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
  27
  28 __version__ = '0.2'
  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             rootdev = None
 113             roottype = 'ext4'
 114             bootdev = None
 115             boottype = None
 116             if self.settings['image']:
 117                 self.create_empty_image()
 118                 self.partition_image()
 119                 self.install_mbr()
 120                 (rootdev,bootdev) = self.setup_kpartx()
 121                 self.mkfs(rootdev, type=roottype)
 122                 rootdir = self.mount(rootdev)
 123                 if bootdev:
 124                     if self.settings['boottype']:
 125                         boottype = self.settings['boottype']
 126                     else:
 127                         boottype = 'ext2'
 128                     self.mkfs(bootdev, type=boottype)
 129                     bootdir = '%s/%s' % (rootdir, 'boot/')
 130                     os.mkdir(bootdir)
 131                     bootdir = self.mount(bootdev, bootdir)
 132             else:
 133                 rootdir = self.mkdtemp()
 134             self.debootstrap(rootdir)
 135             self.set_hostname(rootdir)
 136             self.create_fstab(rootdir, rootdev, roottype, bootdev, boottype)
 137             self.install_debs(rootdir)
 138             self.cleanup_apt_cache(rootdir)
 139             self.set_root_password(rootdir)
 140             self.create_users(rootdir)
 141             self.remove_udev_persistent_rules(rootdir)
 142             self.setup_networking(rootdir)
 143             self.customize(rootdir)
 144             if self.settings['image']:
 145                 if not self.settings['no-extlinux']:
 146                     self.install_extlinux(rootdev, rootdir)
 147                 self.optimize_image(rootdir)
 148
 149             if self.settings['foreign']:
 150                 os.unlink('%s/usr/bin/%s' %
 151                           (rootdir, os.path.basename(self.settings['foreign'])))
 152
 153             if self.settings['tarball']:
 154                 self.create_tarball(rootdir)
 155         except BaseException, e:
 156             self.message('EEEK! Something bad happened...')
 157             self.cleanup_system()
 158             raise
 159         else:
 160             self.cleanup_system()
 161
 162     def message(self, msg):
 163         logging.info(msg)
 164         if self.settings['verbose']:
 165             print msg
 166
 167     def runcmd(self, argv, stdin='', ignore_fail=False, **kwargs):
 168         logging.debug('runcmd: %s %s' % (argv, kwargs))
 169         p = subprocess.Popen(argv, stdin=subprocess.PIPE,
 170                              stdout=subprocess.PIPE, stderr=subprocess.PIPE,
 171                              **kwargs)
 172         out, err = p.communicate(stdin)
 173         if p.returncode != 0:
 174             msg = 'command failed: %s\n%s\n%s' % (argv, out, err)
 175             logging.error(msg)
 176             if not ignore_fail:
 177                 raise cliapp.AppException(msg)
 178         return out
 179
 180     def mkdtemp(self):
 181         dirname = tempfile.mkdtemp()
 182         self.remove_dirs.append(dirname)
 183         logging.debug('mkdir %s' % dirname)
 184         return dirname
 185
 186     def mount(self, device, path=None):
 187         if not path:
 188             mount_point = self.mkdtemp()
 189         else:
 190             mount_point = path
 191         self.message('Mounting %s on %s' % (device,mount_point))
 192         self.runcmd(['mount', device, mount_point])
 193         self.mount_points.append(mount_point)
 194         logging.debug('mounted %s on %s' % (device, mount_point))
