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(['mirror'],
  41                              'use MIRROR as package source (%default)',
  42                              metavar='URL',
  43                              default='http://cdn.debian.net/debian/')
  44         self.settings.string(['arch'], 'architecture to use (%default)',
  45                              metavar='ARCH',
  46                              default=default_arch)
  47         self.settings.string(['distribution'],
  48                              'release to use (%default)',
  49                              metavar='NAME',
  50                              default='stable')
  51         self.settings.string_list(['package'], 'install PACKAGE onto system')
  52         self.settings.string_list(['custom-package'],
  53                                   'install package in DEB file onto system '
  54                                     '(not from mirror)',
  55                                   metavar='DEB')
  56         self.settings.boolean(['enable-dhcp'], 'enable DHCP on eth0')
  57         self.settings.string(['root-password'], 'set root password',
  58                              metavar='PASSWORD')
  59         self.settings.boolean(['lock-root-password'],
  60                               'lock root account so they cannot login?')
  61         self.settings.string(['customize'],
  62                              'run SCRIPT after setting up system',
  63                              metavar='SCRIPT')
  64         self.settings.string(['hostname'],
  65                              'set name to HOSTNAME (%default)',
  66                              metavar='HOSTNAME',
  67                              default='debian')
  68         self.settings.string_list(['user'],
  69                                   'create USER with PASSWORD',
  70                                   metavar='USER/PASSWORD')
  71         self.settings.boolean(['serial-console'],
  72                               'configure image to use a serial console')
  73         self.settings.boolean(['sudo'],
  74                               'install sudo, and if user is created, add them '
  75                                 'to sudo group')
  76
  77     def process_args(self, args):
  78         if not self.settings['image']:
  79             raise cliapp.AppException('You must give image filename.')
  80         if not self.settings['size']:
  81             raise cliapp.AppException('You must give image size.')
  82
  83         self.remove_dirs = []
  84         self.mount_points = []
  85
  86         try:
  87             self.create_empty_image()
  88             self.partition_image()
  89             self.install_mbr()
  90             rootdev = self.setup_kpartx()
  91             self.mkfs(rootdev)
  92             rootdir = self.mount(rootdev)
  93             self.debootstrap(rootdir)
  94             self.set_hostname(rootdir)
  95             self.create_fstab(rootdir)
  96             self.install_debs(rootdir)
  97             self.set_root_password(rootdir)
  98             self.create_users(rootdir)
  99             self.remove_udev_persistent_rules(rootdir)
 100             self.setup_networking(rootdir)
 101             self.install_extlinux(rootdev, rootdir)
 102             self.customize(rootdir)
 103         except BaseException, e:
 104             self.message('EEEK! Something bad happened...')
 105             self.cleanup_system()
 106             raise
 107         else:
 108             self.cleanup_system()
 109
 110     def message(self, msg):
 111         logging.info(msg)
 112         if self.settings['verbose']:
 113             print msg
 114
 115     def runcmd(self, argv, stdin='', ignore_fail=False, **kwargs):
 116         logging.debug('runcmd: %s %s' % (argv, kwargs))
 117         p = subprocess.Popen(argv, stdin=subprocess.PIPE,
 118                              stdout=subprocess.PIPE, stderr=subprocess.PIPE,
 119                              **kwargs)
 120         out, err = p.communicate(stdin)
 121         if p.returncode != 0:
 122             msg = 'command failed: %s\n%s\n%s' % (argv, out, err)
 123             logging.error(msg)
 124             if not ignore_fail:
 125                 raise cliapp.AppException(msg)
 126         return out
 127
 128     def mkdtemp(self):
 129         dirname = tempfile.mkdtemp()
 130         self.remove_dirs.append(dirname)
 131         logging.debug('mkdir %s' % dirname)
 132         return dirname
 133
 134     def mount(self, device):
 135         self.message('Mounting %s' % device)
 136         mount_point = self.mkdtemp()
 137         self.runcmd(['mount', device, mount_point])
 138         self.mount_points.append(mount_point)
 139         logging.debug('mounted %s on %s' % (device, mount_point))
 140         return mount_point
 141
 142     def create_empty_image(self):
 143         self.message('Creating disk image')
 144         self.runcmd(['qemu-img', 'create', '-f', 'raw',
 145                      self.settings['image'],
 146                      str(self.settings['size'])])
 147
 148     def partition_image(self):
