On Fri, 16 Dec 2011, John Garbutt wrote: > One use case is providing metadata to an instance before that instance > starts their network stack. A bit of an edge case, but I guess one > instance of this use case is the network injection logic used for Flat > networking. > > Would injected files cover the above case? Would it still work after the > proposed changes? > > I guess it should work, assuming nova injects the files in the same way > it does for injecting network configuration, rather than relying on the > agent to write the files once the system has booted by getting data from > the metadata service. > > Maybe this is what the configuration drive could be used for (assuming > either the agent isn't responsible for correctly mounting the > configuration drive, or it can mount the disk before it has access to > any network)?
I think it is reasonable to inject static networking configuration via configuration drive. It could even be re-named "network-configuration-drive" if there is seen to be no other use for it. I'd add code to cloud-init for ubuntu configuration based on that. I've been meaning to get around to it anyway, I just haven't done it. I think it would be quite clean to do logic on boot like: * if a scan of block devices shows one labeled "netconfig" * mount that (iso9660 or vfat) filesystem, read /config file in its root filesystem. * modify /etc/network/interfaces accordingly * continue on with boot. The only issue above that there is nothing that guarantees that the config drive volume is going to be present at the instant in boot when I start looking (it may just not have shown up yet on the scsi bus or whatever). If its not there, and cloud-init goes on with life it may expose a race. I'd have to think about that more. _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp