From 6e525647f608839890a8a00a8e03a540a1891471 Mon Sep 17 00:00:00 2001
From: Abhishek Kekane <akekane@redhat.com>
Date: Wed, 21 Aug 2019 10:38:14 +0000
Subject: [PATCH] Fix INSTR not supported for postgresql

Migration script 'train_migrate01_backend_to_store.py' doesn't support
INSTR function for postgresql database. INSTR function does support
sqlite3 and mysql.

Used 'POSITION' function instead of 'INSTR' function if database is
postgresql.
Closes-Bug: #1840898

Change-Id: I62c592f0885927b873ed35a1efe4a0f8407e7dee
---
 .../train_migrate01_backend_to_store.py             | 13 +++++++++++++
 .../db/migrations/test_train_migrate01.py           | 11 ++++++++++-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/glance/db/sqlalchemy/alembic_migrations/data_migrations/train_migrate01_backend_to_store.py b/glance/db/sqlalchemy/alembic_migrations/data_migrations/train_migrate01_backend_to_store.py
index cfb2b82088..ab777b69cf 100644
--- a/glance/db/sqlalchemy/alembic_migrations/data_migrations/train_migrate01_backend_to_store.py
+++ b/glance/db/sqlalchemy/alembic_migrations/data_migrations/train_migrate01_backend_to_store.py
@@ -24,6 +24,12 @@ def has_migrations(engine):
     """
     sql_query = ("select meta_data from image_locations where "
                  "INSTR(meta_data, '\"backend\":') > 0")
+
+    # NOTE(abhishekk): INSTR function doesn't supported in postgresql
+    if engine.name == 'postgresql':
+        sql_query = ("select meta_data from image_locations where "
+                     "POSITION('\"backend\":' IN meta_data) > 0")
+
     with engine.connect() as con:
         metadata_backend = con.execute(sql_query)
         if metadata_backend.rowcount > 0:
@@ -37,6 +43,13 @@ def migrate(engine):
     sql_query = ("UPDATE image_locations SET meta_data = REPLACE(meta_data, "
                  "'\"backend\":', '\"store\":') where INSTR(meta_data, "
                  " '\"backend\":') > 0")
+
+    # NOTE(abhishekk): INSTR function doesn't supported in postgresql
+    if engine.name == 'postgresql':
+        sql_query = ("UPDATE image_locations SET meta_data = REPLACE("
+                     "meta_data, '\"backend\":', '\"store\":') where "
+                     "POSITION('\"backend\":' IN meta_data) > 0")
+
     with engine.connect() as con:
         migrated_rows = con.execute(sql_query)
         return migrated_rows.rowcount
diff --git a/glance/tests/functional/db/migrations/test_train_migrate01.py b/glance/tests/functional/db/migrations/test_train_migrate01.py
index 6d13eb753c..8cfbf55128 100644
--- a/glance/tests/functional/db/migrations/test_train_migrate01.py
+++ b/glance/tests/functional/db/migrations/test_train_migrate01.py
@@ -99,6 +99,11 @@ class TestTrainMigrate01MySQL(TestTrainMigrate01Mixin,
     pass
 
 
+class TestTrain01PostgresSQL(TestTrainMigrate01Mixin,
+                             test_base.PostgreSQLOpportunisticTestCase):
+    pass
+
+
 class TestTrainMigrate01_EmptyDBMixin(test_migrations.AlembicMigrationsMixin):
     """This mixin is used to create an initial glance database and upgrade it
     up to the train_expand01 revision.
@@ -127,5 +132,9 @@ class TestTrainMigrate01_EmptyDBMixin(test_migrations.AlembicMigrationsMixin):
 
 class TestTrainMigrate01_EmptyDBMySQL(TestTrainMigrate01_EmptyDBMixin,
                                       test_base.MySQLOpportunisticTestCase):
-    """This test runs the Train data migrations on an empty databse."""
+    pass
+
+
+class TestTrainMigrate01_PySQL(TestTrainMigrate01_EmptyDBMixin,
+                               test_base.PostgreSQLOpportunisticTestCase):
     pass