No configuration options to enable/disable automatic failover of l3 and dhcp agents

[Niels van Adrichem]

The neutron-api charm does not yet have the configuration options to enable/disable automatic failover of the l3 and dhcp agents in neutron.conf for respectively versions juno and kilo upwards as described in: https://docs.openstack.org/ocata/config-reference/networking/samples/neutron.conf.html.

Although dhcp agent failover is enabled by default, l3agent failover is not. According to https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/11/html/networking_guide/sec-dvr it is recommended to enable l3agent failover when using L3-HA for SNAT, hence I argue it is appropriate to be able to configure this option.

I already made and submitted a patch for review to Gerrit at https://review.openstack.org/#/c/613328/. I'll amend it with the appropriate reference to this bug.

[Dmitrii Shcherbakov (dmitriis)]

Subscribed ~field-medium.

allow_automatic_l3agent_failover in neutron.conf is needed for Centralized SNAT failover, otherwise the snat namespace does not migrate to a different l3 agent in dvr_snat mode on failure.

[Dmitrii Shcherbakov (dmitriis)]

Neutron defaults (going back to the original commits):

neutron/conf/agent/database/agentschedulers_db.py
    cfg.BoolOpt('network_auto_schedule', default=True,
                help=_('Allow auto scheduling networks to DHCP agent.')),
    cfg.BoolOpt('allow_automatic_dhcp_failover', default=True,
                help=_('Automatically remove networks from offline DHCP '
                       'agents.')),

neutron/conf/db/l3_agentschedulers_db.py
    cfg.BoolOpt('router_auto_schedule', default=True,
                help=_('Allow auto scheduling of routers to L3 agent.')),
    cfg.BoolOpt('allow_automatic_l3agent_failover', default=False,
                help=_('Automatically reschedule routers from offline L3 '
                       'agents to online L3 agents.')),

[James Page (james-page)]

https://review.openstack.org/#/c/613328/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/613328
Committed: https://git.openstack.org/cgit/openstack/charm-neutron-api/commit/?id=5f255bc9f9c8ca1f7504b894cb073d35d1f08025
Submitter: Zuul
Branch: master

commit 5f255bc9f9c8ca1f7504b894cb073d35d1f08025
Author: Niels van Adrichem <email address hidden>
Date: Thu Oct 25 13:15:28 2018 +0000

    Enable support for l3agent- and dhcp-failover

    Implements the missing configuration options and context to configure
    allow-automatic-l3agent-failover and allow-automatic-dhcp-failover
    options in neutron.conf. The options are respectively added to
    versions juno and kilo upwards as those are the Neutron versions
    since they were first supported.

    Change-Id: I7e465b7fef13f61f7b37135a86ac2f590c0c9be6
    Closes-Bug: #1799956