 195         return mount_point
 196
 197     def create_empty_image(self):
 198         self.message('Creating disk image')
 199         self.runcmd(['qemu-img', 'create', '-f', 'raw',
 200                      self.settings['image'],
 201                      str(self.settings['size'])])
 202
 203     def partition_image(self):
 204         self.message('Creating partitions')
 205         self.runcmd(['parted', '-s', self.settings['image'],
 206                      'mklabel', 'msdos'])
 207         if self.settings['bootsize'] and self.settings['bootsize'] is not '0%':
 208             bootsize=str(self.settings['bootsize']/(1024*1024))
 209             self.runcmd(['parted', '-s', self.settings['image'],
 210                          'mkpart', 'primary', 'fat16', '0', bootsize])
 211         else:
 212             bootsize='0%'
 213         self.runcmd(['parted', '-s', self.settings['image'],
 214                      'mkpart', 'primary', bootsize, '100%'])
 215         self.runcmd(['parted', '-s', self.settings['image'],
 216                      'set', '1', 'boot', 'on'])
 217
 218     def install_mbr(self):
 219         self.message('Installing MBR')
 220         self.runcmd(['install-mbr', self.settings['image']])
 221
 222     def setup_kpartx(self):
 223         out = self.runcmd(['kpartx', '-avs', self.settings['image']])
 224         if self.settings['bootsize']:
 225             bootindex = 0
 226             rootindex = 1
 227             parts = 2
 228         else:
 229             rootindex = 0
 230             parts = 1
 231             boot = None
 232         devices = [line.split()[2]
 233                    for line in out.splitlines()
 234                    if line.startswith('add map ')]
 235         if len(devices) != parts:
 236             raise cliapp.AppException('Surprising number of partitions')
 237         root = '/dev/mapper/%s' % devices[rootindex]
 238         if self.settings['bootsize']:
 239             boot = '/dev/mapper/%s' % devices[bootindex]
 240         return (root,boot)
 241
 242     def mkfs(self, device, type):
 243         self.message('Creating filesystem %s' % type)
 244         self.runcmd(['mkfs', '-t', type, device])
 245
 246     def debootstrap(self, rootdir):
 247         self.message('Debootstrapping')
 248
 249         if self.settings['foreign']:
 250             necessary_packages = []
 251         else:
 252             necessary_packages = ['acpid']
 253
 254         include = self.settings['package']
 255
 256         if not self.settings['no-kernel']:
 257             if self.settings['arch'] == 'i386':
 258                 kernel_arch = '486'
 259             else:
 260                 kernel_arch = self.settings['arch']
 261             kernel_image = 'linux-image-%s' % kernel_arch
 262             include.append(kernel_image)
 263
 264         if self.settings['sudo'] and 'sudo' not in include:
 265             include.append('sudo')
 266
 267         args = ['debootstrap', '--arch=%s' % self.settings['arch']]
 268         args.append(
 269             '--include=%s' % ','.join(necessary_packages + include))
 270         if self.settings['foreign']:
 271             args.append('--foreign')
 272         if self.settings['variant']:
 273             args.append('--variant')
 274             args.append(self.settings['variant'])
 275         args += [self.settings['distribution'],
 276                  rootdir, self.settings['mirror']]
 277         self.runcmd(args)
 278         if self.settings['foreign']:
 279             # First copy the binfmt handler over
 280             shutil.copy(self.settings['foreign'], '%s/usr/bin/' % rootdir)
 281             # Next, run the package install scripts etc.
