If l3-agent was restarted by a regular action, such as config change,
package upgrade, manually service restart etc. We should not set the
HA port down during such scenarios. Unless the physical host was
rebooted, aka the VRRP processes were all terminated.
This patch adds a new RPC call during l3 agent init, it will try to
retrieve the HA router count first. And then compare the VRRP process
(keepalived) count and 'neutron-keepalived-state-change' count
with the hosting router count. If the count matches, then that
set HA port to 'DOWN' state action will not be triggered anymore.
Closes-Bug: #1798475
Change-Id: I5e2bb64df0aaab11a640a798963372c8d91a06a8
5b7d444b31