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(
  56             ['extlinux'],
  57             'install extlinux?',
  58             default=True)
  59         self.settings.string(['tarball'], "tar up the disk's contents in FILE",
  60                              metavar='FILE')
  61         self.settings.string(['mirror'],
  62                              'use MIRROR as package source (%default)',
  63                              metavar='URL',
  64                              default='http://cdn.debian.net/debian/')
  65         self.settings.string(['arch'], 'architecture to use (%default)',
  66                              metavar='ARCH',
  67                              default=default_arch)
  68         self.settings.string(['distribution'],
  69                              'release to use (%default)',
  70                              metavar='NAME',
  71                              default='stable')
  72         self.settings.string_list(['package'], 'install PACKAGE onto system')
  73         self.settings.string_list(['custom-package'],
  74                                   'install package in DEB file onto system '
  75                                     '(not from mirror)',
  76                                   metavar='DEB')
  77         self.settings.boolean(['no-kernel'], 'do not install a linux package')
  78         self.settings.boolean(['enable-dhcp'], 'enable DHCP on eth0')
  79         self.settings.string(['root-password'], 'set root password',
  80                              metavar='PASSWORD')
  81         self.settings.boolean(['lock-root-password'],
  82                               'lock root account so they cannot login?')
  83         self.settings.string(['customize'],
  84                              'run SCRIPT after setting up system',
  85                              metavar='SCRIPT')
  86         self.settings.string(['hostname'],
  87                              'set name to HOSTNAME (%default)',
  88                              metavar='HOSTNAME',
  89                              default='debian')
  90         self.settings.string_list(['user'],
  91                                   'create USER with PASSWORD',
  92                                   metavar='USER/PASSWORD')
  93         self.settings.boolean(['serial-console'],
  94                               'configure image to use a serial console')
  95         self.settings.string(['serial-console-command'],
  96                              'command to manage the serial console, appended '
  97                                'to /etc/inittab (%default)',
  98                              metavar='COMMAND',
  99                              default='/sbin/getty -L ttyS0 115200 vt100')
 100         self.settings.boolean(['sudo'],
 101                               'install sudo, and if user is created, add them '
 102                                 'to sudo group')
 103
 104     def process_args(self, args):
 105         if not self.settings['image'] and not self.settings['tarball']:
 106             raise cliapp.AppException('You must give disk image filename, '
 107                                       'or tarball filename')
 108         if self.settings['image'] and not self.settings['size']:
 109             raise cliapp.AppException('If disk image is specified, '
 110                                       'You must give image size.')
 111
 112         self.remove_dirs = []
 113         self.mount_points = []
 114
 115         try:
 116             rootdev = None
 117             roottype = 'ext4'
 118             bootdev = None
 119             boottype = None
 120             if self.settings['image']:
 121                 self.create_empty_image()
 122                 self.partition_image()
 123                 self.install_mbr()
 124                 (rootdev,bootdev) = self.setup_kpartx()
 125                 self.mkfs(rootdev, type=roottype)
 126                 rootdir = self.mount(rootdev)
 127                 if bootdev:
 128                     if self.settings['boottype']:
 129                         boottype = self.settings['boottype']
 130                     else:
 131                         boottype = 'ext2'
 132                     self.mkfs(bootdev, type=boottype)
 133                     bootdir = '%s/%s' % (rootdir, 'boot/')
 134                     os.mkdir(bootdir)
 135                     bootdir = self.mount(bootdev, bootdir)
 136             else:
 137                 rootdir = self.mkdtemp()
 138             self.debootstrap(rootdir)
 139             self.set_hostname(rootdir)
 140             self.create_fstab(rootdir, rootdev, roottype, bootdev, boottype)
 141             self.install_debs(rootdir)
 142             self.cleanup_apt_cache(rootdir)
 143             self.set_root_password(rootdir)
 144             self.create_users(rootdir)
 145             self.remove_udev_persistent_rules(rootdir)
 146             self.setup_networking(rootdir)
 147             self.customize(rootdir)
 148             if self.settings['image']:
 149                 if not self.settings['no-extlinux']:
 150                     self.install_extlinux(rootdev, rootdir)
 151                 self.optimize_image(rootdir)
 152
 153             if self.settings['foreign']:
 154                 os.unlink('%s/usr/bin/%s' %
 155                           (rootdir, os.path.basename(self.settings['foreign'])))
 156
 157             if self.settings['tarball']:
 158                 self.create_tarball(rootdir)
 159         except BaseException, e:
 160             self.message('EEEK! Something bad happened...')
