Re: [libvirt] [PATCH 0/6] NSS module for libvirt

On Mon, Feb 15, 2016 at 05:38:37PM +0100, Michal Privoznik wrote: > Are you tired of remembering IP addresses for your domains? Do > you have enough of configuring static IPs so that you can add > them to your hosts file? Then libvirt NSS module is exactly what > you need! > > NSS does a lot in a Linux host. These patches aim at translating > domain names into IP addresses. All you need to do, is install > libnss_libvirt.so.2 (e.g. via 'make install' ran from source > dir), enable the module in nsswitch.conf: > > $ grep libvirt /etc/nsswitch.conf > hosts: files dns libvirt > > and you're all set. Now you can just: > > $ ping $mydomain > $ ssh user@$mydomain > > or anything you'd like. The only limitation is that it has to be > libvirt who has assigned the domain IP address. The limitation > comes from implementation in which > '/var/lib/libvirt/dnsmasq/*.status' files are parsed when looking > up a hostname. > > What's beautiful on this feature is that it helps any users > regardless of their systemd attitude. On systemd hosts there > already exists a similar module 'mymachines' which takes its data > from machined. And libvirt does communicate with machined when > creating a domain. But unfortunately at that time we know nothing > about guest's IPs and therefore do not tell them to machined, > which in turn can't tell anything to mymachines module. To make > things worse, machined seems to be lacking an API to tell it the > addresses later on when libvirt finds out. Therefore even systemd > distros will benefit from this feature. Nice. For a similar purpose I hacked up simplec a while ago: https://github.com/agx/simplec it works by fetching domain IPs using our APIs and stores them in a file for a dnsmasq instance to read. This allows to even collect IPs from remote URIs.