[libvirt-users] VM parameters best practice?

Hi, When creating many virtual machines from a template (disk image), you often need to set some different parameters for each vm. Those usually include root passwords and/or ssh public keys for login, ssh Host keys (so that a) not all the VMs have the same host key and b) the user can know the real host key for his vm before connecting for the first time) plus any number of user-defined parameters. IP addresses and hostnames can be set via DHCP. Obviously, some of those parameters need to be treated as confidential, so you cannot just grab them from some FTP server somewhere. In fact, as long as you haven't set any authentication credentials (like an SSL Client Certificate for example) that the vm can use to uniquely and securely identify itself to some server, you cannot securely get any of these parameters over the network. How do people usually solve that sort of problem? What is considered best practice here? Currently, my own plans are to write these parameters to a floppy image, use Unix file permissions to make sure nobody else can read the image, and then hook up that image to a virtual floppy drive in the respective vm. A shell script in the vm template can then read and apply all those parameter at some early stage during the very first boot. Unfortunately, this means mounting the image in the host system, writing the parameters and then unmounting it again - which seems sort of error prone to me in a fully automated environment. (What if two vms are being created simultaneously? What if the script crashes or hangs somewhere between mounting and unmounting the image?) Regards Guido Winkelmann