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