Hi,
I'm very surprised SO_BINDTODEVICE is still not supported on nginx.
Nowadays the SO_BINDTODEVICE is not dedicated to DHCP and this feature is absolutely not deprecated because very useful to specify specific routes on an interface and force a service to use them instead of the default of system, it acts as a filter on kernel side the socket will only see routes of the specified device, this is a huge difference compared to a bind on a source IP.
On openssh the feature is implemented using the "rdomain" statement (meaning route domain!).
I've altready identified softwares that handle BINDTODEVICE: haproxy, openssh, net-snmp, sntmptrap command tool, collectd (network plugin)
This particularly useful to limit some monitoring or admin services to a specific interfaces as we can do on a network appliance. They will use a different gateway than the default system one for instance.
So I really think this merge proposal should be re-considered.
Regards,
Emeric