Re: [pve-devel] [RFC cluster/manager/network 0/6] Add support for DHCP servers to SDN

["DERUMIER, Alexandre" <alexandre.derumier@groupe-cyllene.com>]

> > But it's avoid to call ipam at vm_start. (and could be used for
> > firewall to auto generate ip filtering)
> > 
> 
> Maybe setting it there could just be an interface for setting it in
> the 
> IPAM manually?
> 
yes, use should be able to define his own ip too. (maybe directly in a
ipam gui on the sdn subnet ,   or maybe on the vm nic gui (but
registering ip in ipam),  I'm really not sure ...)


> But yes, the snapshots / backup cases certainly requires some
> thought.
> 
> Another thing I was thinking about: When we create a mapping on start
> / 
> stop we will also have to consider DHCP lease time and cannot 
> immediately re-use the IP (which is actually quite likely if IPAM
> always 
> just returns the next IP in the list). We will have to take into
> account 
> the DHCP lease time in our pve IPAM implementation and reserve the IP
> accordingly.
> 
> For dnsmasq, the dhcp hookscripts might come in handy in that case so
> we 
> know the exact expiration time.
> 
> As Thomas already mentioned, time drift in VMs (e.g. after
> hibernation) 
> can also cause real issues here..
> 
> We would also need some kind of mechanism for cleaning expired
> entries 
> automatically, otherwise local pve IPAM becomes cluttered.
> 

Can't we have simply an infinite lease time,
and simply remove leases manually from dhcp + delete ip from ipam at vm
stop/delete ?




> As far as I can tell, Kea + NetBox integration already supports DHCP 
> reservations, so we should be fine on that front.
>