namespace not supported when using postgresql

[Artem Lapin]

New unique constraint for postgresql is being created (name + namespace + project_id) in 022_namespace_support.py migration, but an old one for (name + project_id) is not deleted. For this reason, creating and using workflow with different namespaces is not possible.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/675361
Committed: https://git.openstack.org/cgit/openstack/mistral/commit/?id=c3434b48eccf070c44f56b92218b1b8c3bfa6310
Submitter: Zuul
Branch: master

commit c3434b48eccf070c44f56b92218b1b8c3bfa6310
Author: Artem Lapin <email address hidden>
Date: Thu Aug 8 17:42:12 2019 +0300

    New alembic migration to support namespaces in postgresql

    We are now using drop_index to delete old constraint (name + project_id)
    in namespace support migration. It works only for MySQL, for PostgreSQL
    we should use drop_constraint to delete old constraint.
    drop_index does not affect PostgreSQL and drop_constraint does not affect
    MySQL, so we should use both for namespace support for both databases.
    Added old constraint (name + project_id) deletion for
    PostgreSQL with new migration.

    Change-Id: I137162dd2b643b24f02799c6a13e3b0c0a8d3fb5
    Closes-bug: #1838635

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/mistral 10.0.0.0b1 development milestone.