[libvirt] [PATCH 0/7] Introduce API for dumping domain IP addresses

[Alex Jia]

On 06/08/2012 04:04 PM, Michal Privoznik wrote:
> This feature has been requested for a very long time. However,
I'm very glad to see this patch :-)
> we had to wait for guest agent to obtain reliable results as
Yeah, it's a good way to get guest IP by GA, the disadvantage is we have 
to depend on
GA installation the guest, sometimes, it probably is a trouble thing, 
for example, I use
virt-v2v to convert a existing ESX VM into libvirt then the ESX VM 
impossible had GA
installation ago, if I want to automate to finish all of stuff, but I 
don't know VM IP address,
so I can't automatically install GA in the converted VM, it may be a 
special case for you.

However, 'tcpdump' or 'nmap' can do the same thing without GA 
installation in the guest,
maybe, we may have optional solution for how to get guest IP, of course, 
it's just my idea.
> user might create totally different structure of interfaces than
> seen from outside (e.g. bonding, virtual interfaces, etc.).
> That's the main reason why sniffing for domain traffic can
> return bogus results. Fortunately, qemu guest agent implement
> requested part for a while so nothing holds us back anymore.
>
> To make matters worse, guest OS can assign whatever name to
> an interface and changing MAC inside guest isn't propagated
> to the host which in the end see original one.
>
> Therefore, finding correlation between interface within guest
> and the host side end is left as exercise for mgmt applications.
>
> This API is called virDomainInterfacesAddresses (okay, maybe
> too many plurals) and returns a dynamically allocated array
> of virDomainInterface struct. The great disadvantage once
> this gets released, it's written in stone and we cannot change
> or add an item into it. Therefore we might add a padding into
> it - something like reserved for future use. On the other hand,
> everything important is already there - what else we will want
> to add? :)
>
> There are basically two approaches:
> 1) two APIs: one for list interfaces names, the other for querying
>     addresses on singe interface
>
> 2) one API that returns everything
>
> I've chosen the latter as it's race free (query for interface that
> has gone meanwhile).
>
> Michal Privoznik (7):
>    Introduce virDomainInterfacesAddresses API
>    virsh: Expose virDomainInterfacesAddresses
>    qemu_agent: Implement 'guest-network-get-interfaces' command handling
>    qemu: Implement virDomainInterfacesAddresses
>    remote: Implement virDomainInterfacesAddresses
>    python: Expose virDomainInterfacesAddresses
>    python: create example for dumping domain IP addresses
>
>   daemon/remote.c                 |  122 ++++++++++++++++++++++++++++++
>   examples/python/Makefile.am     |    2 +-
>   examples/python/README          |    1 +
>   examples/python/domipaddrs.py   |   50 ++++++++++++
>   include/libvirt/libvirt.h.in    |   32 ++++++++
>   python/generator.py             |    1 +
>   python/libvirt-override-api.xml |    6 ++
>   python/libvirt-override.c       |  116 ++++++++++++++++++++++++++++
>   src/driver.h                    |    6 ++
>   src/libvirt.c                   |  101 +++++++++++++++++++++++++
>   src/libvirt_public.syms         |    5 +
>   src/qemu/qemu_agent.c           |  158 +++++++++++++++++++++++++++++++++++++++
>   src/qemu/qemu_agent.h           |    4 +
>   src/qemu/qemu_driver.c          |   76 +++++++++++++++++++
>   src/remote/remote_driver.c      |   95 +++++++++++++++++++++++
>   src/remote/remote_protocol.x    |   25 ++++++-
>   tools/virsh.c                   |   92 +++++++++++++++++++++++
>   tools/virsh.pod                 |   10 +++
>   18 files changed, 900 insertions(+), 2 deletions(-)
>   create mode 100644 examples/python/domipaddrs.py
>