The current virt-install code for provisioning paravirtualized guests was originally written to work with Fedora / RHEL derived distros. Basically, given an NFS/HTTP/FTP install tree URL it will: 1. Fetch $INSTALL_URL/images/xen/vmlinux, save it to /var/lib/xen/images 2. Fetch $INSTALL_URL/images/xen/initrd, save it to /var/lib/xen/images 3. Boot guest pointing to these explicit kernel & ramdisk files This takes the user straight into anaconda. All very cool for Fedora / RHEL or CentOS users. Not so handy if you're trying to install paravirtualized SuSE or Debian images. Debian appears to be focused on a chroot based bootstrap approach for their guest installs - eg the install of the guest FS is done entirely from Dom0, only booting a guest once install is complete. This is not a model I want to go for in virt-install/virt-manager[1]. The good news though, is that distros in the SuSE family do support booting the regular YAST installer in a DomU, so I'm very interested in getting this working for virt-intsall. I found the following page describing the manual steps required to kick off a guest install http://www.suse.de/~kraxel/xen/suse-guest.html And have been trying to do a proof-of-concept automation of them in python. I've attached my code to this mail, but basically is goes along like this: 1. Fetch $INSTALL_URL/ls-lR.gz, save it to a temp file 2. Unzip it & scan the files looking for the latest version of the 'kernel-xen' and 'install-initrd' RPMs with matching architecture 3. Fetch $INSTALL_URL/$KERNEL_RPM saving it to a temp file 4. Fetch $INSTALL_URL/$INSTALL_INITRD_RPM saving it to a temp file 5. Use rpm2cpio & cpio to extract the /boot/vmlinuz-XXX file from the kernel RPM 6. Use rpm2cpio & cpio to extract the entire of $INSTALL_INITRD_RPM 7. Run the /usr/sbin/mkinstallinitrd script just extracted and point it to the $KERNEL_RPM file saved earlier 8. Boot guest pointing to the initrd from step 7 and kernel from step 5. So it is definitely possible to kick off paravirtualized SuSE installs, although the procss is rather long & convoluted - and the downloads take a non-trivial amount of time (20 MB for kernel RPM & 6MB for the install_initrd RPM). My main concern is that we're executing shell/perl scripts from the install_initrd RPM which we've downloaded from an arbitrary source :-( One option would be to not run the script in step 7 and install write equivalent code to build an initrd directly in the virtinst library. That would avoid the worry of running arbitrary scripts but may not be reliable long term if SuSE change the requirements for what goes in their initrds. It'd be really nice if SuSE just provided pre-built vmlinux & initrd files for installation as they already do with baremetal - but I've not found any such files on the various download sites for SuSE I've looked at. Any one have any ideas for making this process better ? Regards, Dan. [1] It requires root on Dom0 to do the chroot stuff - so guest install can in theory compromise the entire host & all guests within. Similarly you can't control resource usage & thus install will impact performance of all other guests; Finally, it has requirements for the bootstrap tools of each distro to be installed in the Dom0 -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|
#!/usr/bin/python import urlgrabber.grabber as grabber import urlgrabber.progress as progress import gzip import tempfile import os import re baseurl = "http://ftp.opensuse.org/pub/opensuse/distribution/10.2/repo/oss/"; filelist="ls-lR.gz" def _copy_temp(fileobj, prefix, scratchdir): (fd, fn) = tempfile.mkstemp(prefix="virtinst-" + prefix, dir=scratchdir) block_size = 16384 try: while 1: buff = fileobj.read(block_size) if not buff: break os.write(fd, buff) finally: os.close(fd) return fn def fetch(url, prefix): data = grabber.urlopen(url, progress_obj = progress.TextMeter()) return _copy_temp(data, prefix, "/var/tmp") install_initrd = None kernel = None kernelname = "kernel-xen" print "Fetching " + baseurl + filelist tmpfn = fetch(baseurl + filelist, "filelist") print try: filelistData = gzip.GzipFile(tmpfn, mode = "r") arch = os.uname()[4] arches = [arch] if arch == "i686": arches.append("i586") arches.append("i386") kernelname = "kernel-xenpae" dir = None while 1: data = filelistData.readline() if not data: break if dir is None: for arch in arches: wantdir = "/suse/" + arch if data == "." + wantdir + ":\n": dir = wantdir break else: if data == "\n": dir = None else: if data[:5] != "total": filename = re.split("\s+", data)[8] if filename[:14] == "install-initrd": install_initrd = dir + "/" + filename elif filename[:len(kernelname)] == kernelname: kernel = dir + "/" + filename finally: os.unlink(tmpfn) kernelfn = None mkinitrdfn = None try: print "Fetching " + baseurl + kernel kernelfn = fetch(baseurl + kernel, "kernel") print print "Fetching " + baseurl + install_initrd install_initrdfn = fetch(baseurl + install_initrd, "install-initrd") print scratchfn = tempfile.mkdtemp(prefix="virtinst-scratch", dir="/var/tmp") (initrdfd, initrdfn) = tempfile.mkstemp(prefix="virtinst-initrd", dir="/var/tmp") os.close(initrdfd) os.system("cd " + scratchfn + " && " + \ "(rpm2cpio " + install_initrdfn + " | " + \ " cpio --quiet --extract --unconditional --make-directories)") os.system("cd " + scratchfn + " && " + \ "(rpm2cpio " + kernelfn + " | " + \ " cpio --quiet --extract --unconditional --make-directories '*vmlinuz*')") os.system("/usr/bin/perl " + scratchfn + "/usr/sbin/mkinstallinitrd " + \ "--libdir=" + scratchfn + "/usr/lib/install-initrd " + \ "--kernel-rpm=" + kernelfn + " " + \ initrdfn) finally: pass #if kernelfn is not None: # os.unlink(kernelfn) #if initrdfn is not None: # os.unlink(initrdfn)
