[libvirt] [PATCH] Make dnsmasq run from libvirtd reading /etc/ethers

[Daniel P. Berrange]

On Mon, Oct 05, 2009 at 06:00:47AM +0900, Satoru SATOH wrote:
> The following small patch makes dnsmasq run from libvirtd reading
> /etc/ethers and enables static ip address assignment with it.
> 
> 
> Libvirtd already supports static ip address assignment by
> //ip/dhcp/host element in network xml definition file, however the
> number of the assignments looks limited by ARG_MAX or similar parameters
> when dnsmasq is exec-ed.
> 
> This patch implements a workaround for this issue and the number of
> static ip assignments becomes only limited by dnsmasq (I'm not sure the
> exact number but it should large enough for most cases, I guess).

This is the wrong way to approach this priblem since it moves a
key configuration parameter outside the scope of the libvirt API.
The second problem is that it is a single file per host, whereas
libvirt can have multiple independant dnsmasq instances per host
each with different config. 

If the problem is that we're getting too many  --dhcp-host args
causing us to hit command line length limits, then we should 
switch to using  --dhcp-hostsfile and write out a per-dnsmasq
config file in /var/lib/libvirt/network/$NETWORKNAME.dhcpmap

Regards,
Daniel
-- 
|: Red Hat, Engineering, London   -o-   http://people.redhat.com/berrange/ :|
|: http://libvirt.org  -o-  http://virt-manager.org  -o-  http://ovirt.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505  -o-  F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|