vmdebootstrap

   1 #!/usr/bin/python
   2 # Copyright 2011, 2012  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
  27
  28 __version__ = '0.1.0'
  29
  30
  31 class VmDebootstrap(cliapp.Application):
  32
  33     def add_settings(self):
  34         default_arch = 'amd64'
  35
  36         self.settings.boolean(['verbose'], 'report what is going on')
  37         self.settings.string(['image'], 'put created disk image in FILE',
  38                              metavar='FILE')
  39         self.settings.bytesize(['size'],
  40                                'create a disk image of size SIZE (%default)',
  41                                metavar='SIZE',
  42                                default='1G')
  43         self.settings.bytesize(['bootsize'],
  44                                'create boot partition of size SIZE (%default)',
  45                                metavar='BOOTSIZE',
  46                                default='0%')
  47         self.settings.string(['boottype'],
  48                              'specify file system type for /boot/',
  49                              default='ext2')
  50         self.settings.string(['foreign'],
  51                              'set up foreign debootstrap environment using provided program (ie binfmt handler)')
  52         self.settings.string(['variant'],
  53                              'select debootstrap variant it not using the default')
  54         self.settings.boolean(['no-extlinux'], 'do not install extlinux')
  55         self.settings.string(['tarball'], "tar up the disk's contents in FILE",
  56                              metavar='FILE')
  57         self.settings.string(['mirror'],
  58                              'use MIRROR as package source (%default)',
  59                              metavar='URL',
  60                              default='http://cdn.debian.net/debian/')
  61         self.settings.string(['arch'], 'architecture to use (%default)',
  62                              metavar='ARCH',
  63                              default=default_arch)
  64         self.settings.string(['distribution'],
  65                              'release to use (%default)',
  66                              metavar='NAME',
  67                              default='stable')
  68         self.settings.string_list(['package'], 'install PACKAGE onto system')
  69         self.settings.string_list(['custom-package'],
  70                                   'install package in DEB file onto system '
  71                                     '(not from mirror)',
  72                                   metavar='DEB')
  73         self.settings.boolean(['no-kernel'], 'do not install a linux package')
  74         self.settings.boolean(['enable-dhcp'], 'enable DHCP on eth0')
  75         self.settings.string(['root-password'], 'set root password',
  76                              metavar='PASSWORD')
  77         self.settings.boolean(['lock-root-password'],
  78                               'lock root account so they cannot login?')
  79         self.settings.string(['customize'],
  80                              'run SCRIPT after setting up system',
  81                              metavar='SCRIPT')
  82         self.settings.string(['hostname'],
  83                              'set name to HOSTNAME (%default)',
  84                              metavar='HOSTNAME',
  85                              default='debian')
  86         self.settings.string_list(['user'],
  87                                   'create USER with PASSWORD',
  88                                   metavar='USER/PASSWORD')
  89         self.settings.boolean(['serial-console'],
  90                               'configure image to use a serial console')
  91         self.settings.string(['serial-console-command'],
  92                              'command to manage the serial console, appended '
  93                                'to /etc/inittab (%default)',
  94                              metavar='COMMAND',
  95                              default='/sbin/getty -L ttyS0 115200 vt100')
  96         self.settings.boolean(['sudo'],
  97                               'install sudo, and if user is created, add them '
  98                                 'to sudo group')
  99
 100     def process_args(self, args):
 101         if not self.settings['image'] and not self.settings['tarball']:
 102             raise cliapp.AppException('You must give disk image filename, '
 103                                       'or tarball filename')
 104         if self.settings['image'] and not self.settings['size']:
 105             raise cliapp.AppException('If disk image is specified, '
 106                                       'You must give image size.')
 107
 108         self.remove_dirs = []
 109         self.mount_points = []
 110
 111         try:
 112             if self.settings['image']:
 113                 self.create_empty_image()
 114                 self.partition_image()
 115                 self.install_mbr()
 116                 (rootdev,bootdev) = self.setup_kpartx()
 117                 self.mkfs(rootdev)
 118                 rootdir = self.mount(rootdev)
 119                 if bootdev:
 120                     if self.settings['boottype']:
 121                         fstype = self.settings['boottype']
 122                     else:
 123                         fstype = 'ext2'
 124                     self.mkfs(bootdev, type=fstype)
 125                     bootdir = '%s/%s' % (rootdir, 'boot/')
 126                     os.mkdir(bootdir)
 127                     bootdir = self.mount(bootdev, bootdir)
 128             else:
 129                 rootdir = self.mkdtemp()
 130             self.debootstrap(rootdir)
 131             self.set_hostname(rootdir)
 132             self.create_fstab(rootdir)
 133             self.install_debs(rootdir)
 134             self.cleanup_apt_cache(rootdir)
 135             self.set_root_password(rootdir)
 136             self.create_users(rootdir)
 137             self.remove_udev_persistent_rules(rootdir)
 138             self.setup_networking(rootdir)
 139             self.customize(rootdir)
 140             if self.settings['image']:
 141                 if not self.settings['no-extlinux']:
 142                     self.install_extlinux(rootdev, rootdir)
 143                 self.optimize_image(rootdir)
 144
 145             if self.settings['foreign']:
 146                 os.unlink('%s/usr/bin/%s' %
 147                           (rootdir, os.path.basename(self.settings['foreign'])))
 148
 149             if self.settings['tarball']:
 150                 self.create_tarball(rootdir)
 151         except BaseException, e:
 152             self.message('EEEK! Something bad happened...')
