Use inspect instead of Inspector.from_engine()

SQLAlchemy is likely going to deprecate
Inspector.from_engine() which will start emitting a deprecation
warning in 1.4.   Use sqlalchemy.inspect() instead.

Change-Id: I287ba10f2e3308950b9caf6f51f3ee1db29a6448

keystone/common/sql/contract_repo/versions/014_contract_add_domain_id_to_user_table.py

@@ -12,7 +12,6 @@
 
 import migrate
 import sqlalchemy as sql
-from sqlalchemy.engine import reflection
 
 from keystone.common.sql import upgrades
 
@@ -20,7 +19,7 @@ from keystone.common.sql import upgrades
 def upgrade(migrate_engine):
     meta = sql.MetaData()
     meta.bind = migrate_engine
-    inspector = reflection.Inspector.from_engine(migrate_engine)
+    inspector = sql.inspect(migrate_engine)
 
     user = sql.Table('user', meta, autoload=True)
     local_user = sql.Table('local_user', meta, autoload=True)

keystone/common/sql/contract_repo/versions/037_contract_remove_service_and_region_fk_for_registered_limit.py

@@ -22,7 +22,7 @@ def upgrade(migrate_engine):
     service_table = sql.Table('service', meta, autoload=True)
     region_table = sql.Table('region', meta, autoload=True)
 
-    inspector = sql.engine.reflection.Inspector.from_engine(migrate_engine)
+    inspector = sql.inspect(migrate_engine)
     for fk in inspector.get_foreign_keys('registered_limit'):
         if fk['referred_table'] == 'service':
             fkey = ForeignKeyConstraint([registered_limit_table.c.service_id],

keystone/common/sql/contract_repo/versions/047_contract_expand_update_pk_for_unified_limit.py

@@ -26,7 +26,7 @@ def upgrade(migrate_engine):
 
     if migrate_engine.name != 'sqlite':
         project_table = sql.Table('project', meta, autoload=True)
-        inspector = sql.engine.reflection.Inspector.from_engine(migrate_engine)
+        inspector = sql.inspect(migrate_engine)
         for fk in inspector.get_foreign_keys('limit'):
             fkey = migrate.ForeignKeyConstraint(
                 [limit_table.c.project_id],

keystone/tests/unit/test_sql_upgrade.py

@@ -56,8 +56,8 @@ from oslo_log import log
 from oslo_serialization import jsonutils
 from oslotest import base as test_base
 import pytz
-from sqlalchemy.engine import reflection
 import sqlalchemy.exc
+from sqlalchemy import inspect
 from testtools import matchers
 
 from keystone.cmd import cli
@@ -312,13 +312,13 @@ class SqlMigrateBase(db_fixtures.OpportunisticDBTestMixin,
 
     def does_pk_exist(self, table, pk_column):
         """Check whether a column is primary key on a table."""
-        inspector = reflection.Inspector.from_engine(self.engine)
+        inspector = inspect(self.engine)
         pk_columns = inspector.get_pk_constraint(table)['constrained_columns']
 
         return pk_column in pk_columns
 
     def does_fk_exist(self, table, fk_column):
-        inspector = reflection.Inspector.from_engine(self.engine)
+        inspector = inspect(self.engine)
         for fk in inspector.get_foreign_keys(table):
             if fk_column in fk['constrained_columns']:
                 return True
@@ -333,7 +333,7 @@ class SqlMigrateBase(db_fixtures.OpportunisticDBTestMixin,
         return index_name in [idx.name for idx in table.indexes]
 
     def does_unique_constraint_exist(self, table_name, column_names):
-        inspector = reflection.Inspector.from_engine(self.engine)
+        inspector = inspect(self.engine)
         constraints = inspector.get_unique_constraints(table_name)
         for c in constraints:
             if (len(c['column_names']) == 1 and
@@ -668,7 +668,7 @@ class SqlLegacyRepoUpgradeTests(SqlMigrateBase):
 
     def test_add_trust_unique_constraint_upgrade(self):
         self.upgrade(86)
-        inspector = reflection.Inspector.from_engine(self.engine)
+        inspector = inspect(self.engine)
         constraints = inspector.get_unique_constraints('trust')
         constraint_names = [constraint['name'] for constraint in constraints]
         self.assertIn('duplicate_trust_constraint', constraint_names)
@@ -701,7 +701,7 @@ class SqlLegacyRepoUpgradeTests(SqlMigrateBase):
         session = self.sessionmaker()
         self.assertTableColumns('role', ['id', 'name', 'domain_id', 'extra'])
         # Check the domain_id has been added to the uniqueness constraint
-        inspector = reflection.Inspector.from_engine(self.engine)
+        inspector = inspect(self.engine)
         constraints = inspector.get_unique_constraints('role')
         constraint_columns = [
             constraint['column_names'] for constraint in constraints

releasenotes/notes/use-correct-inspect-8142e317c1e39c2a.yaml

@@ -0,0 +1,8 @@
+---
+fixes:
+  - >
+    Replaced the usage of SQLAlchemy Inspector.from_engine() with the
+    sqlalchemy.inspect() call, within several Alembic migration files as well
+    as a test suite.   SQLAlchemy will be deprecating the former syntax,
+    so this change allows forwads compatibility with the next series of
+    SQLAlchemy.