vmdebootstrap

   1 #!/usr/bin/python
   2 # Copyright 2011, 2012, 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
  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                 rootdev = self.setup_kpartx()
  96                 self.mkfs(rootdev)
  97                 rootdir = self.mount(rootdev)
  98             else:
  99                 rootdir = self.mkdtemp()
 100             self.debootstrap(rootdir)
 101             self.set_hostname(rootdir)
 102             self.create_fstab(rootdir)
 103             self.install_debs(rootdir)
 104             self.set_root_password(rootdir)
 105             self.create_users(rootdir)
 106             self.remove_udev_persistent_rules(rootdir)
 107             self.setup_networking(rootdir)
 108             self.customize(rootdir)
 109             if self.settings['image']:
 110                 self.install_extlinux(rootdev, rootdir)
 111             if self.settings['tarball']:
 112                 self.create_tarball(rootdir)
 113         except BaseException, e:
 114             self.message('EEEK! Something bad happened...')
 115             self.cleanup_system()
 116             raise
 117         else:
 118             self.cleanup_system()
 119
 120     def message(self, msg):
 121         logging.info(msg)
 122         if self.settings['verbose']:
 123             print msg
 124
 125     def runcmd(self, argv, stdin='', ignore_fail=False, **kwargs):
 126         logging.debug('runcmd: %s %s' % (argv, kwargs))
 127         p = subprocess.Popen(argv, stdin=subprocess.PIPE,
 128                              stdout=subprocess.PIPE, stderr=subprocess.PIPE,
 129                              **kwargs)
 130         out, err = p.communicate(stdin)
 131         if p.returncode != 0:
 132             msg = 'command failed: %s\n%s\n%s' % (argv, out, err)
 133             logging.error(msg)
 134             if not ignore_fail:
 135                 raise cliapp.AppException(msg)
 136         return out
 137
 138     def mkdtemp(self):
 139         dirname = tempfile.mkdtemp()
 140         self.remove_dirs.append(dirname)
 141         logging.debug('mkdir %s' % dirname)
 142         return dirname
 143
 144     def mount(self, device):
 145         self.message('Mounting %s' % device)
 146         mount_point = self.mkdtemp()
 147         self.runcmd(['mount', device, mount_point])
 148         self.mount_points.append(mount_point)
 149         logging.debug('mounted %s on %s' % (device, mount_point))
 150         return mount_point
 151
 152     def create_empty_image(self):
 153         self.message('Creating disk image')
 154         self.runcmd(['qemu-img', 'create', '-f', 'raw',
 155                      self.settings['image'],
 156                      str(self.settings['size'])])
 157
 158     def partition_image(self):
 159         self.message('Creating partitions')
 160         self.runcmd(['parted', '-s', self.settings['image'],
 161                      'mklabel', 'msdos'])
 162         self.runcmd(['parted', '-s', self.settings['image'],
 163                      'mkpart', 'primary', '0%', '100%'])
 164         self.runcmd(['parted', '-s', self.settings['image'],
 165                      'set', '1', 'boot', 'on'])
 166
 167     def setup_kpartx(self):
 168         out = self.runcmd(['kpartx', '-av', self.settings['image']])
 169         devices = [line.split()[2]
 170                    for line in out.splitlines()
 171                    if line.startswith('add map ')]
 172         if len(devices) != 1:
 173             raise cliapp.AppException('Surprising number of partitions')
 174         return '/dev/mapper/%s' % devices[0]
 175
 176     def mkfs(self, device):
 177         self.message('Creating filesystem')
 178         self.runcmd(['mkfs', '-t', 'ext2', device])
 179
 180     def debootstrap(self, rootdir):
 181         self.message('Debootstrapping')
 182
 183         include = self.settings['package']
 184
