Re: [libvirt] [PATCH] leaseshelper: add enhancements to support all events
> cmd = virCommandNew(dnsmasqCapsGetBinaryPath(caps));
> virCommandAddArgFormat(cmd, "--conf-file=%s", configfile);
> - virCommandAddArgFormat(cmd, "--dhcp-script=%s", leaseshelper_path);
> + virCommandAddArgFormat(cmd, "--dhcp-script=%s",
pseudo_leaseshelper_path);
> + virCommandAddArgFormat(cmd, "--leasefile-ro");
Does dnsmasq pass through the rest of the environment we pass to it at
this point? The leaseshelper extracts quite a lot of stuff from the
environment variables that are passed by dnsmasq. In case it does we
could use an env variable to pass the interface name instead of linking
the helper and using different names.
If I use the following line of code in the function
networkBuildDhcpDaemonCommandLine ...
setenv("VIR_BRIDGE_NAME", network->def->bridge, 1);
.. then yes, the helper program invoked by dnsmasq does get to see
this variable. (It does so in Fedora20). (Looks like I acted in haste,
should've waited for more replies on RFC, sigh)
So, in the next version that I will send, should I first make a
wrapper by the name virSetEnvBlockSUID for setenv, just like we have
virGetEnvBlockSUID for getenv?
A second issue that comes into my mind is compatibility with already
existing files. Does this work when you already have a lease file? (I
didn't try it, I'm just asking).
If we use the --leasefile-ro option, then although this method will
work, but no, the lease file will *not* be read/written at all. So
even if an old one exists, its of no use.
But then again, the use of --leasefile-ro is mandatory, so that all
events are captured by our helper program. For example, renew of a
lease.
Regards,
Nehal J Wani