Avoid write_standby in warm restart context.
sign-off: Jing Zhang zhangjing@microsoft.com
Why I did it
In warm restart context, we should avoid mux state change.
How I did it
Check warm restart flag before applying changes to app db.
How to verify it
Ran write_standby in table missing, key missing, field missing scenarios.
Did a warm restart, app db changes were skipped. Saw this in syslog:
WARNING write_standby: Taking no action due to ongoing warmrestart.
[write_standby]: Ignore non-auto interfaces
* In the event that `write_standby.py` is used to automatically switchover interfaces when linkmgrd or bgp crashes, ignore any interfaces that are not configured to auto-switch
Signed-off-by: Lawrence Lee <lawlee@microsoft.com>