Arista ML2 driver doesn't synchronize HA networks with EOS correctly

[Benoît Knecht]

Running Openstack Kilo and networking-arista from master (1aa15e8).

With some HA networks already created in Neutron (created automatically when adding HA routers), restarting the CVX and neutron-server lead to those networks disappearing from EOS (not listed by "show openstack networks" anymore).

The problem seems to come from _cleanup_db() in neutron/plugins/ml2/drivers/arista/mechanism_arista.py, which is called by initialize() in the same file:

def _cleanup_db(self):
    """Clean up any uncessary entries in our DB."""
    db_tenants = db_lib.get_tenants()
    for tenant in db_tenants:
        neutron_nets = self.ndb.get_all_networks_for_tenant(tenant)
        neutron_nets_id = []
        for net in neutron_nets:
            neutron_nets_id.append(net['id'])
        db_nets = db_lib.get_networks(tenant)
        for net_id in db_nets.keys():
            if net_id not in neutron_nets_id:
                db_lib.forget_network(tenant, net_id)

Since HA networks have no tenant_id, they won't be returned by self.ndb.get_all_networks_for_tenant(tenant), so they will be removed from the DB and won't be added to EOS during synchronization (checking the arista_provisioned_nets table in the neutron database shows that the HA networks are indeed missing, while they are listed by "neutron net-list").

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/225343
Committed: https://git.openstack.org/cgit/openstack/networking-arista/commit/?id=36c441dbdc02404c4049d0f3b057a169fe857235
Submitter: Jenkins
Branch: master

commit 36c441dbdc02404c4049d0f3b057a169fe857235
Author: Shashank Hegde <email address hidden>
Date: Fri Sep 18 14:42:18 2015 -0700

    Fixed HA router network cleanup

    On neutron restart, the internal network created for HA router was cleaned up
    as there was no tenant associated with that network. This patch ensures that
    networks without tenant id are handled correctly.

    Closes-Bug: 1494310

    Change-Id: I0d9db9bc8fa48ac211fee5fde6aa3e2dc8455361