mirror of
https://gitlab.com/libvirt/libvirt.git
synced 2025-02-03 10:25:16 +00:00
99e4b30b39
The domain XML now understands the <listen> subelement of its
<graphics> element (including when listen type='network'), and the
network driver has an internal API that will turn a network name into
an IP address, so the final logical step is to put the glue into the
qemu driver so that when it is starting up a domain, if it finds
<listen type='network' network='xyz'/> in the XML, it will call the
network driver to get an IPv4 address associated with network xyz, and
tell qemu to listen for vnc (or spice) on that address rather than the
default address (localhost).
The motivation for this is that a large installation may want the
guests' VNC servers listening on physical interfaces rather than
localhost, so that users can connect directly from the outside; this
requires sending qemu the appropriate IP address to listen on. But
this address will of course be different for each host, and if a guest
might be migrated around from one host to another, it's important that
the guest's config not have any information embedded in it that is
specific to one particular host. <listen type='network.../> can solve
this problem in the following manner:
1) on each host, define a libvirt network of the same name,
associated with the interface on that host that should be used
for listening (for example, a simple macvtap network: <forward
mode='bridge' dev='eth0'/>, or host bridge network: <forward
mode='bridge'/> <bridge name='br0'/>
2) in the <graphics> element of each guest's domain xml, tell vnc to
listen on the network name used in step 1:
<graphics type='vnc' port='5922'>
<listen type='network'network='example-net'/>
</graphics>
(all the above also applies for graphics type='spice').
LibVirt : simple API for virtualization
Libvirt is a C toolkit to interact with the virtualization capabilities
of recent versions of Linux (and other OSes). It is free software
available under the GNU Lesser General Public License. Virtualization of
the Linux Operating System means the ability to run multiple instances of
Operating Systems concurrently on a single hardware system where the basic
resources are driven by a Linux instance. The library aim at providing
long term stable C API initially for the Xen paravirtualization but
should be able to integrate other virtualization mechanisms if needed.
Daniel Veillard <veillard@redhat.com>