 153             self.cleanup_system()
 154             raise
 155         else:
 156             self.cleanup_system()
 157
 158     def message(self, msg):
 159         logging.info(msg)
 160         if self.settings['verbose']:
 161             print msg
 162
 163     def runcmd(self, argv, stdin='', ignore_fail=False, **kwargs):
 164         logging.debug('runcmd: %s %s' % (argv, kwargs))
 165         p = subprocess.Popen(argv, stdin=subprocess.PIPE,
 166                              stdout=subprocess.PIPE, stderr=subprocess.PIPE,
 167                              **kwargs)
 168         out, err = p.communicate(stdin)
 169         if p.returncode != 0:
 170             msg = 'command failed: %s\n%s\n%s' % (argv, out, err)
 171             logging.error(msg)
 172             if not ignore_fail:
 173                 raise cliapp.AppException(msg)
 174         return out
 175
 176     def mkdtemp(self):
 177         dirname = tempfile.mkdtemp()
 178         self.remove_dirs.append(dirname)
 179         logging.debug('mkdir %s' % dirname)
 180         return dirname
 181
 182     def mount(self, device, path=None):
 183         self.message('Mounting %s' % device)
 184         if not path:
 185             mount_point = self.mkdtemp()
 186         else:
 187             mount_point = path
 188         self.runcmd(['mount', device, mount_point])
 189         self.mount_points.append(mount_point)
 190         logging.debug('mounted %s on %s' % (device, mount_point))
 191         return mount_point
 192
 193     def create_empty_image(self):
 194         self.message('Creating disk image')
 195         self.runcmd(['qemu-img', 'create', '-f', 'raw',
 196                      self.settings['image'],
 197                      str(self.settings['size'])])
 198
 199     def partition_image(self):
 200         self.message('Creating partitions')
 201         self.runcmd(['parted', '-s', self.settings['image'],
 202                      'mklabel', 'msdos'])
 203         if self.settings['bootsize'] and self.settings['bootsize'] is not '0%':
 204             bootsize=str(self.settings['bootsize']/(1024*1024))
 205             self.runcmd(['parted', '-s', self.settings['image'],
 206                          'mkpart', 'primary', 'fat16', '0', bootsize])
 207         else:
 208             bootsize='0%'
 209         self.runcmd(['parted', '-s', self.settings['image'],
 210                      'mkpart', 'primary', bootsize, '100%'])
 211         self.runcmd(['parted', '-s', self.settings['image'],
 212                      'set', '1', 'boot', 'on'])
 213
 214     def install_mbr(self):
 215         self.message('Installing MBR')
 216         self.runcmd(['install-mbr', self.settings['image']])
 217
 218     def setup_kpartx(self):
 219         out = self.runcmd(['kpartx', '-av', self.settings['image']])
 220         if self.settings['bootsize']:
 221             bootindex = 0
 222             rootindex = 1
 223             parts = 2
 224         else:
 225             rootindex = 0
 226             parts = 1
 227             boot = None
 228         devices = [line.split()[2]
 229                    for line in out.splitlines()
 230                    if line.startswith('add map ')]
 231         if len(devices) != parts:
 232             raise cliapp.AppException('Surprising number of partitions')
 233         root = '/dev/mapper/%s' % devices[rootindex]
 234         if self.settings['bootsize']:
 235             boot = '/dev/mapper/%s' % devices[bootindex]
 236         return (root,boot)
 237
 238     def mkfs(self, device, type='ext2'):
 239         self.message('Creating filesystem')
 240         self.runcmd(['mkfs', '-t', type, device])
 241
 242     def debootstrap(self, rootdir):
 243         self.message('Debootstrapping')
 244
 245         if self.settings['foreign']:
 246             necessary_packages = []
 247         else:
 248             necessary_packages = ['acpid']
 249
 250         include = self.settings['package']
 251
 252         if not self.settings['no-kernel']:
 253             if self.settings['arch'] == 'i386':
 254                 kernel_arch = '486'
 255             else:
 256                 kernel_arch = self.settings['arch']
 257             kernel_image = 'linux-image-%s' % kernel_arch
 258             include.append(kernel_image)
 259
 260         if self.settings['sudo'] and 'sudo' not in include:
 261             include.append('sudo')
 262
 263         args = ['debootstrap', '--arch=%s' % self.settings['arch']]
 264         args.append(
 265             '--include=%s' % ','.join(necessary_packages + include))
 266         if self.settings['foreign']:
 267             args.append('--foreign')
 268         if self.settings['variant']:
 269             args.append('--variant')
 270             args.append(self.settings['variant'])
 271         args += [self.settings['distribution'],
 272                  rootdir, self.settings['mirror']]
 273         self.runcmd(args)
 274         if self.settings['foreign']:
 275             # First copy the binfmt handler over
 276             shutil.copy(self.settings['foreign'], '%s/usr/bin/' % rootdir)
 277             # Next, run the package install scripts etc.
