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