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__ = '0.3'
  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         self.settings.string(['owner'],
 104                              'the user who will own the image when the build '
 105                                'is complete.')
 106
 107     def process_args(self, args):
 108         if not self.settings['image'] and not self.settings['tarball']:
 109             raise cliapp.AppException('You must give disk image filename, '
 110                                       'or tarball filename')
 111         if self.settings['image'] and not self.settings['size']:
 112             raise cliapp.AppException('If disk image is specified, '
 113                                       'You must give image size.')
 114
 115         self.remove_dirs = []
 116         self.mount_points = []
 117
 118         try:
 119             rootdev = None
 120             roottype = 'ext4'
 121             bootdev = None
 122             boottype = None
 123             if self.settings['image']:
 124                 self.create_empty_image()
 125                 self.partition_image()
 126                 self.install_mbr()
 127                 (rootdev,bootdev) = self.setup_kpartx()
 128                 self.mkfs(rootdev, type=roottype)
 129                 rootdir = self.mount(rootdev)
 130                 if bootdev:
 131                     if self.settings['boottype']:
 132                         boottype = self.settings['boottype']
 133                     else:
 134                         boottype = 'ext2'
 135                     self.mkfs(bootdev, type=boottype)
 136                     bootdir = '%s/%s' % (rootdir, 'boot/')
 137                     os.mkdir(bootdir)
 138                     bootdir = self.mount(bootdev, bootdir)
 139             else:
 140                 rootdir = self.mkdtemp()
 141             self.debootstrap(rootdir)
 142             self.set_hostname(rootdir)
 143             self.create_fstab(rootdir, rootdev, roottype, bootdev, boottype)
 144             self.install_debs(rootdir)
 145             self.cleanup_apt_cache(rootdir)
 146             self.set_root_password(rootdir)
 147             self.create_users(rootdir)
 148             self.remove_udev_persistent_rules(rootdir)
 149             self.setup_networking(rootdir)
 150             self.customize(rootdir)
 151             if self.settings['image']:
 152                 if self.settings['extlinux']:
 153                     self.install_extlinux(rootdev, rootdir)
 154                 self.optimize_image(rootdir)
 155
 156             if self.settings['foreign']:
 157                 os.unlink('%s/usr/bin/%s' %
 158                           (rootdir, os.path.basename(self.settings['foreign'])))
 159
 160             if self.settings['tarball']:
 161                 self.create_tarball(rootdir)
 162
 163             if self.settings['owner']:
 164                 self.chown(rootdir)
 165         except BaseException, e:
 166             self.message('EEEK! Something bad happened...')
 167             self.message(e)
 168             self.cleanup_system()
 169             raise
 170         else:
 171             self.cleanup_system()
 172
 173     def message(self, msg):
 174         logging.info(msg)
 175         if self.settings['verbose']:
 176             print msg
 177
 178     def runcmd(self, argv, stdin='', ignore_fail=False, **kwargs):
 179         logging.debug('runcmd: %s %s' % (argv, kwargs))
 180         p = subprocess.Popen(argv, stdin=subprocess.PIPE,
 181                              stdout=subprocess.PIPE, stderr=subprocess.PIPE,
 182                              **kwargs)
 183         out, err = p.communicate(stdin)
 184         if p.returncode != 0:
 185             msg = 'command failed: %s\n%s\n%s' % (argv, out, err)
 186             logging.error(msg)
 187             if not ignore_fail:
 188                 raise cliapp.AppException(msg)
 189         return out
 190
 191     def mkdtemp(self):
 192         dirname = tempfile.mkdtemp()
 193         self.remove_dirs.append(dirname)
 194         logging.debug('mkdir %s' % dirname)