 278             self.runcmd(['chroot', rootdir,
 279                          '/debootstrap/debootstrap', '--second-stage'])
 280
 281     def set_hostname(self, rootdir):
 282         hostname = self.settings['hostname']
 283         with open(os.path.join(rootdir, 'etc', 'hostname'), 'w') as f:
 284             f.write('%s\n' % hostname)
 285
 286         etc_hosts = os.path.join(rootdir, 'etc', 'hosts')
 287         with open(etc_hosts, 'r') as f:
 288             data = f.read()
 289         with open(etc_hosts, 'w') as f:
 290             for line in data.splitlines():
 291                 if line.startswith('127.0.0.1'):
 292                     line += ' %s' % hostname
 293                 f.write('%s\n' % line)
 294
 295     def create_fstab(self, rootdir):
 296         fstab = os.path.join(rootdir, 'etc', 'fstab')
 297         with open(fstab, 'w') as f:
 298             f.write('proc /proc proc defaults 0 0\n')
 299             f.write('/dev/sda1 / ext4 errors=remount-ro 0 1\n')
 300
 301     def install_debs(self, rootdir):
 302         if not self.settings['custom-package']:
 303             return
 304         self.message('Installing custom packages')
 305         tmp = os.path.join(rootdir, 'tmp', 'install_debs')
 306         os.mkdir(tmp)
 307         for deb in self.settings['custom-package']:
 308             shutil.copy(deb, tmp)
 309         filenames = [os.path.join('/tmp/install_debs', os.path.basename(deb))
 310                      for deb in self.settings['custom-package']]
 311         out, err, exit = \
 312             self.runcmd_unchecked(['chroot', rootdir, 'dpkg', '-i'] + filenames)
 313         logging.debug('stdout:\n%s' % out)
 314         logging.debug('stderr:\n%s' % err)
 315         out = self.runcmd(['chroot', rootdir,
 316                      'apt-get', '-f', '--no-remove', 'install'])
 317         logging.debug('stdout:\n%s' % out)
 318         shutil.rmtree(tmp)
 319
 320     def cleanup_apt_cache(self, rootdir):
 321         out = self.runcmd(['chroot', rootdir, 'apt-get', 'clean'])
 322         logging.debug('stdout:\n%s' % out)
 323
 324     def set_root_password(self, rootdir):
 325         if self.settings['root-password']:
 326             self.message('Setting root password')
 327             self.set_password(rootdir, 'root', self.settings['root-password'])
 328         elif self.settings['lock-root-password']:
 329             self.message('Locking root password')
 330             self.runcmd(['chroot', rootdir, 'passwd', '-l', 'root'])
 331         else:
 332             self.message('Give root an empty password')
 333             self.delete_password(rootdir, 'root')
 334
 335     def create_users(self, rootdir):
 336         def create_user(user):
 337             self.runcmd(['chroot', rootdir, 'adduser', '--gecos', user,
 338                          '--disabled-password', user])
 339             if self.settings['sudo']:
 340                 self.runcmd(['chroot', rootdir, 'adduser', user, 'sudo'])
 341
 342         for userpass in self.settings['user']:
 343             if '/' in userpass:
 344                 user, password = userpass.split('/', 1)
 345                 create_user(user)
 346                 self.set_password(rootdir, user, password)
 347             else:
 348                 create_user(userpass)
 349                 self.delete_password(rootdir, userpass)
 350
 351     def set_password(self, rootdir, user, password):
 352         encrypted = crypt.crypt(password, '..')
