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