 161             self.cleanup_system()
 162             raise
 163         else:
 164             self.cleanup_system()
 165
 166     def message(self, msg):
 167         logging.info(msg)
 168         if self.settings['verbose']:
 169             print msg
 170
 171     def runcmd(self, argv, stdin='', ignore_fail=False, **kwargs):
 172         logging.debug('runcmd: %s %s' % (argv, kwargs))
 173         p = subprocess.Popen(argv, stdin=subprocess.PIPE,
 174                              stdout=subprocess.PIPE, stderr=subprocess.PIPE,
 175                              **kwargs)
 176         out, err = p.communicate(stdin)
 177         if p.returncode != 0:
 178             msg = 'command failed: %s\n%s\n%s' % (argv, out, err)
 179             logging.error(msg)
 180             if not ignore_fail:
 181                 raise cliapp.AppException(msg)
 182         return out
 183
 184     def mkdtemp(self):
 185         dirname = tempfile.mkdtemp()
 186         self.remove_dirs.append(dirname)
 187         logging.debug('mkdir %s' % dirname)
 188         return dirname
 189
 190     def mount(self, device, path=None):
 191         if not path:
 192             mount_point = self.mkdtemp()
 193         else:
 194             mount_point = path
 195         self.message('Mounting %s on %s' % (device,mount_point))
 196         self.runcmd(['mount', device, mount_point])
 197         self.mount_points.append(mount_point)
 198         logging.debug('mounted %s on %s' % (device, mount_point))
 199         return mount_point
 200
 201     def create_empty_image(self):
 202         self.message('Creating disk image')
 203         self.runcmd(['qemu-img', 'create', '-f', 'raw',
 204                      self.settings['image'],
 205                      str(self.settings['size'])])
 206
 207     def partition_image(self):
 208         self.message('Creating partitions')
 209         self.runcmd(['parted', '-s', self.settings['image'],
 210                      'mklabel', 'msdos'])
 211         if self.settings['bootsize'] and self.settings['bootsize'] is not '0%':
 212             bootsize=str(self.settings['bootsize']/(1024*1024))
 213             self.runcmd(['parted', '-s', self.settings['image'],
 214                          'mkpart', 'primary', 'fat16', '0', bootsize])
 215         else:
 216             bootsize='0%'
 217         self.runcmd(['parted', '-s', self.settings['image'],
 218                      'mkpart', 'primary', bootsize, '100%'])
 219         self.runcmd(['parted', '-s', self.settings['image'],
 220                      'set', '1', 'boot', 'on'])
 221
 222     def install_mbr(self):
 223         self.message('Installing MBR')
 224         self.runcmd(['install-mbr', self.settings['image']])
 225
 226     def setup_kpartx(self):
 227         out = self.runcmd(['kpartx', '-avs', self.settings['image']])
 228         if self.settings['bootsize']:
 229             bootindex = 0
 230             rootindex = 1
 231             parts = 2
 232         else:
 233             rootindex = 0
 234             parts = 1
 235             boot = None
 236         devices = [line.split()[2]
 237                    for line in out.splitlines()
 238                    if line.startswith('add map ')]
 239         if len(devices) != parts:
 240             raise cliapp.AppException('Surprising number of partitions')
 241         root = '/dev/mapper/%s' % devices[rootindex]
 242         if self.settings['bootsize']:
 243             boot = '/dev/mapper/%s' % devices[bootindex]
 244         return (root,boot)
 245
 246     def mkfs(self, device, type):
 247         self.message('Creating filesystem %s' % type)
 248         self.runcmd(['mkfs', '-t', type, device])
 249
 250     def debootstrap(self, rootdir):
 251         self.message('Debootstrapping')
 252
 253         if self.settings['foreign']:
 254             necessary_packages = []
 255         else:
 256             necessary_packages = ['acpid']
 257
 258         include = self.settings['package']
 259
 260         if not self.settings['no-kernel']:
 261             if self.settings['arch'] == 'i386':
 262                 kernel_arch = '486'
 263             else:
 264                 kernel_arch = self.settings['arch']
 265             kernel_image = 'linux-image-%s' % kernel_arch
 266             include.append(kernel_image)
 267
 268         if self.settings['sudo'] and 'sudo' not in include:
 269             include.append('sudo')
 270
 271         args = ['debootstrap', '--arch=%s' % self.settings['arch']]
 272         args.append(
 273             '--include=%s' % ','.join(necessary_packages + include))
 274         if self.settings['foreign']:
 275             args.append('--foreign')
 276         if self.settings['variant']:
 277             args.append('--variant')
 278             args.append(self.settings['variant'])
 279         args += [self.settings['distribution'],
 280                  rootdir, self.settings['mirror']]
 281         self.runcmd(args)
 282         if self.settings['foreign']:
 283             # First copy the binfmt handler over
 284             shutil.copy(self.settings['foreign'], '%s/usr/bin/' % rootdir)
 285             # Next, run the package install scripts etc.
