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(['no-kernel'], 'do not install a linux package')
  57         self.settings.boolean(['enable-dhcp'], 'enable DHCP on eth0')
  58         self.settings.string(['root-password'], 'set root password',
  59                              metavar='PASSWORD')
  60         self.settings.boolean(['lock-root-password'],
  61                               'lock root account so they cannot login?')
  62         self.settings.string(['customize'],
  63                              'run SCRIPT after setting up system',
  64                              metavar='SCRIPT')
  65         self.settings.string(['hostname'],
  66                              'set name to HOSTNAME (%default)',
  67                              metavar='HOSTNAME',
  68                              default='debian')
  69         self.settings.string_list(['user'],
  70                                   'create USER with PASSWORD',
  71                                   metavar='USER/PASSWORD')
  72         self.settings.boolean(['serial-console'],
  73                               'configure image to use a serial console')
  74         self.settings.boolean(['sudo'],
  75                               'install sudo, and if user is created, add them '
  76                                 'to sudo group')
  77
  78     def process_args(self, args):
  79         if not self.settings['image']:
  80             raise cliapp.AppException('You must give image filename.')
  81         if not self.settings['size']:
  82             raise cliapp.AppException('You must give image size.')
  83
  84         self.remove_dirs = []
  85         self.mount_points = []
  86
  87         try:
  88             self.create_empty_image()
  89             self.partition_image()
  90             self.install_mbr()
  91             rootdev = self.setup_kpartx()
  92             self.mkfs(rootdev)
  93             rootdir = self.mount(rootdev)
  94             self.debootstrap(rootdir)
  95             self.set_hostname(rootdir)
  96             self.create_fstab(rootdir)
  97             self.install_debs(rootdir)
  98             self.set_root_password(rootdir)
  99             self.create_users(rootdir)
 100             self.remove_udev_persistent_rules(rootdir)
 101             self.setup_networking(rootdir)
 102             self.install_extlinux(rootdev, rootdir)
 103             self.customize(rootdir)
 104         except BaseException, e:
 105             self.message('EEEK! Something bad happened...')
 106             self.cleanup_system()
 107             raise
 108         else:
 109             self.cleanup_system()
 110
 111     def message(self, msg):
 112         logging.info(msg)
 113         if self.settings['verbose']:
 114             print msg
 115
 116     def runcmd(self, argv, stdin='', ignore_fail=False, **kwargs):
 117         logging.debug('runcmd: %s %s' % (argv, kwargs))
 118         p = subprocess.Popen(argv, stdin=subprocess.PIPE,
 119                              stdout=subprocess.PIPE, stderr=subprocess.PIPE,
 120                              **kwargs)
 121         out, err = p.communicate(stdin)
 122         if p.returncode != 0:
 123             msg = 'command failed: %s\n%s\n%s' % (argv, out, err)
 124             logging.error(msg)
 125             if not ignore_fail:
 126                 raise cliapp.AppException(msg)
 127         return out
 128
 129     def mkdtemp(self):
 130         dirname = tempfile.mkdtemp()
 131         self.remove_dirs.append(dirname)
 132         logging.debug('mkdir %s' % dirname)
 133         return dirname
 134
 135     def mount(self, device):
 136         self.message('Mounting %s' % device)
 137         mount_point = self.mkdtemp()
 138         self.runcmd(['mount', device, mount_point])
 139         self.mount_points.append(mount_point)
 140         logging.debug('mounted %s on %s' % (device, mount_point))
 141         return mount_point
 142
 143     def create_empty_image(self):
 144         self.message('Creating disk image')
 145         self.runcmd(['qemu-img', 'create', '-f', 'raw',
 146                      self.settings['image'],
 147                      str(self.settings['size'])])
 148
 149     def partition_image(self):
 150         self.message('Creating partitions')
 151         self.runcmd(['parted', '-s', self.settings['image'],
 152                      'mklabel', 'msdos'])
 153         self.runcmd(['parted', '-s', self.settings['image'],
 154                      'mkpart', 'primary', '0%', '100%'])
 155         self.runcmd(['parted', '-s', self.settings['image'],
 156                      'set', '1', 'boot', 'on'])
 157
 158     def install_mbr(self):
 159         self.message('Installing MBR')
 160         self.runcmd(['install-mbr', self.settings['image']])
