Fixing broken credential schema in sqlite.

Credential table has foreign key constraint
referring to tenant table which is dropped.
Since sqlite does not support alter table
drop constraint, the foreign key constraint
was not dropped. When we try to load credential
table using sqlite backend it fails because tenant
table does not exist. Fix is provided such that
the credential table is recreated without foreign
key constraint and the data is moved from old
credential table to the new credential table.

Fixes Bug #1190383

Change-Id: I3afb04254f33e12fccb7da84c8674feba36622c8

1 files changed, 119 insertions, 0 deletions

diff --git a/keystone/common/sql/migrate_repo/versions/030_drop_credential_constraint_sqlite.py b/keystone/common/sql/migrate_repo/versions/030_drop_credential_constraint_sqlite.py
new file mode 100644
index 00000000..27676dcc
--- /dev/null
+++ b/keystone/common/sql/migrate_repo/versions/030_drop_credential_constraint_sqlite.py
@@ -0,0 +1,119 @@
+
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2013 OpenStack LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import sqlalchemy
+from sqlalchemy.orm import sessionmaker
+
+
+def upgrade(migrate_engine):
+    if migrate_engine.name == 'sqlite':
+        drop_credential_table_foreign_key_constraints_for_sqlite(
+            migrate_engine)
+
+
+def downgrade(migrate_engine):
+    if migrate_engine.name == 'sqlite':
+        add_credential_table_foreign_key_constraints_for_sqlite(migrate_engine)
+
+
+def drop_credential_table_foreign_key_constraints_for_sqlite(migrate_engine):
+    meta = sqlalchemy.MetaData()
+    meta.bind = migrate_engine
+
+    # NOTE(nachiappan): SQLite does not support ALTER TABLE DROP constraint.
+    #                   So we need to move the data to new credenital table
+    #                   created without constraints, drop the old table and
+    #                   rename the new table to credential.
+    sqlalchemy.Table('user', meta, autoload=True)
+    tenant_table = sqlalchemy.Table(
+        'tenant',
+        meta,
+        sqlalchemy.Column('id', sqlalchemy.String(64), primary_key=True),
+        sqlalchemy.Column(
+            'name', sqlalchemy.String(64), unique=True, nullable=False),
+        sqlalchemy.Column('extra', sqlalchemy.Text()))
+    tenant_table.create(migrate_engine, checkfirst=True)
+    cred_table = sqlalchemy.Table('credential', meta, autoload=True)
+
+    session = sessionmaker(bind=migrate_engine)()
+    new_credential_table = sqlalchemy.Table(
+        'new_credential',
+        meta,
+        sqlalchemy.Column('id', sqlalchemy.String(64), primary_key=True),
+        sqlalchemy.Column('user_id',
+                          sqlalchemy.String(64),
+                          nullable=False),
+        sqlalchemy.Column('project_id',
+                          sqlalchemy.String(64)),
+        sqlalchemy.Column('blob', sqlalchemy.Text(), nullable=False),
+        sqlalchemy.Column('type', sqlalchemy.String(255), nullable=False),
+        sqlalchemy.Column('extra', sqlalchemy.Text()))
+    new_credential_table.create(migrate_engine, checkfirst=True)
+
+    insert = new_credential_table.insert()
+    for credential in session.query(cred_table):
+        insert.execute({'id': credential.id,
+                        'user_id': credential.user_id,
+                        'project_id': credential.project_id,
+                        'blob': credential.blob,
+                        'type': credential.type,
+                        'extra': credential.extra})
+    cred_table.drop()
+    tenant_table.drop()
+    new_credential_table.rename('credential')
+    session.commit()
+    session.close()
+
+
+def add_credential_table_foreign_key_constraints_for_sqlite(migrate_engine):
+    meta = sqlalchemy.MetaData()
+    meta.bind = migrate_engine
+
+    cred_table = sqlalchemy.Table('credential', meta, autoload=True)
+    sqlalchemy.Table('user', meta, autoload=True)
+
+    session = sessionmaker(bind=migrate_engine)()
+    old_credential_table = sqlalchemy.Table(
+        'old_credential',
+        meta,
+        sqlalchemy.Column('id', sqlalchemy.String(64), primary_key=True),
+        sqlalchemy.Column('user_id',
+                          sqlalchemy.String(64),
+                          sqlalchemy.ForeignKey('user.id'),
+                          nullable=False),
+        # NOTE(nachiappan): Not creating the foreign key constraint with
+        #                   project  table as version 15 conflicts with
+        #                   version 7.
+        sqlalchemy.Column('project_id',
+                          sqlalchemy.String(64)),
+        sqlalchemy.Column('blob', sqlalchemy.Text(), nullable=False),
+        sqlalchemy.Column('type', sqlalchemy.String(255), nullable=False),
+        sqlalchemy.Column('extra', sqlalchemy.Text()))
+    old_credential_table.create(migrate_engine, checkfirst=True)
+
+    insert = old_credential_table.insert()
+    for credential in session.query(cred_table):
+        insert.execute({'id': credential.id,
+                        'user_id': credential.user_id,
+                        'project_id': credential.project_id,
+                        'blob': credential.blob,
+                        'type': credential.type,
+                        'extra': credential.extra})
+    cred_table.drop()
+    old_credential_table.rename('credential')
+    session.commit()
+    session.close()