[libvirt] [RFC] The Quest for Domain-IP Mapping Continues...

[Nehal J Wani]

On Fri, Dec 5, 2014 at 3:33 PM, Daniel P. Berrange <berrange at redhat.com> wrote:
> On Fri, Dec 05, 2014 at 12:20:03AM +0530, Nehal J Wani wrote:
>> If you remember correctly, about 1.2 years ago, we had...
>> https://www.redhat.com/archives/libvir-list/2013-September/msg00351.html
>>
>> In short, the patch proposed a generalized mechanism for finding out
>> IP addresses, with flags for choosing method(s) (SNOOP|LEASE|AGENT).
>>
>> But since not all methods were supported (only qemu-ga worked), the
>> API was deferred.
>>
>> After exploring a bit, it seems that in all, we can have:
>> (i) Leases Method
>> (ii) Qemu Guest Agent
>> (iiI) DHCP Snooping (exists, but isn't publicly exposed?)
>> (iv) ARP Snooping (we can ask the virtual network interfaces to share
>> their arp tables with the public?)
>>
>> Now that we have the dhcp-leases API fully furnished, why not visit
>> the qemu-guest-agent again?
>>
>> OP1. Should we have separate APIs + virsh commands for each one of
>> these and then combine them together under
>> virDomainInterfaceAddresses?
>> - If each one has to be a different API and then combined later, then
>> what should be the corresponding name for the virsh command for
>> exposing the querying guest agent API?
>> OP2. Implement virDomainInterfaceAddresses API with two flags, one for
>> dhcp-leases and another for qemu-ga and keep adding others whenever
>> they are completed?
>
> I don't see any real reason to have separate APIs for each method.
> The API signature will be the same in all cases, so having a single
> virDomainGetInterfaceAddrs() method with a bunch of flags to control
> what data source is used is preferrable. I'd expect the DHCP leases
> method to be used as the default, since that's the most likely method
> to succeed in the common case.

So, should I go ahead and redo that patch, with two flags enabled?
Or
Should I send a patch only for qemuAgentGetInterfaces (and testcases) first?


>
> Regards,
> Daniel
> --
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-- 
Nehal J Wani