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