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