 185         if not self.settings['no-kernel']:
 186             if self.settings['arch'] == 'i386':
 187                 kernel_arch = '686'
 188             else:
 189                 kernel_arch = self.settings['arch']
 190             kernel_image = 'linux-image-2.6-%s' % kernel_arch
 191             include.append(kernel_image)
 192
 193         if self.settings['sudo'] and 'sudo' not in include:
 194             include.append('sudo')
 195
 196         args = ['debootstrap', '--arch=%s' % self.settings['arch']]
 197         if include: args.append('--include=%s' % ','.join(include))
 198         args += [self.settings['distribution'],
 199                  rootdir, self.settings['mirror']]
 200         self.runcmd(args)
 201
 202     def set_hostname(self, rootdir):
 203         hostname = self.settings['hostname']
 204         with open(os.path.join(rootdir, 'etc', 'hostname'), 'w') as f:
 205             f.write('%s\n' % hostname)
 206
 207         etc_hosts = os.path.join(rootdir, 'etc', 'hosts')
 208         with open(etc_hosts, 'r') as f:
 209             data = f.read()
 210         with open(etc_hosts, 'w') as f:
 211             for line in data.splitlines():
 212                 if line.startswith('127.0.0.1'):
 213                     line += ' %s' % hostname
 214                 f.write('%s\n' % line)
 215
 216     def create_fstab(self, rootdir):
 217         fstab = os.path.join(rootdir, 'etc', 'fstab')
 218         with open(fstab, 'w') as f:
 219             f.write('proc /proc proc defaults 0 0\n')
 220             f.write('/dev/sda1 / ext4 errors=remount-ro 0 1\n')
 221
 222     def install_debs(self, rootdir):
 223         if not self.settings['custom-package']:
 224             return
 225         self.message('Installing custom packages')
 226         tmp = os.path.join(rootdir, 'tmp', 'install_debs')
 227         os.mkdir(tmp)
 228         for deb in self.settings['custom-package']:
 229             shutil.copy(deb, tmp)
 230         filenames = [os.path.join('/tmp/install_debs', os.path.basename(deb))
 231                      for deb in self.settings['custom-package']]
 232         out, err, exit = \
 233             self.runcmd_unchecked(['chroot', rootdir, 'dpkg', '-i'] + filenames)
 234         logging.debug('stdout:\n%s' % out)
 235         logging.debug('stderr:\n%s' % err)
 236         out = self.runcmd(['chroot', rootdir,
 237                      'apt-get', '-f', '--no-remove', 'install'])
 238         logging.debug('stdout:\n%s' % out)
 239         shutil.rmtree(tmp)
 240
 241     def set_root_password(self, rootdir):
 242         if self.settings['root-password']:
 243             self.message('Setting root password')
 244             self.set_password(rootdir, 'root', self.settings['root-password'])
 245         elif self.settings['lock-root-password']:
 246             self.message('Locking root password')
 247             self.runcmd(['chroot', rootdir, 'passwd', '-l', 'root'])
 248         else:
 249             self.message('Give root an empty password')
 250             self.delete_password(rootdir, 'root')
 251
 252     def create_users(self, rootdir):
 253         def create_user(user):
 254             self.runcmd(['chroot', rootdir, 'adduser', '--gecos', user,
 255                          '--disabled-password', user])
 256             if self.settings['sudo']:
 257                 self.runcmd(['chroot', rootdir, 'adduser', user, 'sudo'])
 258
 259         for userpass in self.settings['user']:
 260             if '/' in userpass:
 261                 user, password = userpass.split('/', 1)
 262                 create_user(user)
 263                 self.set_password(rootdir, user, password)
 264             else:
 265                 create_user(userpass)
 266                 self.delete_password(rootdir, userpass)
 267
 268     def set_password(self, rootdir, user, password):
 269         encrypted = crypt.crypt(password, '..')