 195         return dirname
 196
 197     def mount(self, device, path=None):
 198         if not path:
 199             mount_point = self.mkdtemp()
 200         else:
 201             mount_point = path
 202         self.message('Mounting %s on %s' % (device,mount_point))
 203         self.runcmd(['mount', device, mount_point])
 204         self.mount_points.append(mount_point)
 205         logging.debug('mounted %s on %s' % (device, mount_point))
 206         return mount_point
 207
 208     def create_empty_image(self):
 209         self.message('Creating disk image')
 210         self.runcmd(['qemu-img', 'create', '-f', 'raw',
 211                      self.settings['image'],
 212                      str(self.settings['size'])])
 213
 214     def partition_image(self):
 215         self.message('Creating partitions')
 216         self.runcmd(['parted', '-s', self.settings['image'],
 217                      'mklabel', 'msdos'])
 218         if self.settings['bootsize'] and self.settings['bootsize'] is not '0%':
 219             bootsize=str(self.settings['bootsize']/(1024*1024))
 220             self.runcmd(['parted', '-s', self.settings['image'],
 221                          'mkpart', 'primary', 'fat16', '0', bootsize])
 222         else:
 223             bootsize='0%'
 224         self.runcmd(['parted', '-s', self.settings['image'],
 225                      'mkpart', 'primary', bootsize, '100%'])
 226         self.runcmd(['parted', '-s', self.settings['image'],
 227                      'set', '1', 'boot', 'on'])
 228
 229     def install_mbr(self):
 230         self.message('Installing MBR')
 231         self.runcmd(['install-mbr', self.settings['image']])
 232
 233     def setup_kpartx(self):
 234         out = self.runcmd(['kpartx', '-avs', self.settings['image']])
 235         if self.settings['bootsize']:
 236             bootindex = 0
 237             rootindex = 1
 238             parts = 2
 239         else:
 240             rootindex = 0
 241             parts = 1
 242             boot = None
 243         devices = [line.split()[2]
 244                    for line in out.splitlines()
 245                    if line.startswith('add map ')]
 246         if len(devices) != parts:
 247             raise cliapp.AppException('Surprising number of partitions')
 248         root = '/dev/mapper/%s' % devices[rootindex]
 249         if self.settings['bootsize']:
 250             boot = '/dev/mapper/%s' % devices[bootindex]
 251         return (root,boot)
 252
 253     def mkfs(self, device, type):
 254         self.message('Creating filesystem %s' % type)
 255         self.runcmd(['mkfs', '-t', type, device])
 256
 257     def debootstrap(self, rootdir):
 258         self.message('Debootstrapping')
 259
 260         if self.settings['foreign']:
 261             necessary_packages = []
 262         else:
 263             necessary_packages = ['acpid']
 264
 265         include = self.settings['package']
 266
 267         if not self.settings['no-kernel']:
 268             if self.settings['arch'] == 'i386':
 269                 kernel_arch = '486'
 270             else:
 271                 kernel_arch = self.settings['arch']
 272             kernel_image = 'linux-image-%s' % kernel_arch
 273             include.append(kernel_image)
 274
 275         if self.settings['sudo'] and 'sudo' not in include:
 276             include.append('sudo')
 277
 278         args = ['debootstrap', '--arch=%s' % self.settings['arch']]
 279         args.append(
 280             '--include=%s' % ','.join(necessary_packages + include))
 281         if self.settings['foreign']:
 282             args.append('--foreign')
 283         if self.settings['variant']:
 284             args.append('--variant')
 285             args.append(self.settings['variant'])
 286         args += [self.settings['distribution'],
 287                  rootdir, self.settings['mirror']]
 288         self.runcmd(args)
 289         if self.settings['foreign']:
 290             # First copy the binfmt handler over
 291             shutil.copy(self.settings['foreign'], '%s/usr/bin/' % rootdir)
 292             # Next, run the package install scripts etc.
