vmdebootstrap

   1 #!/usr/bin/python
   2 # Copyright 2011-2013  Lars Wirzenius
   3 # Copyright 2012  Codethink Limited
   4 #
   5 # This program is free software: you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation, either version 3 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 import cliapp
  19 import crypt
  20 import logging
  21 import os
  22 import re
  23 import shutil
  24 import subprocess
  25 import tempfile
  26 import time
  27
  28
  29 __version__ = '0.2'
  30
  31
  32 class VmDebootstrap(cliapp.Application):
  33
  34     def add_settings(self):
  35         default_arch = 'amd64'
  36
  37         self.settings.boolean(['verbose'], 'report what is going on')
  38         self.settings.string(['image'], 'put created disk image in FILE',
  39                              metavar='FILE')
  40         self.settings.bytesize(['size'],
  41                                'create a disk image of size SIZE (%default)',
  42                                metavar='SIZE',
  43                                default='1G')
  44         self.settings.bytesize(['bootsize'],
  45                                'create boot partition of size SIZE (%default)',
  46                                metavar='BOOTSIZE',
  47                                default='0%')
  48         self.settings.string(['boottype'],
  49                              'specify file system type for /boot/',
  50                              default='ext2')
  51         self.settings.string(['foreign'],
  52                              'set up foreign debootstrap environment using provided program (ie binfmt handler)')
  53         self.settings.string(['variant'],
  54                              'select debootstrap variant it not using the default')
  55         self.settings.boolean(['no-extlinux'], 'do not install extlinux')
  56         self.settings.string(['tarball'], "tar up the disk's contents in FILE",
  57                              metavar='FILE')
  58         self.settings.string(['mirror'],
  59                              'use MIRROR as package source (%default)',
  60                              metavar='URL',
  61                              default='http://cdn.debian.net/debian/')
  62         self.settings.string(['arch'], 'architecture to use (%default)',
  63                              metavar='ARCH',
  64                              default=default_arch)
  65         self.settings.string(['distribution'],
  66                              'release to use (%default)',
  67                              metavar='NAME',
  68                              default='stable')
  69         self.settings.string_list(['package'], 'install PACKAGE onto system')
  70         self.settings.string_list(['custom-package'],
  71                                   'install package in DEB file onto system '
  72                                     '(not from mirror)',
  73                                   metavar='DEB')
  74         self.settings.boolean(['no-kernel'], 'do not install a linux package')
  75         self.settings.boolean(['enable-dhcp'], 'enable DHCP on eth0')
  76         self.settings.string(['root-password'], 'set root password',
  77                              metavar='PASSWORD')
  78         self.settings.boolean(['lock-root-password'],
  79                               'lock root account so they cannot login?')
  80         self.settings.string(['customize'],
  81                              'run SCRIPT after setting up system',
  82                              metavar='SCRIPT')
  83         self.settings.string(['hostname'],
  84                              'set name to HOSTNAME (%default)',
  85                              metavar='HOSTNAME',
  86                              default='debian')
  87         self.settings.string_list(['user'],
  88                                   'create USER with PASSWORD',
  89                                   metavar='USER/PASSWORD')
  90         self.settings.boolean(['serial-console'],
  91                               'configure image to use a serial console')
  92         self.settings.string(['serial-console-command'],
  93                              'command to manage the serial console, appended '
  94                                'to /etc/inittab (%default)',
  95                              metavar='COMMAND',
  96                              default='/sbin/getty -L ttyS0 115200 vt100')
  97         self.settings.boolean(['sudo'],
  98                               'install sudo, and if user is created, add them '
  99                                 'to sudo group')
 100
 101     def process_args(self, args):
 102         if not self.settings['image'] and not self.settings['tarball']:
 103             raise cliapp.AppException('You must give disk image filename, '
 104                                       'or tarball filename')
 105         if self.settings['image'] and not self.settings['size']:
 106             raise cliapp.AppException('If disk image is specified, '
 107                                       'You must give image size.')