 286             self.runcmd(['chroot', rootdir,
 287                          '/debootstrap/debootstrap', '--second-stage'])
 288
 289     def set_hostname(self, rootdir):
 290         hostname = self.settings['hostname']
 291         with open(os.path.join(rootdir, 'etc', 'hostname'), 'w') as f:
 292             f.write('%s\n' % hostname)
 293
 294         etc_hosts = os.path.join(rootdir, 'etc', 'hosts')
 295         with open(etc_hosts, 'r') as f:
 296             data = f.read()
 297         with open(etc_hosts, 'w') as f:
 298             for line in data.splitlines():
 299                 if line.startswith('127.0.0.1'):
 300                     line += ' %s' % hostname
 301                 f.write('%s\n' % line)
 302
 303     def create_fstab(self, rootdir, rootdev, roottype, bootdev, boottype):
 304         def fsuuid(device):
 305             out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 306                                '-s', 'UUID', device])
 307             return out.splitlines()[0].strip()
 308
 309         if rootdev:
 310             rootdevstr = 'UUID=%s' % fsuuid(rootdev)
 311         else:
 312             rootdevstr = '/dev/sda1'
 313
 314         if bootdev:
 315             bootdevstr = 'UUID=%s' % fsuuid(bootdev)
 316         else:
 317             bootdevstr = None
 318
 319         fstab = os.path.join(rootdir, 'etc', 'fstab')
 320         with open(fstab, 'w') as f:
 321             f.write('proc /proc proc defaults 0 0\n')
 322             f.write('%s / %s errors=remount-ro 0 1\n' % (rootdevstr, roottype))
 323             if bootdevstr:
 324                 f.write('%s /boot %s errors=remount-ro 0 2\n' % (bootdevstr, boottype))
 325
 326     def install_debs(self, rootdir):
 327         if not self.settings['custom-package']:
 328             return
 329         self.message('Installing custom packages')
 330         tmp = os.path.join(rootdir, 'tmp', 'install_debs')
 331         os.mkdir(tmp)
 332         for deb in self.settings['custom-package']:
 333             shutil.copy(deb, tmp)
 334         filenames = [os.path.join('/tmp/install_debs', os.path.basename(deb))
 335                      for deb in self.settings['custom-package']]
 336         out, err, exit = \
 337             self.runcmd_unchecked(['chroot', rootdir, 'dpkg', '-i'] + filenames)
 338         logging.debug('stdout:\n%s' % out)
 339         logging.debug('stderr:\n%s' % err)
 340         out = self.runcmd(['chroot', rootdir,
 341                      'apt-get', '-f', '--no-remove', 'install'])
 342         logging.debug('stdout:\n%s' % out)
 343         shutil.rmtree(tmp)
 344
 345     def cleanup_apt_cache(self, rootdir):
 346         out = self.runcmd(['chroot', rootdir, 'apt-get', 'clean'])
 347         logging.debug('stdout:\n%s' % out)
 348
 349     def set_root_password(self, rootdir):
 350         if self.settings['root-password']:
 351             self.message('Setting root password')
 352             self.set_password(rootdir, 'root', self.settings['root-password'])
 353         elif self.settings['lock-root-password']:
 354             self.message('Locking root password')
 355             self.runcmd(['chroot', rootdir, 'passwd', '-l', 'root'])
 356         else:
 357             self.message('Give root an empty password')
 358             self.delete_password(rootdir, 'root')
 359
 360     def create_users(self, rootdir):
 361         def create_user(user):
 362             self.runcmd(['chroot', rootdir, 'adduser', '--gecos', user,
 363                          '--disabled-password', user])
 364             if self.settings['sudo']:
 365                 self.runcmd(['chroot', rootdir, 'adduser', user, 'sudo'])
 366
 367         for userpass in self.settings['user']:
 368             if '/' in userpass:
 369                 user, password = userpass.split('/', 1)
 370                 create_user(user)
 371                 self.set_password(rootdir, user, password)
 372             else:
 373                 create_user(userpass)
 374                 self.delete_password(rootdir, userpass)
 375
 376     def set_password(self, rootdir, user, password):
 377         encrypted = crypt.crypt(password, '..')