 293             self.runcmd(['chroot', rootdir,
 294                          '/debootstrap/debootstrap', '--second-stage'])
 295
 296     def set_hostname(self, rootdir):
 297         hostname = self.settings['hostname']
 298         with open(os.path.join(rootdir, 'etc', 'hostname'), 'w') as f:
 299             f.write('%s\n' % hostname)
 300
 301         etc_hosts = os.path.join(rootdir, 'etc', 'hosts')
 302         try:
 303             with open(etc_hosts, 'r') as f:
 304                 data = f.read()
 305             with open(etc_hosts, 'w') as f:
 306                 for line in data.splitlines():
 307                     if line.startswith('127.0.0.1'):
 308                         line += ' %s' % hostname
 309                     f.write('%s\n' % line)
 310         except IOError, e:
 311             pass
 312
 313     def create_fstab(self, rootdir, rootdev, roottype, bootdev, boottype):
 314         def fsuuid(device):
 315             out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 316                                '-s', 'UUID', device])
 317             return out.splitlines()[0].strip()
 318
 319         if rootdev:
 320             rootdevstr = 'UUID=%s' % fsuuid(rootdev)
 321         else:
 322             rootdevstr = '/dev/sda1'
 323
 324         if bootdev:
 325             bootdevstr = 'UUID=%s' % fsuuid(bootdev)
 326         else:
 327             bootdevstr = None
 328
 329         fstab = os.path.join(rootdir, 'etc', 'fstab')
 330         with open(fstab, 'w') as f:
 331             f.write('proc /proc proc defaults 0 0\n')
 332             f.write('%s / %s errors=remount-ro 0 1\n' % (rootdevstr, roottype))
 333             if bootdevstr:
 334                 f.write('%s /boot %s errors=remount-ro 0 2\n' % (bootdevstr, boottype))
 335
 336     def install_debs(self, rootdir):
 337         if not self.settings['custom-package']:
 338             return
 339         self.message('Installing custom packages')
 340         tmp = os.path.join(rootdir, 'tmp', 'install_debs')
 341         os.mkdir(tmp)
 342         for deb in self.settings['custom-package']:
 343             shutil.copy(deb, tmp)
 344         filenames = [os.path.join('/tmp/install_debs', os.path.basename(deb))
 345                      for deb in self.settings['custom-package']]
 346         out, err, exit = \
 347             self.runcmd_unchecked(['chroot', rootdir, 'dpkg', '-i'] + filenames)
 348         logging.debug('stdout:\n%s' % out)
 349         logging.debug('stderr:\n%s' % err)
 350         out = self.runcmd(['chroot', rootdir,
 351                      'apt-get', '-f', '--no-remove', 'install'])
 352         logging.debug('stdout:\n%s' % out)
 353         shutil.rmtree(tmp)
 354
 355     def cleanup_apt_cache(self, rootdir):
 356         out = self.runcmd(['chroot', rootdir, 'apt-get', 'clean'])
 357         logging.debug('stdout:\n%s' % out)
 358
 359     def set_root_password(self, rootdir):
 360         if self.settings['root-password']:
 361             self.message('Setting root password')
 362             self.set_password(rootdir, 'root', self.settings['root-password'])
 363         elif self.settings['lock-root-password']:
 364             self.message('Locking root password')
 365             self.runcmd(['chroot', rootdir, 'passwd', '-l', 'root'])
 366         else:
 367             self.message('Give root an empty password')
 368             self.delete_password(rootdir, 'root')
 369
 370     def create_users(self, rootdir):
 371         def create_user(user):
 372             self.runcmd(['chroot', rootdir, 'adduser', '--gecos', user,
 373                          '--disabled-password', user])
 374             if self.settings['sudo']:
 375                 self.runcmd(['chroot', rootdir, 'adduser', user, 'sudo'])
 376
 377         for userpass in self.settings['user']:
 378             if '/' in userpass:
 379                 user, password = userpass.split('/', 1)
 380                 create_user(user)
 381                 self.set_password(rootdir, user, password)
 382             else:
 383                 create_user(userpass)
 384                 self.delete_password(rootdir, userpass)
 385
 386     def set_password(self, rootdir, user, password):
 387         encrypted = crypt.crypt(password, '..')
