I’d like to add a “restore” feature to xen-create-image to go alongside the “install disk”, “install lvm” etc options. It would take an existing disk, mount it and apply some “restore” scripts to it. It would skip over the “create the disk and put stuff on it” part.

The xen-create-image script (in xen-tools) is almost all the way there. It’s fairly modular. It calls other scripts to do parts of its work (like xt-create-xen-config). Those scripts get the (extensive) list of options by inheriting them in the environment.

That means xen-create-image exports the list of config options to its environment. It does this in the exportEnvironment function — except for the ip address list. That is done in runCustomisationHooks. Most unfortunte for me, because the main part of the script goes like this:

exportEnvironment();
if ( $CONFIG{'install'} ) {
    ...
    if ( $CONFIG{'hooks'} ) {
        runCustomisationHooks ();
    }
}

It’s that way in xen-tools 4.2 and in xen-tools 3.2.

Unfortunately, that means that not only are the ip variables not available if I’m not installing, but neither do the customisation hooks get run. I had been hoping to make a new “distro” called “restore” in which I could put scripts like “restore-database-from-dump” and “fix-up-networking-for-new-dom0-location” and suchlike.

I’ve subscribed to the xen-tools mailing list and submitted my comments, we’ll see what happens.