From: Lars Wirzenius Date: Fri, 13 May 2011 09:45:23 +0000 (+0100) Subject: Add preliminary vmdebootstrap. X-Git-Url: https://git.siccegge.de//index.cgi?a=commitdiff_plain;h=d1ab3c214eb93554b1c9581ffde9ad510c614a5a;p=forks%2Fvmdebootstrap.git Add preliminary vmdebootstrap. --- diff --git a/vmdebootstrap b/vmdebootstrap new file mode 100755 index 0000000..be3169b --- /dev/null +++ b/vmdebootstrap @@ -0,0 +1,221 @@ +#!/usr/bin/python +# Copyright 2011 Lars Wirzenius +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +import cliapp +import logging +import os +import re +import shutil +import subprocess +import tempfile + + +class VmDebootstrap(cliapp.Application): + + def add_settings(self): + default_arch = 'amd64' + + self.settings.add_boolean_setting(['verbose'], + 'report what is going on') + self.settings.add_string_setting(['image'], + 'put created disk image in FILE', + metavar='FILE') + self.settings.add_bytesize_setting(['size'], + 'create a disk image of size SIZE ' + '(%default)', + metavar='SIZE', + default='1G') + self.settings.add_string_setting(['mirror'], + 'use MIRROR as package source ' + '(%default)', + default='http://cdn.debian.net/debian/') + self.settings.add_string_setting(['arch'], + 'architecture to use ' + '(%default)', + metavar='ARCH', + default=default_arch) + self.settings.add_string_setting(['distribution'], + 'release to use (%default)', + metavar='NAME', + default='stable') + + def process_args(self, args): + if not self.settings['image']: + raise cliapp.AppException('You must give image filename.') + if not self.settings['size']: + raise cliapp.AppException('You must give image size.') + + self.remove_dirs = [] + self.mount_points = [] + + try: + self.create_empty_image() + self.partition_image() + self.install_mbr() + rootdev = self.setup_kpartx() + self.mkfs(rootdev) + rootdir = self.mount(rootdev) + self.debootstrap(rootdir) + self.set_root_password(rootdir) + self.install_extlinux(rootdev, rootdir) + except: + self.cleanup() + raise + else: + self.cleanup() + + def message(self, msg): + if self.settings['verbose']: + print msg + + def runcmd(self, argv, stdin='', ignore_fail=False, **kwargs): + logging.debug('runcmd: %s %s' % (argv, kwargs)) + p = subprocess.Popen(argv, stdin=subprocess.PIPE, + stdout=subprocess.PIPE, stderr=subprocess.PIPE, + **kwargs) + out, err = p.communicate(stdin) + if p.returncode != 0: + msg = 'command failed: %s\n%s' % (argv, err) + logging.error(msg) + if not ignore_fail: + raise cliapp.AppException(msg) + return out + + def mkdtemp(self): + dirname = tempfile.mkdtemp() + self.remove_dirs.append(dirname) + logging.debug('mkdir %s' % dirname) + return dirname + + def mount(self, device): + self.message('Mounting %s' % device) + mount_point = self.mkdtemp() + self.runcmd(['mount', device, mount_point]) + self.mount_points.append(mount_point) + logging.debug('mounted %s on %s' % (device, mount_point)) + return mount_point + + def create_empty_image(self): + self.message('Creating disk image') + self.runcmd(['qemu-img', 'create', '-f', 'raw', + self.settings['image'], + str(self.settings['size'])]) + + def partition_image(self): + self.message('Creating partitions') + self.runcmd(['parted', '-s', self.settings['image'], + 'mklabel', 'msdos']) + self.runcmd(['parted', '-s', self.settings['image'], + 'mkpart', 'primary', '0%', '100%']) + self.runcmd(['parted', '-s', self.settings['image'], + 'set', '1', 'boot', 'on']) + + def install_mbr(self): + self.message('Installing MBR') + self.runcmd(['install-mbr', self.settings['image']]) + + def setup_kpartx(self): + out = self.runcmd(['kpartx', '-av', self.settings['image']]) + devices = [line.split()[2] + for line in out.splitlines() + if line.startswith('add map ')] + if len(devices) != 1: + raise cliapp.AppException('Surprising number of partitions') + return '/dev/mapper/%s' % devices[0] + + def mkfs(self, device): + self.message('Creating filesystem') + self.runcmd(['mkfs', '-t', 'ext2', device]) + + def debootstrap(self, rootdir): + self.message('Debootstrapping') + + if self.settings['arch'] == 'i386': + kernel_arch = 'i686' + else: + kernel_arch = self.settings['arch'] + kernel_image = 'linux-image-2.6-%s' % kernel_arch + + include = [kernel_image] + + self.runcmd(['debootstrap', + '--arch=%s' % self.settings['arch'], + '--include=%s' % ','.join(include), + self.settings['distribution'], + rootdir, + self.settings['mirror']]) + + def set_root_password(self, rootdir): + self.message('Removing root password') + self.runcmd(['chroot', rootdir, 'passwd', '-d', 'root']) + + def install_extlinux(self, rootdev, rootdir): + self.message('Installing extlinux') + + def find(pattern): + dirname = os.path.join(rootdir, 'boot') + basenames = os.listdir(dirname) + logging.debug('find: %s' % basenames) + for basename in basenames: + if re.search(pattern, basename): + return os.path.join('boot', basename) + raise cliapp.AppException('Cannot find match: %s' % pattern) + + kernel_image = find('vmlinuz-.*') + initrd_image = find('initrd.img-.*') + + out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value', + '-s', 'UUID', rootdev]) + uuid = out.splitlines()[0].strip() + + conf = os.path.join(rootdir, 'extlinux.conf') + logging.debug('configure extlinux %s' % conf) + f = open(conf, 'w') + f.write(''' +default linux +timeout 1 + +label linux +kernel %(kernel)s +append initrd=%(initrd)s root=UUID=%(uuid)s ro +''' % { + 'kernel': kernel_image, + 'initrd': initrd_image, + 'uuid': uuid, +}) + f.close() + + self.runcmd(['extlinux', '--install', rootdir]) + self.runcmd(['sync']) + import time; time.sleep(2) + + def cleanup(self): + # Clean up after any errors. + + self.message('Cleaning up') + + for mount_point in self.mount_points: + self.runcmd(['umount', mount_point], ignore_fail=True) + + self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True) + + for dirname in self.remove_dirs: + shutil.rmtree(dirname) + + +if __name__ == '__main__': + VmDebootstrap().run() +