 108
 109         self.remove_dirs = []
 110         self.mount_points = []
 111
 112         try:
 113             rootdev = None
 114             roottype = 'ext4'
 115             bootdev = None
 116             boottype = None
 117             if self.settings['image']:
 118                 self.create_empty_image()
 119                 self.partition_image()
 120                 self.install_mbr()
 121                 (rootdev,bootdev) = self.setup_kpartx()
 122                 self.mkfs(rootdev, type=roottype)
 123                 rootdir = self.mount(rootdev)
 124                 if bootdev:
 125                     if self.settings['boottype']:
 126                         boottype = self.settings['boottype']
 127                     else:
 128                         boottype = 'ext2'
 129                     self.mkfs(bootdev, type=boottype)
 130                     bootdir = '%s/%s' % (rootdir, 'boot/')
 131                     os.mkdir(bootdir)
 132                     bootdir = self.mount(bootdev, bootdir)
 133             else:
 134                 rootdir = self.mkdtemp()
 135             self.debootstrap(rootdir)
 136             self.set_hostname(rootdir)
 137             self.create_fstab(rootdir, rootdev, roottype, bootdev, boottype)
 138             self.install_debs(rootdir)
 139             self.cleanup_apt_cache(rootdir)
 140             self.set_root_password(rootdir)
 141             self.create_users(rootdir)
 142             self.remove_udev_persistent_rules(rootdir)
 143             self.setup_networking(rootdir)
 144             self.customize(rootdir)
 145             if self.settings['image']:
 146                 if not self.settings['no-extlinux']:
 147                     self.install_extlinux(rootdev, rootdir)
 148                 self.optimize_image(rootdir)
 149
 150             if self.settings['foreign']:
 151                 os.unlink('%s/usr/bin/%s' %
 152                           (rootdir, os.path.basename(self.settings['foreign'])))
 153
 154             if self.settings['tarball']:
 155                 self.create_tarball(rootdir)
 156         except BaseException, e:
 157             self.message('EEEK! Something bad happened...')
 158             self.cleanup_system()
 159             raise
 160         else:
 161             self.cleanup_system()
 162
 163     def message(self, msg):
 164         logging.info(msg)
 165         if self.settings['verbose']:
 166             print msg
 167
 168     def runcmd(self, argv, stdin='', ignore_fail=False, **kwargs):
 169         logging.debug('runcmd: %s %s' % (argv, kwargs))
 170         p = subprocess.Popen(argv, stdin=subprocess.PIPE,
 171                              stdout=subprocess.PIPE, stderr=subprocess.PIPE,
 172                              **kwargs)
 173         out, err = p.communicate(stdin)
 174         if p.returncode != 0:
 175             msg = 'command failed: %s\n%s\n%s' % (argv, out, err)
 176             logging.error(msg)
 177             if not ignore_fail:
 178                 raise cliapp.AppException(msg)
 179         return out
 180
 181     def mkdtemp(self):
 182         dirname = tempfile.mkdtemp()
 183         self.remove_dirs.append(dirname)
 184         logging.debug('mkdir %s' % dirname)
 185         return dirname
 186
 187     def mount(self, device, path=None):
 188         if not path:
 189             mount_point = self.mkdtemp()
 190         else:
 191             mount_point = path
 192         self.message('Mounting %s on %s' % (device,mount_point))
 193         self.runcmd(['mount', device, mount_point])
 194         self.mount_points.append(mount_point)
 195         logging.debug('mounted %s on %s' % (device, mount_point))
