Migration 147: Prevent duplicate aggregate_hosts

If an aggregate_host record is already present, then the `upgrade`
shouldn't attempt to add it again.

Change-Id: Ib7ab10fa7c166ccaa3df6a96eb08c7ebcd0af38c

2 files changed, 31 insertions, 2 deletions

diff --git a/nova/db/sqlalchemy/migrate_repo/versions/147_no_service_zones.py b/nova/db/sqlalchemy/migrate_repo/versions/147_no_service_zones.py
index d93cd1ead..5c079584d 100644
--- a/nova/db/sqlalchemy/migrate_repo/versions/147_no_service_zones.py
+++ b/nova/db/sqlalchemy/migrate_repo/versions/147_no_service_zones.py
@@ -58,8 +58,12 @@ def upgrade(migrate_engine):
                         })
         # add host to zone
         agg_hosts = Table('aggregate_hosts', meta, autoload=True)
-        row = agg_hosts.insert()
-        row.execute({'host': rec['host'], 'aggregate_id': agg_id})
+        num_hosts = agg_hosts.count().where(
+            agg_hosts.c.host == rec['host']).where(
+            agg_hosts.c.aggregate_id == agg_id).execute().scalar()
+        if num_hosts == 0:
+            agg_hosts.insert().execute({'host': rec['host'],
+                                        'aggregate_id': agg_id})
 
     services.drop_column('availability_zone')
 
diff --git a/nova/tests/test_migrations.py b/nova/tests/test_migrations.py
index 55963a81b..60efcf34f 100644
--- a/nova/tests/test_migrations.py
+++ b/nova/tests/test_migrations.py
@@ -588,8 +588,24 @@ class TestNovaMigrations(BaseMigrationTestCase, CommonTestsMixIn):
 
         services = get_table(engine, 'services')
         engine.execute(services.insert(), data)
+        self._pre_upgrade_147_no_duplicate_aggregate_hosts(engine)
         return data
 
+    def _pre_upgrade_147_no_duplicate_aggregate_hosts(self, engine):
+        engine.execute(get_table(engine, 'aggregate_metadata').insert(), [
+            {'aggregate_id': 1,
+             'key': 'availability_zone',
+             'value': 'custom_az'}])
+
+        engine.execute(get_table(engine, 'aggregate_hosts').insert(), [
+            {'aggregate_id': 1,
+             'host': 'compute-host3'}])
+
+        engine.execute(get_table(engine, 'services').insert(), [
+            {'id': 99, 'host': 'compute-host3',
+             'binary': 'nova-compute', 'topic': 'compute',
+             'report_count': 0, 'availability_zone': 'custom_az'}])
+
     def _check_147(self, engine, data):
         aggregate_md = get_table(engine, 'aggregate_metadata')
         aggregate_hosts = get_table(engine, 'aggregate_hosts')
@@ -612,6 +628,15 @@ class TestNovaMigrations(BaseMigrationTestCase, CommonTestsMixIn):
             ).execute().first()
         self.assertEqual(host, None)
 
+        self._check_147_no_duplicate_aggregate_hosts(engine, data)
+
+    def _check_147_no_duplicate_aggregate_hosts(self, engine, data):
+        aggregate_hosts = get_table(engine, 'aggregate_hosts')
+        agg1_hosts = [h['host'] for h in aggregate_hosts.select(
+            aggregate_hosts.c.aggregate_id == 1
+            ).execute().fetchall()]
+        self.assertEqual(['compute-host3'], agg1_hosts)
+
     # migration 149, changes IPAddr storage format
     def _pre_upgrade_149(self, engine):
         provider_fw_rules = get_table(engine, 'provider_fw_rules')