 353         self.runcmd(['chroot', rootdir, 'usermod', '-p', encrypted, user])
 354
 355     def delete_password(self, rootdir, user):
 356         self.runcmd(['chroot', rootdir, 'passwd', '-d', user])
 357
 358     def remove_udev_persistent_rules(self, rootdir):
 359         self.message('Removing udev persistent cd and net rules')
 360         for x in ['70-persistent-cd.rules', '70-persistent-net.rules']:
 361             pathname = os.path.join(rootdir, 'etc', 'udev', 'rules.d', x)
 362             if os.path.exists(pathname):
 363                 logging.debug('rm %s' % pathname)
 364                 os.remove(pathname)
 365             else:
 366                 logging.debug('not removing non-existent %s' % pathname)
 367
 368     def setup_networking(self, rootdir):
 369         self.message('Setting up networking')
 370
 371         f = open(os.path.join(rootdir, 'etc', 'network', 'interfaces'), 'w')
 372         f.write('auto lo\n')
 373         f.write('iface lo inet loopback\n')
 374
 375         if self.settings['enable-dhcp']:
 376             f.write('\n')
 377             f.write('auto eth0\n')
 378             f.write('iface eth0 inet dhcp\n')
 379
 380         f.close()
 381
 382     def install_extlinux(self, rootdev, rootdir):
 383         self.message('Installing extlinux')
 384
 385         def find(pattern):
 386             dirname = os.path.join(rootdir, 'boot')
 387             basenames = os.listdir(dirname)
 388             logging.debug('find: %s' % basenames)
 389             for basename in basenames:
 390                 if re.search(pattern, basename):
 391                     return os.path.join('boot', basename)
 392             raise cliapp.AppException('Cannot find match: %s' % pattern)
 393
 394         kernel_image = find('vmlinuz-.*')
 395         initrd_image = find('initrd.img-.*')
 396
 397         out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 398                            '-s', 'UUID', rootdev])
 399         uuid = out.splitlines()[0].strip()
 400
 401         conf = os.path.join(rootdir, 'extlinux.conf')
 402         logging.debug('configure extlinux %s' % conf)
 403         f = open(conf, 'w')
 404         f.write('''
 405 default linux
 406 timeout 1
 407
 408 label linux
 409 kernel %(kernel)s
 410 append initrd=%(initrd)s root=UUID=%(uuid)s ro %(kserial)s
 411 %(extserial)s
 412 ''' % {
 413     'kernel': kernel_image,
 414     'initrd': initrd_image,
 415     'uuid': uuid,
 416     'kserial':
 417         'console=ttyS0,115200' if self.settings['serial-console'] else '',
 418     'extserial': 'serial 0 115200' if self.settings['serial-console'] else '',
 419 })
 420         f.close()
 421
 422         if self.settings['serial-console']:
 423             serial_command = self.settings['serial-console-command']
 424             logging.debug('adding getty to serial console')
 425             inittab = os.path.join(rootdir, 'etc/inittab')
 426             with open(inittab, 'a') as f:
 427                 f.write('\nS0:23:respawn:%s\n' % serial_command)
 428
 429         self.runcmd(['extlinux', '--install', rootdir])
 430         self.runcmd(['sync'])
 431         import time; time.sleep(2)
 432
 433     def optimize_image(self, rootdir):
 434         """
 435         Filing up the image with zeros will increase its compression rate
 436         """
 437         zeros = os.path.join(rootdir, 'ZEROS')
 438         self.runcmd_unchecked(['dd', 'if=/dev/zero', 'of=' + zeros, 'bs=1M'])
 439         self.runcmd(['rm', '-f', zeros])
 440
 441
 442     def cleanup_system(self):
 443         # Clean up after any errors.
 444
 445         self.message('Cleaning up')
 446
 447         # Umount in the reverse mount order
 448         if self.settings['image']:
 449             for i in xrange(len(self.mount_points) - 1, -1, -1):
 450                 mount_point = self.mount_points[i]
 451                 self.runcmd(['umount', mount_point], ignore_fail=True)
 452
 453             self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True)
 454
 455         for dirname in self.remove_dirs:
 456             shutil.rmtree(dirname)
 457
 458     def customize(self, rootdir):
 459         script = self.settings['customize']
 460         if script:
 461             self.message('Running customize script %s' % script)
 462             with open('/dev/tty', 'w') as tty:
 463                 cliapp.runcmd([script, rootdir], stdout=tty, stderr=tty)
 464
 465     def create_tarball(self, rootdir):
 466         # Create a tarball of the disk's contents
 467         # shell out to runcmd since it more easily handles rootdir
 468         self.message('Creating tarball of disk contents')
 469         self.runcmd(['tar', '-cf', self.settings['tarball'], '-C', rootdir, '.'])
 470
 471
 472 if __name__ == '__main__':
 473     VmDebootstrap(version=__version__).run()
 474