Hello,

I run bird on a system which uses systemd as a service supervisor, and would like to implement graceful restart in a way which works well with it.

In particular, what I'd like to do is:

If I restart the bird service (e.g. for an upgrade), Bird performs a graceful restart
If I manually stop bird (systemctl stop bird2), shutdown the system, or any other action which is liable to cause a longer period of downtime, perform a graceful restart (for BGP at least)

Ideally systemd would have an ExecStopRestart option which could be used to distinguish between stops and restarts, but unfortunately it doesn't (I might submit a feature request for this regardless). However, it does support KillSignal and RestartKillSignal options.

So therefore I was wondering how the Bird developers and users would feel about introducing a signal (SIGUSR2 maybe?) which can be used to request that Bird perform a graceful restart?

- Erin