 196         return mount_point
 197
 198     def create_empty_image(self):
 199         self.message('Creating disk image')
 200         self.runcmd(['qemu-img', 'create', '-f', 'raw',
 201                      self.settings['image'],
 202                      str(self.settings['size'])])
 203
 204     def partition_image(self):
 205         self.message('Creating partitions')
 206         self.runcmd(['parted', '-s', self.settings['image'],
 207                      'mklabel', 'msdos'])
 208         if self.settings['bootsize'] and self.settings['bootsize'] is not '0%':
 209             bootsize=str(self.settings['bootsize']/(1024*1024))
 210             self.runcmd(['parted', '-s', self.settings['image'],
 211                          'mkpart', 'primary', 'fat16', '0', bootsize])
 212         else:
 213             bootsize='0%'
 214         self.runcmd(['parted', '-s', self.settings['image'],
 215                      'mkpart', 'primary', bootsize, '100%'])
 216         self.runcmd(['parted', '-s', self.settings['image'],
 217                      'set', '1', 'boot', 'on'])
 218
 219     def install_mbr(self):
 220         self.message('Installing MBR')
 221         self.runcmd(['install-mbr', self.settings['image']])
 222
 223     def setup_kpartx(self):
 224         out = self.runcmd(['kpartx', '-avs', self.settings['image']])
 225         if self.settings['bootsize']:
 226             bootindex = 0
 227             rootindex = 1
 228             parts = 2
 229         else:
 230             rootindex = 0
 231             parts = 1
 232             boot = None
 233         devices = [line.split()[2]
 234                    for line in out.splitlines()
 235                    if line.startswith('add map ')]
 236         if len(devices) != parts:
 237             raise cliapp.AppException('Surprising number of partitions')
 238         root = '/dev/mapper/%s' % devices[rootindex]
 239         if self.settings['bootsize']:
 240             boot = '/dev/mapper/%s' % devices[bootindex]
 241         return (root,boot)
 242
 243     def mkfs(self, device, type):
 244         self.message('Creating filesystem %s' % type)
 245         self.runcmd(['mkfs', '-t', type, device])
 246
 247     def debootstrap(self, rootdir):
 248         self.message('Debootstrapping')
 249
 250         if self.settings['foreign']:
 251             necessary_packages = []
 252         else:
 253             necessary_packages = ['acpid']
 254
 255         include = self.settings['package']
 256
 257         if not self.settings['no-kernel']:
 258             if self.settings['arch'] == 'i386':
 259                 kernel_arch = '486'
 260             else:
 261                 kernel_arch = self.settings['arch']
 262             kernel_image = 'linux-image-%s' % kernel_arch
 263             include.append(kernel_image)
 264
 265         if self.settings['sudo'] and 'sudo' not in include:
 266             include.append('sudo')
 267
 268         args = ['debootstrap', '--arch=%s' % self.settings['arch']]
 269         args.append(
 270             '--include=%s' % ','.join(necessary_packages + include))
 271         if self.settings['foreign']:
 272             args.append('--foreign')
 273         if self.settings['variant']:
 274             args.append('--variant')
 275             args.append(self.settings['variant'])
 276         args += [self.settings['distribution'],
 277                  rootdir, self.settings['mirror']]
 278         self.runcmd(args)
 279         if self.settings['foreign']:
 280             # First copy the binfmt handler over
 281             shutil.copy(self.settings['foreign'], '%s/usr/bin/' % rootdir)
 282             # Next, run the package install scripts etc.