 282             self.runcmd(['chroot', rootdir,
 283                          '/debootstrap/debootstrap', '--second-stage'])
 284
 285     def set_hostname(self, rootdir):
 286         hostname = self.settings['hostname']
 287         with open(os.path.join(rootdir, 'etc', 'hostname'), 'w') as f:
 288             f.write('%s\n' % hostname)
 289
 290         etc_hosts = os.path.join(rootdir, 'etc', 'hosts')
 291         with open(etc_hosts, 'r') as f:
 292             data = f.read()
 293         with open(etc_hosts, 'w') as f:
 294             for line in data.splitlines():
 295                 if line.startswith('127.0.0.1'):
 296                     line += ' %s' % hostname
 297                 f.write('%s\n' % line)
 298
 299     def create_fstab(self, rootdir, rootdev, roottype, bootdev, boottype):
 300         def fsuuid(device):
 301             out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 302                                '-s', 'UUID', device])
 303             return out.splitlines()[0].strip()
 304
 305         if rootdev:
 306             rootdevstr = 'UUID=%s' % fsuuid(rootdev)
 307         else:
 308             rootdevstr = '/dev/sda1'
 309
 310         if bootdev:
 311             bootdevstr = 'UUID=%s' % fsuuid(bootdev)
 312         else:
 313             bootdevstr = None
 314
 315         fstab = os.path.join(rootdir, 'etc', 'fstab')
 316         with open(fstab, 'w') as f:
 317             f.write('proc /proc proc defaults 0 0\n')
 318             f.write('%s / %s errors=remount-ro 0 1\n' % (rootdevstr, roottype))
 319             if bootdevstr:
 320                 f.write('%s /boot %s errors=remount-ro 0 2\n' % (bootdevstr, boottype))
 321
 322     def install_debs(self, rootdir):
 323         if not self.settings['custom-package']:
 324             return
 325         self.message('Installing custom packages')
 326         tmp = os.path.join(rootdir, 'tmp', 'install_debs')
 327         os.mkdir(tmp)
 328         for deb in self.settings['custom-package']:
 329             shutil.copy(deb, tmp)
 330         filenames = [os.path.join('/tmp/install_debs', os.path.basename(deb))
 331                      for deb in self.settings['custom-package']]
 332         out, err, exit = \
 333             self.runcmd_unchecked(['chroot', rootdir, 'dpkg', '-i'] + filenames)
 334         logging.debug('stdout:\n%s' % out)
 335         logging.debug('stderr:\n%s' % err)
 336         out = self.runcmd(['chroot', rootdir,
 337                      'apt-get', '-f', '--no-remove', 'install'])
 338         logging.debug('stdout:\n%s' % out)
 339         shutil.rmtree(tmp)
 340
 341     def cleanup_apt_cache(self, rootdir):
 342         out = self.runcmd(['chroot', rootdir, 'apt-get', 'clean'])
 343         logging.debug('stdout:\n%s' % out)
 344
 345     def set_root_password(self, rootdir):
 346         if self.settings['root-password']:
 347             self.message('Setting root password')
 348             self.set_password(rootdir, 'root', self.settings['root-password'])
 349         elif self.settings['lock-root-password']:
 350             self.message('Locking root password')
 351             self.runcmd(['chroot', rootdir, 'passwd', '-l', 'root'])
 352         else:
 353             self.message('Give root an empty password')
 354             self.delete_password(rootdir, 'root')
 355
 356     def create_users(self, rootdir):
 357         def create_user(user):
 358             self.runcmd(['chroot', rootdir, 'adduser', '--gecos', user,
 359                          '--disabled-password', user])
 360             if self.settings['sudo']:
 361                 self.runcmd(['chroot', rootdir, 'adduser', user, 'sudo'])
 362
 363         for userpass in self.settings['user']:
 364             if '/' in userpass:
 365                 user, password = userpass.split('/', 1)
 366                 create_user(user)
 367                 self.set_password(rootdir, user, password)
 368             else:
 369                 create_user(userpass)
 370                 self.delete_password(rootdir, userpass)
 371
 372     def set_password(self, rootdir, user, password):
 373         encrypted = crypt.crypt(password, '..')
