Increase delayed_calls_v2.auth_context

When the keystone catalog gets big, no execution can be made because the
catalog cannot fit in the `auth_context` field.

Change-Id: I100494e467f43386be17eb397fbdf0a0edd24453
Closes-Bug: 1785654
(cherry picked from commit 1f8ae7fc86)

mistral/db/sqlalchemy/migration/alembic_migrations/versions/030_increase_delayed_calls_v2_auth_context.py

@@ -0,0 +1,36 @@
+# Copyright 2018 OpenStack Foundation.
+#
+# 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.
+
+"""Increase delayed_calls_v2.auth_context column size from JsonDictType to
+JsonMediumDictType
+
+Revision ID: 030
+Revises: 029
+Create Date: 2018-08-07 08:35:57.609328
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '030'
+down_revision = '029'
+
+from alembic import op
+from mistral.db.sqlalchemy import types as st
+
+
+def upgrade():
+    # Changing column type from JsonDictType to JsonLongDictType
+    op.alter_column('delayed_calls_v2', 'auth_context',
+                    type_=st.JsonMediumDictType())

mistral/db/v2/sqlalchemy/models.py

@@ -384,7 +384,7 @@ class DelayedCall(mb.MistralModelBase):
     method_arguments = sa.Column(st.JsonDictType())
     serializers = sa.Column(st.JsonDictType())
     key = sa.Column(sa.String(250), nullable=True)
-    auth_context = sa.Column(st.JsonDictType())
+    auth_context = sa.Column(st.JsonMediumDictType())
     execution_time = sa.Column(sa.DateTime, nullable=False)
     processing = sa.Column(sa.Boolean, default=False, nullable=False)