),
+                         dict(name='key1', user_id='1a',
+                              created_at=created_at[1],
+                              deleted=0),
+                         dict(name='key1', user_id='1a',
+                              created_at=created_at[2],
+                              deleted=0)
+                         ]
+        keypairs = get_table(engine, 'key_pairs')
+        engine.execute(keypairs.insert(), fake_keypairs)
+        return fake_keypairs
+
+    def _check_173(self, engine, data):
+        keypairs = get_table(engine, 'key_pairs')
+        # Unique constraints are not listed in table.constraints for any db.
+        # So, simply add a duplicate keypair to check if unique constraint
+        # is applied to the key_pairs table or not.
+        insert = keypairs.insert()
+        duplicate_keypair = dict(name='key4', user_id='4a',
+                        created_at=datetime.datetime.now(),
+                        deleted=0)
+        insert.execute(duplicate_keypair)
+        # Insert again
+        self.assertRaises(sqlalchemy.exc.IntegrityError, insert.execute,
+                          duplicate_keypair)
+
+        # Get all unique records
+        rows = keypairs.select().\
+                     where(keypairs.c.deleted != keypairs.c.id).\
+                     execute().\
+                     fetchall()
+        # Ensure the number of unique keypairs is correct
+        self.assertEqual(len(rows), 2)
+
 
 class TestBaremetalMigrations(BaseMigrationTestCase, CommonTestsMixIn):
     """Test sqlalchemy-migrate migrations."""