 374         self.runcmd(['chroot', rootdir, 'usermod', '-p', encrypted, user])
 375
 376     def delete_password(self, rootdir, user):
 377         self.runcmd(['chroot', rootdir, 'passwd', '-d', user])
 378
 379     def remove_udev_persistent_rules(self, rootdir):
 380         self.message('Removing udev persistent cd and net rules')
 381         for x in ['70-persistent-cd.rules', '70-persistent-net.rules']:
 382             pathname = os.path.join(rootdir, 'etc', 'udev', 'rules.d', x)
 383             if os.path.exists(pathname):
 384                 logging.debug('rm %s' % pathname)
 385                 os.remove(pathname)
 386             else:
 387                 logging.debug('not removing non-existent %s' % pathname)
 388
 389     def setup_networking(self, rootdir):
 390         self.message('Setting up networking')
 391
 392         f = open(os.path.join(rootdir, 'etc', 'network', 'interfaces'), 'w')
 393         f.write('auto lo\n')
 394         f.write('iface lo inet loopback\n')
 395
 396         if self.settings['enable-dhcp']:
 397             f.write('\n')
 398             f.write('auto eth0\n')
 399             f.write('iface eth0 inet dhcp\n')
 400
 401         f.close()
 402
 403     def install_extlinux(self, rootdev, rootdir):
 404         self.message('Installing extlinux')
 405
 406         def find(pattern):
 407             dirname = os.path.join(rootdir, 'boot')
 408             basenames = os.listdir(dirname)
 409             logging.debug('find: %s' % basenames)
 410             for basename in basenames:
 411                 if re.search(pattern, basename):
 412                     return os.path.join('boot', basename)
 413             raise cliapp.AppException('Cannot find match: %s' % pattern)
 414
 415         kernel_image = find('vmlinuz-.*')
 416         initrd_image = find('initrd.img-.*')
 417
 418         out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 419                            '-s', 'UUID', rootdev])
 420         uuid = out.splitlines()[0].strip()
 421
 422         conf = os.path.join(rootdir, 'extlinux.conf')
 423         logging.debug('configure extlinux %s' % conf)
 424         f = open(conf, 'w')
 425         f.write('''
 426 default linux
 427 timeout 1
 428
 429 label linux
 430 kernel %(kernel)s
 431 append initrd=%(initrd)s root=UUID=%(uuid)s ro %(kserial)s
 432 %(extserial)s
 433 ''' % {
 434     'kernel': kernel_image,
 435     'initrd': initrd_image,
 436     'uuid': uuid,
 437     'kserial':
 438         'console=ttyS0,115200' if self.settings['serial-console'] else '',
 439     'extserial': 'serial 0 115200' if self.settings['serial-console'] else '',
 440 })
 441         f.close()
 442
 443         if self.settings['serial-console']:
 444             serial_command = self.settings['serial-console-command']
 445             logging.debug('adding getty to serial console')
 446             inittab = os.path.join(rootdir, 'etc/inittab')
 447             with open(inittab, 'a') as f:
 448                 f.write('\nS0:23:respawn:%s\n' % serial_command)
 449
 450         self.runcmd(['extlinux', '--install', rootdir])
 451         self.runcmd(['sync'])
 452         import time; time.sleep(2)
 453
 454     def optimize_image(self, rootdir):
 455         """
 456         Filing up the image with zeros will increase its compression rate
 457         """
 458         zeros = os.path.join(rootdir, 'ZEROS')
 459         self.runcmd_unchecked(['dd', 'if=/dev/zero', 'of=' + zeros, 'bs=1M'])
 460         self.runcmd(['rm', '-f', zeros])
 461
 462
 463     def cleanup_system(self):
 464         # Clean up after any errors.
 465
 466         self.message('Cleaning up')
 467
 468         # Umount in the reverse mount order
 469         if self.settings['image']:
 470             for i in xrange(len(self.mount_points) - 1, -1, -1):
 471                 mount_point = self.mount_points[i]
 472                 self.runcmd(['umount', mount_point], ignore_fail=True)
 473
 474             self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True)
 475
 476         for dirname in self.remove_dirs:
 477             shutil.rmtree(dirname)
 478
 479     def customize(self, rootdir):
 480         script = self.settings['customize']
 481         if script:
 482             self.message('Running customize script %s' % script)
 483             with open('/dev/tty', 'w') as tty:
 484                 cliapp.runcmd([script, rootdir], stdout=tty, stderr=tty)
 485
 486     def create_tarball(self, rootdir):
 487         # Create a tarball of the disk's contents
 488         # shell out to runcmd since it more easily handles rootdir
 489         self.message('Creating tarball of disk contents')
 490         self.runcmd(['tar', '-cf', self.settings['tarball'], '-C', rootdir, '.'])
 491
 492
 493 if __name__ == '__main__':
 494     VmDebootstrap(version=__version__).run()
 495