No way to determine whether contract migrations are pending

[Ihar Hrachyshka]

It's needed because depending on that fact operators may need to proceed with full shutdown of their API services, or may skip such high impact step in upgrade procedures.

Ansible playbooks for neutron already rely on some hacky way to determine that: https://github.com/openstack/openstack-ansible/blob/aa9230b5a5cdf0e7baf57b5fb8fc6e149912b0fa/playbooks/roles/os_neutron/library/neutron_migrations_facts#L162

We should accommodate those users that want to utilize the benefits of split branches in production with a simple CLI command.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/248190
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=eb084af29da6b8b9bb5608f294acaaa44f923895
Submitter: Jenkins
Branch: master

commit eb084af29da6b8b9bb5608f294acaaa44f923895
Author: Ihar Hrachyshka <email address hidden>
Date: Fri Nov 20 18:23:08 2015 +0100

    neutron-db-manage: add has_offline_migrations command

    This command should be used by operators and deployment tools to
    determine whether full neutron-server shutdown is needed for database
    upgrade.

    The change also makes neutron-db-manage tool to return the cumulative
    result of commands being issued (in most cases it will still be 0 only,
    since our command handlers implicitly return None).

    DocImpact: Update doc to add new command 'has_offline_migrations' to
    'neutron-db-manage' tool. The command determines whether full
    neutron-server shutdown is needed for database upgrade.

    Closes-Bug: #1519118
    Change-Id: I7c5a4882ad4f80459ebe69c9a9c43cc60ce50200
    Co-Authored-By: Martin Hickey <email address hidden>

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/276351

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/276351
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=ef5c5f08bcdb25f2514b0da55994131655752ea5
Submitter: Jenkins
Branch: master

commit ef5c5f08bcdb25f2514b0da55994131655752ea5
Author: Martin Hickey <email address hidden>
Date: Thu Feb 4 16:51:12 2016 +0000

    Correct dev documentation for has_offline_migrations command

    Update the upgrade defref doc to more correctly explain the output
    from the has_offline_migrations command

    Change-Id: Ie68c31354f664165a0c124fb151e8fb449eec8ec
    Related-Bug: #1519118

[Thierry Carrez (ttx)]

This issue was fixed in the openstack/neutron 8.0.0.0b3 development milestone.