 388         self.runcmd(['chroot', rootdir, 'usermod', '-p', encrypted, user])
 389
 390     def delete_password(self, rootdir, user):
 391         self.runcmd(['chroot', rootdir, 'passwd', '-d', user])
 392
 393     def remove_udev_persistent_rules(self, rootdir):
 394         self.message('Removing udev persistent cd and net rules')
 395         for x in ['70-persistent-cd.rules', '70-persistent-net.rules']:
 396             pathname = os.path.join(rootdir, 'etc', 'udev', 'rules.d', x)
 397             if os.path.exists(pathname):
 398                 logging.debug('rm %s' % pathname)
 399                 os.remove(pathname)
 400             else:
 401                 logging.debug('not removing non-existent %s' % pathname)
 402
 403     def setup_networking(self, rootdir):
 404         self.message('Setting up networking')
 405
 406         f = open(os.path.join(rootdir, 'etc', 'network', 'interfaces'), 'w')
 407         f.write('auto lo\n')
 408         f.write('iface lo inet loopback\n')
 409
 410         if self.settings['enable-dhcp']:
 411             f.write('\n')
 412             f.write('auto eth0\n')
 413             f.write('iface eth0 inet dhcp\n')
 414
 415         f.close()
 416
 417     def install_extlinux(self, rootdev, rootdir):
 418         self.message('Installing extlinux')
 419
 420         def find(pattern):
 421             dirname = os.path.join(rootdir, 'boot')
 422             basenames = os.listdir(dirname)
 423             logging.debug('find: %s' % basenames)
 424             for basename in basenames:
 425                 if re.search(pattern, basename):
 426                     return os.path.join('boot', basename)
 427             raise cliapp.AppException('Cannot find match: %s' % pattern)
 428
 429         kernel_image = find('vmlinuz-.*')
 430         initrd_image = find('initrd.img-.*')
 431
 432         out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 433                            '-s', 'UUID', rootdev])
 434         uuid = out.splitlines()[0].strip()
 435
 436         conf = os.path.join(rootdir, 'extlinux.conf')
 437         logging.debug('configure extlinux %s' % conf)
 438         f = open(conf, 'w')
 439         f.write('''
 440 default linux
 441 timeout 1
 442
 443 label linux
 444 kernel %(kernel)s
 445 append initrd=%(initrd)s root=UUID=%(uuid)s ro %(kserial)s
 446 %(extserial)s
 447 ''' % {
 448     'kernel': kernel_image,
 449     'initrd': initrd_image,
 450     'uuid': uuid,
 451     'kserial':
 452         'console=ttyS0,115200' if self.settings['serial-console'] else '',
 453     'extserial': 'serial 0 115200' if self.settings['serial-console'] else '',
 454 })
 455         f.close()
 456
 457         if self.settings['serial-console']:
 458             serial_command = self.settings['serial-console-command']
 459             logging.debug('adding getty to serial console')
 460             inittab = os.path.join(rootdir, 'etc/inittab')
 461             with open(inittab, 'a') as f:
 462                 f.write('\nS0:23:respawn:%s\n' % serial_command)
 463
 464         self.runcmd(['extlinux', '--install', rootdir])
 465         self.runcmd(['sync'])
 466         import time; time.sleep(2)
 467
 468     def optimize_image(self, rootdir):
 469         """
 470         Filing up the image with zeros will increase its compression rate
 471         """
 472         zeros = os.path.join(rootdir, 'ZEROS')
 473         self.runcmd_unchecked(['dd', 'if=/dev/zero', 'of=' + zeros, 'bs=1M'])
 474         self.runcmd(['rm', '-f', zeros])
 475
 476
 477     def cleanup_system(self):
 478         # Clean up after any errors.
 479
 480         self.message('Cleaning up')
 481
 482         # Umount in the reverse mount order
 483         if self.settings['image']:
 484             for i in xrange(len(self.mount_points) - 1, -1, -1):
 485                 mount_point = self.mount_points[i]
 486                 try:
 487                     self.runcmd(['umount', mount_point], ignore_fail=False)
 488                 except cliapp.AppException:
 489                     logging.debug("umount failed, sleeping and trying again")
 490                     time.sleep(5)
 491                     self.runcmd(['umount', mount_point], ignore_fail=False)
 492
 493             self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True)
 494
 495         for dirname in self.remove_dirs:
 496             shutil.rmtree(dirname)
 497
 498     def customize(self, rootdir):
 499         script = self.settings['customize']
 500         if script:
 501             self.message('Running customize script %s' % script)
 502             with open('/dev/tty', 'w') as tty:
 503                 cliapp.runcmd([script, rootdir], stdout=tty, stderr=tty)
 504
 505     def create_tarball(self, rootdir):
 506         # Create a tarball of the disk's contents
 507         # shell out to runcmd since it more easily handles rootdir
 508         self.message('Creating tarball of disk contents')
 509         self.runcmd(['tar', '-cf', self.settings['tarball'], '-C', rootdir, '.'])
 510
 511     def chown(self, rootdir):
 512         # Change image owner after completed build
 513         self.message("Changing owner to %s" % self.settings["owner"])
 514         subprocess.call(["chown",
 515                          self.settings["owner"],
 516                          self.settings["image"]])
 517
 518
 519 if __name__ == '__main__':
 520     VmDebootstrap(version=__version__).run()
 521