 149         self.message('Creating partitions')
 150         self.runcmd(['parted', '-s', self.settings['image'],
 151                      'mklabel', 'msdos'])
 152         self.runcmd(['parted', '-s', self.settings['image'],
 153                      'mkpart', 'primary', '0%', '100%'])
 154         self.runcmd(['parted', '-s', self.settings['image'],
 155                      'set', '1', 'boot', 'on'])
 156
 157     def install_mbr(self):
 158         self.message('Installing MBR')
 159         self.runcmd(['install-mbr', self.settings['image']])
 160
 161     def setup_kpartx(self):
 162         out = self.runcmd(['kpartx', '-av', self.settings['image']])
 163         devices = [line.split()[2]
 164                    for line in out.splitlines()
 165                    if line.startswith('add map ')]
 166         if len(devices) != 1:
 167             raise cliapp.AppException('Surprising number of partitions')
 168         return '/dev/mapper/%s' % devices[0]
 169
 170     def mkfs(self, device):
 171         self.message('Creating filesystem')
 172         self.runcmd(['mkfs', '-t', 'ext2', device])
 173
 174     def debootstrap(self, rootdir):
 175         self.message('Debootstrapping')
 176
 177         if self.settings['arch'] == 'i386':
 178             kernel_arch = '686'
 179         else:
 180             kernel_arch = self.settings['arch']
 181         kernel_image = 'linux-image-2.6-%s' % kernel_arch
 182
 183         include = [kernel_image] + self.settings['package']
 184         if self.settings['sudo'] and 'sudo' not in include:
 185             include.append('sudo')
 186
 187         self.runcmd(['debootstrap',
 188                      '--arch=%s' % self.settings['arch'],
 189                      '--include=%s' % ','.join(include),
 190                      self.settings['distribution'],
 191                      rootdir,
 192                      self.settings['mirror']])
 193
 194     def set_hostname(self, rootdir):
 195         hostname = self.settings['hostname']
 196         with open(os.path.join(rootdir, 'etc', 'hostname'), 'w') as f:
 197             f.write('%s\n' % hostname)
 198
 199         etc_hosts = os.path.join(rootdir, 'etc', 'hosts')
 200         with open(etc_hosts, 'r') as f:
 201             data = f.read()
 202         with open(etc_hosts, 'w') as f:
 203             for line in data.splitlines():
 204                 if line.startswith('127.0.0.1'):
 205                     line += ' %s' % hostname
 206                 f.write('%s\n' % line)
 207
 208     def create_fstab(self, rootdir):
 209         fstab = os.path.join(rootdir, 'etc', 'fstab')
 210         with open(fstab, 'w') as f:
 211             f.write('proc /proc proc defaults 0 0\n')
 212             f.write('/dev/sda1 / ext4 errors=remount-ro 0 1\n')
 213
 214     def install_debs(self, rootdir):
 215         if not self.settings['custom-package']:
 216             return
 217         self.message('Installing custom packages')
 218         tmp = os.path.join(rootdir, 'tmp', 'install_debs')
 219         os.mkdir(tmp)
 220         for deb in self.settings['custom-package']:
 221             shutil.copy(deb, tmp)
 222         filenames = [os.path.join('/tmp/install_debs', os.path.basename(deb))
 223                      for deb in self.settings['custom-package']]
 224         out, err, exit = \
 225             self.runcmd_unchecked(['chroot', rootdir, 'dpkg', '-i'] + filenames)
 226         logging.debug('stdout:\n%s' % out)
 227         logging.debug('stderr:\n%s' % err)
 228         out = self.runcmd(['chroot', rootdir,
 229                      'apt-get', '-f', '--no-remove', 'install'])
 230         logging.debug('stdout:\n%s' % out)
 231         shutil.rmtree(tmp)
 232
 233     def set_root_password(self, rootdir):
 234         if self.settings['root-password']:
 235             self.message('Setting root password')
 236             self.set_password(rootdir, 'root', self.settings['root-password'])
 237         elif self.settings['lock-root-password']:
 238             self.message('Locking root password')
 239             self.runcmd(['chroot', rootdir, 'passwd', '-l', 'root'])
 240         else:
 241             self.message('Give root an empty password')
 242             self.delete_password(rootdir, 'root')
 243
 244     def create_users(self, rootdir):
 245         def create_user(user):
 246             self.runcmd(['chroot', rootdir, 'adduser', '--gecos', user,
 247                          '--disabled-password', user])
 248             if self.settings['sudo']:
 249                 self.runcmd(['chroot', rootdir, 'adduser', user, 'sudo'])
 250
 251         for userpass in self.settings['user']:
 252             if '/' in userpass:
 253                 user, password = userpass.split('/', 1)
 254                 create_user(user)
 255                 self.set_password(rootdir, user, password)
 256             else:
 257                 create_user(userpass)
 258                 self.delete_password(rootdir, userpass)
 259
 260     def set_password(self, rootdir, user, password):
 261         encrypted = crypt.crypt(password, '..')