 378         self.runcmd(['chroot', rootdir, 'usermod', '-p', encrypted, user])
 379
 380     def delete_password(self, rootdir, user):
 381         self.runcmd(['chroot', rootdir, 'passwd', '-d', user])
 382
 383     def remove_udev_persistent_rules(self, rootdir):
 384         self.message('Removing udev persistent cd and net rules')
 385         for x in ['70-persistent-cd.rules', '70-persistent-net.rules']:
 386             pathname = os.path.join(rootdir, 'etc', 'udev', 'rules.d', x)
 387             if os.path.exists(pathname):
 388                 logging.debug('rm %s' % pathname)
 389                 os.remove(pathname)
 390             else:
 391                 logging.debug('not removing non-existent %s' % pathname)
 392
 393     def setup_networking(self, rootdir):
 394         self.message('Setting up networking')
 395
 396         f = open(os.path.join(rootdir, 'etc', 'network', 'interfaces'), 'w')
 397         f.write('auto lo\n')
 398         f.write('iface lo inet loopback\n')
 399
 400         if self.settings['enable-dhcp']:
 401             f.write('\n')
 402             f.write('auto eth0\n')
 403             f.write('iface eth0 inet dhcp\n')
 404
 405         f.close()
 406
 407     def install_extlinux(self, rootdev, rootdir):
 408         self.message('Installing extlinux')
 409
 410         def find(pattern):
 411             dirname = os.path.join(rootdir, 'boot')
 412             basenames = os.listdir(dirname)
 413             logging.debug('find: %s' % basenames)
 414             for basename in basenames:
 415                 if re.search(pattern, basename):
 416                     return os.path.join('boot', basename)
 417             raise cliapp.AppException('Cannot find match: %s' % pattern)
 418
 419         kernel_image = find('vmlinuz-.*')
 420         initrd_image = find('initrd.img-.*')
 421
 422         out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 423                            '-s', 'UUID', rootdev])
 424         uuid = out.splitlines()[0].strip()
 425
 426         conf = os.path.join(rootdir, 'extlinux.conf')
 427         logging.debug('configure extlinux %s' % conf)
 428         f = open(conf, 'w')
 429         f.write('''
 430 default linux
 431 timeout 1
 432
 433 label linux
 434 kernel %(kernel)s
 435 append initrd=%(initrd)s root=UUID=%(uuid)s ro %(kserial)s
 436 %(extserial)s
 437 ''' % {
 438     'kernel': kernel_image,
 439     'initrd': initrd_image,
 440     'uuid': uuid,
 441     'kserial':
 442         'console=ttyS0,115200' if self.settings['serial-console'] else '',
 443     'extserial': 'serial 0 115200' if self.settings['serial-console'] else '',
 444 })
 445         f.close()
 446
 447         if self.settings['serial-console']:
 448             serial_command = self.settings['serial-console-command']
 449             logging.debug('adding getty to serial console')
 450             inittab = os.path.join(rootdir, 'etc/inittab')
 451             with open(inittab, 'a') as f:
 452                 f.write('\nS0:23:respawn:%s\n' % serial_command)
 453
 454         self.runcmd(['extlinux', '--install', rootdir])
 455         self.runcmd(['sync'])
 456         import time; time.sleep(2)
 457
 458     def optimize_image(self, rootdir):
 459         """
 460         Filing up the image with zeros will increase its compression rate
 461         """
 462         zeros = os.path.join(rootdir, 'ZEROS')
 463         self.runcmd_unchecked(['dd', 'if=/dev/zero', 'of=' + zeros, 'bs=1M'])
 464         self.runcmd(['rm', '-f', zeros])
 465
 466
 467     def cleanup_system(self):
 468         # Clean up after any errors.
 469
 470         self.message('Cleaning up')
 471
 472         # Umount in the reverse mount order
 473         if self.settings['image']:
 474             for i in xrange(len(self.mount_points) - 1, -1, -1):
 475                 mount_point = self.mount_points[i]
 476                 try:
 477                     self.runcmd(['umount', mount_point], ignore_fail=False)
 478                 except cliapp.AppException:
 479                     logging.debug("umount failed, sleeping and trying again")
 480                     time.sleep(5)
 481                     self.runcmd(['umount', mount_point], ignore_fail=False)
 482
 483             self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True)
 484
 485         for dirname in self.remove_dirs:
 486             shutil.rmtree(dirname)
 487
 488     def customize(self, rootdir):
 489         script = self.settings['customize']
 490         if script:
 491             self.message('Running customize script %s' % script)
 492             with open('/dev/tty', 'w') as tty:
 493                 cliapp.runcmd([script, rootdir], stdout=tty, stderr=tty)
 494
 495     def create_tarball(self, rootdir):
 496         # Create a tarball of the disk's contents
 497         # shell out to runcmd since it more easily handles rootdir
 498         self.message('Creating tarball of disk contents')
 499         self.runcmd(['tar', '-cf', self.settings['tarball'], '-C', rootdir, '.'])
 500
 501
 502 if __name__ == '__main__':
 503     VmDebootstrap(version=__version__).run()
 504