 270         self.runcmd(['chroot', rootdir, 'usermod', '-p', encrypted, user])
 271
 272     def delete_password(self, rootdir, user):
 273         self.runcmd(['chroot', rootdir, 'passwd', '-d', user])
 274
 275     def remove_udev_persistent_rules(self, rootdir):
 276         self.message('Removing udev persistent cd and net rules')
 277         for x in ['70-persistent-cd.rules', '70-persistent-net.rules']:
 278             pathname = os.path.join(rootdir, 'etc', 'udev', 'rules.d', x)
 279             if os.path.exists(pathname):
 280                 logging.debug('rm %s' % pathname)
 281                 os.remove(pathname)
 282             else:
 283                 logging.debug('not removing non-existent %s' % pathname)
 284
 285     def setup_networking(self, rootdir):
 286         self.message('Setting up networking')
 287
 288         f = open(os.path.join(rootdir, 'etc', 'network', 'interfaces'), 'w')
 289         f.write('auto lo\n')
 290         f.write('iface lo inet loopback\n')
 291
 292         if self.settings['enable-dhcp']:
 293             f.write('\n')
 294             f.write('allow-hotplug eth0\n')
 295             f.write('iface eth0 inet dhcp\n')
 296
 297         f.close()
 298
 299     def install_extlinux(self, rootdev, rootdir):
 300         self.message('Installing extlinux')
 301
 302         def find(pattern):
 303             dirname = os.path.join(rootdir, 'boot')
 304             basenames = os.listdir(dirname)
 305             logging.debug('find: %s' % basenames)
 306             for basename in basenames:
 307                 if re.search(pattern, basename):
 308                     return os.path.join('boot', basename)
 309             raise cliapp.AppException('Cannot find match: %s' % pattern)
 310
 311         kernel_image = find('vmlinuz-.*')
 312         initrd_image = find('initrd.img-.*')
 313
 314         out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 315                            '-s', 'UUID', rootdev])
 316         uuid = out.splitlines()[0].strip()
 317
 318         conf = os.path.join(rootdir, 'extlinux.conf')
 319         logging.debug('configure extlinux %s' % conf)
 320         f = open(conf, 'w')
 321         f.write('''
 322 default linux
 323 timeout 1
 324
 325 label linux
 326 kernel %(kernel)s
 327 append initrd=%(initrd)s root=UUID=%(uuid)s ro %(kserial)s
 328 %(extserial)s
 329 ''' % {
 330     'kernel': kernel_image,
 331     'initrd': initrd_image,
 332     'uuid': uuid,
 333     'kserial':
 334         'console=ttyS0,115200' if self.settings['serial-console'] else '',
 335     'extserial': 'serial 0 115200' if self.settings['serial-console'] else '',
 336 })
 337         f.close()
 338
 339         if self.settings['serial-console']:
 340             logging.debug('adding getty to serial console')
 341             inittab = os.path.join(rootdir, 'etc/inittab')
 342             with open(inittab, 'a') as f:
 343                 f.write('\nS0:23:respawn:/sbin/getty -L ttyS0 115200 vt100\n')
 344
 345         self.runcmd(['extlinux', '--install', rootdir])
 346         self.runcmd(['sync'])
 347         import time; time.sleep(2)
 348
 349     def cleanup_system(self):
 350         # Clean up after any errors.
 351
 352         self.message('Cleaning up')
 353
 354         if self.settings['image']:
 355             for mount_point in self.mount_points:
 356                 self.runcmd(['umount', mount_point], ignore_fail=True)
 357
 358             self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True)
 359
 360         for dirname in self.remove_dirs:
 361             shutil.rmtree(dirname)
 362
 363     def customize(self, rootdir):
 364         script = self.settings['customize']
 365         if script:
 366             self.message('Running customize script %s' % script)
 367             with open('/dev/tty', 'w') as tty:
 368                 cliapp.runcmd([script, rootdir], stdout=tty, stderr=tty)
 369
 370     def create_tarball(self, rootdir):
 371         # Create a tarball of the disk's contents
 372         # shell out to runcmd since it more easily handles rootdir
 373         self.message('Creating tarball of disk contents')
 374         self.runcmd(['tar', '-cf', self.settings['tarball'], '-C', rootdir, '.'])
 375
 376
 377 if __name__ == '__main__':
 378     VmDebootstrap().run()
 379