 262         self.runcmd(['chroot', rootdir, 'usermod', '-p', encrypted, user])
 263
 264     def delete_password(self, rootdir, user):
 265         self.runcmd(['chroot', rootdir, 'passwd', '-d', user])
 266
 267     def remove_udev_persistent_rules(self, rootdir):
 268         self.message('Removing udev persistent cd and net rules')
 269         for x in ['70-persistent-cd.rules', '70-persistent-net.rules']:
 270             pathname = os.path.join(rootdir, 'etc', 'udev', 'rules.d', x)
 271             if os.path.exists(pathname):
 272                 logging.debug('rm %s' % pathname)
 273                 os.remove(pathname)
 274             else:
 275                 logging.debug('not removing non-existent %s' % pathname)
 276
 277     def setup_networking(self, rootdir):
 278         self.message('Setting up networking')
 279
 280         f = open(os.path.join(rootdir, 'etc', 'network', 'interfaces'), 'w')
 281         f.write('auto lo\n')
 282         f.write('iface lo inet loopback\n')
 283
 284         if self.settings['enable-dhcp']:
 285             f.write('\n')
 286             f.write('allow-hotplug eth0\n')
 287             f.write('iface eth0 inet dhcp\n')
 288
 289         f.close()
 290
 291     def install_extlinux(self, rootdev, rootdir):
 292         self.message('Installing extlinux')
 293
 294         def find(pattern):
 295             dirname = os.path.join(rootdir, 'boot')
 296             basenames = os.listdir(dirname)
 297             logging.debug('find: %s' % basenames)
 298             for basename in basenames:
 299                 if re.search(pattern, basename):
 300                     return os.path.join('boot', basename)
 301             raise cliapp.AppException('Cannot find match: %s' % pattern)
 302
 303         kernel_image = find('vmlinuz-.*')
 304         initrd_image = find('initrd.img-.*')
 305
 306         out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 307                            '-s', 'UUID', rootdev])
 308         uuid = out.splitlines()[0].strip()
 309
 310         conf = os.path.join(rootdir, 'extlinux.conf')
 311         logging.debug('configure extlinux %s' % conf)
 312         f = open(conf, 'w')
 313         f.write('''
 314 default linux
 315 timeout 1
 316
 317 label linux
 318 kernel %(kernel)s
 319 append initrd=%(initrd)s root=UUID=%(uuid)s ro quiet %(kserial)s
 320 %(extserial)s
 321 ''' % {
 322     'kernel': kernel_image,
 323     'initrd': initrd_image,
 324     'uuid': uuid,
 325     'kserial':
 326         'console=ttyS0,115200' if self.settings['serial-console'] else '',
 327     'extserial': 'serial 0 115200' if self.settings['serial-console'] else '',
 328 })
 329         f.close()
 330
 331         if self.settings['serial-console']:
 332             logging.debug('adding getty to serial console')
 333             inittab = os.path.join(rootdir, 'etc/inittab')
 334             with open(inittab, 'a') as f:
 335                 f.write('\nS0:23:respawn:/sbin/getty -L ttyS0 115200 vt100\n')
 336
 337         self.runcmd(['extlinux', '--install', rootdir])
 338         self.runcmd(['sync'])
 339         import time; time.sleep(2)
 340
 341     def cleanup_system(self):
 342         # Clean up after any errors.
 343
 344         self.message('Cleaning up')
 345
 346         for mount_point in self.mount_points:
 347             self.runcmd(['umount', mount_point], ignore_fail=True)
 348
 349         self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True)
 350
 351         for dirname in self.remove_dirs:
 352             shutil.rmtree(dirname)
 353
 354     def customize(self, rootdir):
 355         script = self.settings['customize']
 356         if script:
 357             self.message('Running customize script %s' % script)
 358             with open('/dev/tty', 'w') as tty:
 359                 cliapp.runcmd([script, rootdir], stdout=tty, stderr=tty)
 360
 361
 362 if __name__ == '__main__':
 363     VmDebootstrap().run()
 364