Re: [libvirt] RFC: Introduce API to query IP addresses for given domain

On Fri, Jun 28, 2013 at 03:56:10PM +0530, Nehal J. Wani wrote: > Hello, fellow developers! > I am a GSoC candidate this year working for libvirt.org. My > project is "Introduce API to query IP addresses for given domain". > The discussion regarding this feature had started here: > http://www.mail-archive.com/libvir-list@redhat.com/msg51857.html and > then Michal had sent a patch too (refer: > http://www.mail-archive.com/libvir-list@redhat.com/msg57141.html). But > it was not pushed upstream due to lack of extensibility. > > So far I've come up with an API and I want to get your opinion before > I start writing the rest so I don't follow the wrong direction. > > Following are the valid commands: > > domifaddr <domain-name> > domifaddr <domain-name> <interface-name> > domifaddr <domain-name> <interface-name> <method> > domifaddr <domain-name> <method> What are valid values for '<method>' here ? > > methods: > (i) Querying qemu-guest-agent > (ii) Getting info from dnsmasq.leases file > (iii) Using the nwfilter to snoop the traffic > > If no method is mentioned, qemu-guest-agent will be used. > > Previous attempts by Michal had used structs and xml. Structs bring in > restrictions and xml has to be parsed. Hence I am not planning to > continue with either of these. > > As a start, I would like to know your comments about my API which > queries the qemu-guest-agent and returns the results in > virTypedParameter **params. > > Format(JSON) in which the qemu guest agent returns info: > > [{"name":"lo", > "ip-addresses": > [{"ip-address-type":"ipv4","ip-address":"127.0.0.1","prefix":8}, > {"ip-address-type":"ipv6","ip-address":"::1","prefix":128}], > "hardware-address":"00:00:00:00:00:00"}, > {"name":"eth0", > "ip-addresses": > [{"ip-address-type":"ipv4","ip-address":"192.168.122.42","prefix":24}, > {"ip-address-type":"ipv6","ip-address":"fe80::5054:ff:fe09:d240","prefix":64}], > "hardware-address":"52:54:00:09:d2:40"}] > > //Possible 1-D Structure (A little hassle to maintain) > > params[0] = {"iface-count",int,2} > params[1] = {"iface-name",string,"lo"} > params[2] = {"iface-hwaddr",string,"00:00:00:00:00:00"} > params[3] = {"iface-addr-count",int,2} > params[4] = {"iface-addr-type",string,"ipv4"} > params[5] = {"iface-addr",string,"127.0.0.1"} > params[6] = {"iface-addr-prefix",int,8} > params[7] = {"iface-addr-type",string,"ipv6"} > params[8] = {"iface-addr",string,"::1"} > params[9] = {"iface-addr-prefix",int,128} > .... > .... > .... > > //2D Structure: (Not very hasslefree, but easier to maintain as one > interface per row) > > params[0] = {"iface-name",string,"lo"}{"iface-hwaddr",string,"00:00:00:00:00:00"}{"iface-addr-type",string,"ipv4"}{"iface-addr",string,"127.0.0.1"}{"iface-addr-prefix",int,8}{"iface-addr-type",string,"ipv6"}{"iface-addr",string,"::1"}{"iface-addr-prefix",int,128} > params[1] = {"iface-name",string,"eth0"}{"iface-hwaddr",string,"52:54:00:09:d2:40"}{"iface-addr-type",string,"ipv4"}{"iface-addr",string,"192.168.122.42"}{"iface-addr-prefix",int,8}{"iface-addr-type",string,"ipv6"}{"iface-addr",string,"fe80::5054:ff:fe09:d240"}{"iface-addr-prefix",int,64} IMHO both of these approaches to encoding the data in virTypedParameter are seriously unpleasant for an app to deal with. Now this is a true for virTypedParameter in general, but I think that the need to deal with a list of objects here, each containing a list of typed parameters makes it even worse than normal. I wouldn't really like this as an application developer. Looking at this possible approach of virTypedParameter, I'm think I am preferring either the XML or fixed struct approach to this API as was proposed in the past, with a bias towards a fixed struct for simplicity of use by app developers. Regards, Danuiel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/:| |: http://libvirt.org -o- http://virt-manager.org:| |: http://autobuild.org -o- http://search.cpan.org/~danberr/:| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc:|