 283             self.runcmd(['chroot', rootdir,
 284                          '/debootstrap/debootstrap', '--second-stage'])
 285
 286     def set_hostname(self, rootdir):
 287         hostname = self.settings['hostname']
 288         with open(os.path.join(rootdir, 'etc', 'hostname'), 'w') as f:
 289             f.write('%s\n' % hostname)
 290
 291         etc_hosts = os.path.join(rootdir, 'etc', 'hosts')
 292         with open(etc_hosts, 'r') as f:
 293             data = f.read()
 294         with open(etc_hosts, 'w') as f:
 295             for line in data.splitlines():
 296                 if line.startswith('127.0.0.1'):
 297                     line += ' %s' % hostname
 298                 f.write('%s\n' % line)
 299
 300     def create_fstab(self, rootdir, rootdev, roottype, bootdev, boottype):
 301         def fsuuid(device):
 302             out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 303                                '-s', 'UUID', device])
 304             return out.splitlines()[0].strip()
 305
 306         if rootdev:
 307             rootdevstr = 'UUID=%s' % fsuuid(rootdev)
 308         else:
 309             rootdevstr = '/dev/sda1'
 310
 311         if bootdev:
 312             bootdevstr = 'UUID=%s' % fsuuid(bootdev)
 313         else:
 314             bootdevstr = None
 315
 316         fstab = os.path.join(rootdir, 'etc', 'fstab')
 317         with open(fstab, 'w') as f:
 318             f.write('proc /proc proc defaults 0 0\n')
 319             f.write('%s / %s errors=remount-ro 0 1\n' % (rootdevstr, roottype))
 320             if bootdevstr:
 321                 f.write('%s /boot %s errors=remount-ro 0 2\n' % (bootdevstr, boottype))
 322
 323     def install_debs(self, rootdir):
 324         if not self.settings['custom-package']:
 325             return
 326         self.message('Installing custom packages')
 327         tmp = os.path.join(rootdir, 'tmp', 'install_debs')
 328         os.mkdir(tmp)
 329         for deb in self.settings['custom-package']:
 330             shutil.copy(deb, tmp)
 331         filenames = [os.path.join('/tmp/install_debs', os.path.basename(deb))
 332                      for deb in self.settings['custom-package']]
 333         out, err, exit = \
 334             self.runcmd_unchecked(['chroot', rootdir, 'dpkg', '-i'] + filenames)
 335         logging.debug('stdout:\n%s' % out)
 336         logging.debug('stderr:\n%s' % err)
 337         out = self.runcmd(['chroot', rootdir,
 338                      'apt-get', '-f', '--no-remove', 'install'])
 339         logging.debug('stdout:\n%s' % out)
 340         shutil.rmtree(tmp)
 341
 342     def cleanup_apt_cache(self, rootdir):
 343         out = self.runcmd(['chroot', rootdir, 'apt-get', 'clean'])
 344         logging.debug('stdout:\n%s' % out)
 345
 346     def set_root_password(self, rootdir):
 347         if self.settings['root-password']:
 348             self.message('Setting root password')
 349             self.set_password(rootdir, 'root', self.settings['root-password'])
 350         elif self.settings['lock-root-password']:
 351             self.message('Locking root password')
 352             self.runcmd(['chroot', rootdir, 'passwd', '-l', 'root'])
 353         else:
 354             self.message('Give root an empty password')
 355             self.delete_password(rootdir, 'root')
 356
 357     def create_users(self, rootdir):
 358         def create_user(user):
 359             self.runcmd(['chroot', rootdir, 'adduser', '--gecos', user,
 360                          '--disabled-password', user])
 361             if self.settings['sudo']:
 362                 self.runcmd(['chroot', rootdir, 'adduser', user, 'sudo'])
 363
 364         for userpass in self.settings['user']:
 365             if '/' in userpass:
 366                 user, password = userpass.split('/', 1)
 367                 create_user(user)
 368                 self.set_password(rootdir, user, password)
 369             else:
 370                 create_user(userpass)
 371                 self.delete_password(rootdir, userpass)
 372
 373     def set_password(self, rootdir, user, password):
 374         encrypted = crypt.crypt(password, '..')
 375         self.runcmd(['chroot', rootdir, 'usermod', '-p', encrypted, user])
 376
 377     def delete_password(self, rootdir, user):
 378         self.runcmd(['chroot', rootdir, 'passwd', '-d', user])
 379
 380     def remove_udev_persistent_rules(self, rootdir):
 381         self.message('Removing udev persistent cd and net rules')
 382         for x in ['70-persistent-cd.rules', '70-persistent-net.rules']:
 383             pathname = os.path.join(rootdir, 'etc', 'udev', 'rules.d', x)
 384             if os.path.exists(pathname):
 385                 logging.debug('rm %s' % pathname)
 386                 os.remove(pathname)
 387             else:
 388                 logging.debug('not removing non-existent %s' % pathname)
 389
 390     def setup_networking(self, rootdir):
 391         self.message('Setting up networking')
 392
 393         f = open(os.path.join(rootdir, 'etc', 'network', 'interfaces'), 'w')
 394         f.write('auto lo\n')
 395         f.write('iface lo inet loopback\n')
 396
 397         if self.settings['enable-dhcp']:
 398             f.write('\n')
 399             f.write('auto eth0\n')
 400             f.write('iface eth0 inet dhcp\n')
 401
 402         f.close()
 403
 404     def install_extlinux(self, rootdev, rootdir):
 405         self.message('Installing extlinux')
 406
 407         def find(pattern):
 408             dirname = os.path.join(rootdir, 'boot')
 409             basenames = os.listdir(dirname)
 410             logging.debug('find: %s' % basenames)
 411             for basename in basenames:
 412                 if re.search(pattern, basename):
 413                     return os.path.join('boot', basename)
 414             raise cliapp.AppException('Cannot find match: %s' % pattern)
 415
 416         kernel_image = find('vmlinuz-.*')
 417         initrd_image = find('initrd.img-.*')
 418
 419         out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 420                            '-s', 'UUID', rootdev])
 421         uuid = out.splitlines()[0].strip()
 422
 423         conf = os.path.join(rootdir, 'extlinux.conf')
 424         logging.debug('configure extlinux %s' % conf)
 425         f = open(conf, 'w')
 426         f.write('''
 427 default linux
 428 timeout 1
 429
 430 label linux
 431 kernel %(kernel)s
 432 append initrd=%(initrd)s root=UUID=%(uuid)s ro %(kserial)s
 433 %(extserial)s
 434 ''' % {
 435     'kernel': kernel_image,
 436     'initrd': initrd_image,
 437     'uuid': uuid,
 438     'kserial':
 439         'console=ttyS0,115200' if self.settings['serial-console'] else '',
 440     'extserial': 'serial 0 115200' if self.settings['serial-console'] else '',
 441 })
 442         f.close()
 443
 444         if self.settings['serial-console']:
 445             serial_command = self.settings['serial-console-command']
 446             logging.debug('adding getty to serial console')
 447             inittab = os.path.join(rootdir, 'etc/inittab')
 448             with open(inittab, 'a') as f:
 449                 f.write('\nS0:23:respawn:%s\n' % serial_command)
 450
 451         self.runcmd(['extlinux', '--install', rootdir])
 452         self.runcmd(['sync'])
 453         import time; time.sleep(2)
 454
 455     def optimize_image(self, rootdir):
 456         """
 457         Filing up the image with zeros will increase its compression rate
 458         """
 459         zeros = os.path.join(rootdir, 'ZEROS')
 460         self.runcmd_unchecked(['dd', 'if=/dev/zero', 'of=' + zeros, 'bs=1M'])
 461         self.runcmd(['rm', '-f', zeros])
 462
 463
 464     def cleanup_system(self):
 465         # Clean up after any errors.
 466
 467         self.message('Cleaning up')
 468
 469         # Umount in the reverse mount order
 470         if self.settings['image']:
 471             for i in xrange(len(self.mount_points) - 1, -1, -1):
 472                 mount_point = self.mount_points[i]
 473                 try:
 474                     self.runcmd(['umount', mount_point], ignore_fail=False)
 475                 except cliapp.AppException:
 476                     logging.debug("umount failed, sleeping and trying again")
 477                     time.sleep(5)
 478                     self.runcmd(['umount', mount_point], ignore_fail=False)
 479
 480             self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True)
 481
 482         for dirname in self.remove_dirs:
 483             shutil.rmtree(dirname)
 484
 485     def customize(self, rootdir):
 486         script = self.settings['customize']
 487         if script:
 488             self.message('Running customize script %s' % script)
 489             with open('/dev/tty', 'w') as tty:
 490                 cliapp.runcmd([script, rootdir], stdout=tty, stderr=tty)
 491
 492     def create_tarball(self, rootdir):
 493         # Create a tarball of the disk's contents
 494         # shell out to runcmd since it more easily handles rootdir
 495         self.message('Creating tarball of disk contents')
 496         self.runcmd(['tar', '-cf', self.settings['tarball'], '-C', rootdir, '.'])
 497
 498
 499 if __name__ == '__main__':
 500     VmDebootstrap(version=__version__).run()
 501