 161
 162     def setup_kpartx(self):
 163         out = self.runcmd(['kpartx', '-av', self.settings['image']])
 164         devices = [line.split()[2]
 165                    for line in out.splitlines()
 166                    if line.startswith('add map ')]
 167         if len(devices) != 1:
 168             raise cliapp.AppException('Surprising number of partitions')
 169         return '/dev/mapper/%s' % devices[0]
 170
 171     def mkfs(self, device):
 172         self.message('Creating filesystem')
 173         self.runcmd(['mkfs', '-t', 'ext2', device])
 174
 175     def debootstrap(self, rootdir):
 176         self.message('Debootstrapping')
 177
 178         include = self.settings['package']
 179
 180         if not self.settings['no-kernel']:
 181             if self.settings['arch'] == 'i386':
 182                 kernel_arch = '686'
 183             else:
 184                 kernel_arch = self.settings['arch']
 185             kernel_image = 'linux-image-2.6-%s' % kernel_arch
 186             include.append(kernel_image)
 187
 188         if self.settings['sudo'] and 'sudo' not in include:
 189             include.append('sudo')
 190
 191         self.runcmd(['debootstrap',
 192                      '--arch=%s' % self.settings['arch'],
 193                      '--include=%s' % ','.join(include),
 194                      self.settings['distribution'],
 195                      rootdir,
 196                      self.settings['mirror']])
 197
 198     def set_hostname(self, rootdir):
 199         hostname = self.settings['hostname']
 200         with open(os.path.join(rootdir, 'etc', 'hostname'), 'w') as f:
 201             f.write('%s\n' % hostname)
 202
 203         etc_hosts = os.path.join(rootdir, 'etc', 'hosts')
 204         with open(etc_hosts, 'r') as f:
 205             data = f.read()
 206         with open(etc_hosts, 'w') as f:
 207             for line in data.splitlines():
 208                 if line.startswith('127.0.0.1'):
 209                     line += ' %s' % hostname
 210                 f.write('%s\n' % line)
 211
 212     def create_fstab(self, rootdir):
 213         fstab = os.path.join(rootdir, 'etc', 'fstab')
 214         with open(fstab, 'w') as f:
 215             f.write('proc /proc proc defaults 0 0\n')
 216             f.write('/dev/sda1 / ext4 errors=remount-ro 0 1\n')
 217
 218     def install_debs(self, rootdir):
 219         if not self.settings['custom-package']:
 220             return
 221         self.message('Installing custom packages')
 222         tmp = os.path.join(rootdir, 'tmp', 'install_debs')
 223         os.mkdir(tmp)
 224         for deb in self.settings['custom-package']:
 225             shutil.copy(deb, tmp)
 226         filenames = [os.path.join('/tmp/install_debs', os.path.basename(deb))
 227                      for deb in self.settings['custom-package']]
 228         out, err, exit = \
 229             self.runcmd_unchecked(['chroot', rootdir, 'dpkg', '-i'] + filenames)
 230         logging.debug('stdout:\n%s' % out)
 231         logging.debug('stderr:\n%s' % err)
 232         out = self.runcmd(['chroot', rootdir,
 233                      'apt-get', '-f', '--no-remove', 'install'])
 234         logging.debug('stdout:\n%s' % out)
 235         shutil.rmtree(tmp)
 236
 237     def set_root_password(self, rootdir):
 238         if self.settings['root-password']:
 239             self.message('Setting root password')
 240             self.set_password(rootdir, 'root', self.settings['root-password'])
 241         elif self.settings['lock-root-password']:
 242             self.message('Locking root password')
 243             self.runcmd(['chroot', rootdir, 'passwd', '-l', 'root'])
 244         else:
 245             self.message('Give root an empty password')
 246             self.delete_password(rootdir, 'root')
 247
 248     def create_users(self, rootdir):
 249         def create_user(user):
 250             self.runcmd(['chroot', rootdir, 'adduser', '--gecos', user,
 251                          '--disabled-password', user])
 252             if self.settings['sudo']:
 253                 self.runcmd(['chroot', rootdir, 'adduser', user, 'sudo'])
 254
 255         for userpass in self.settings['user']:
 256             if '/' in userpass:
 257                 user, password = userpass.split('/', 1)
 258                 create_user(user)
 259                 self.set_password(rootdir, user, password)
 260             else:
 261                 create_user(userpass)
 262                 self.delete_password(rootdir, userpass)
 263
 264     def set_password(self, rootdir, user, password):
 265         encrypted = crypt.crypt(password, '..')
 266         self.runcmd(['chroot', rootdir, 'usermod', '-p', encrypted, user])
 267
 268     def delete_password(self, rootdir, user):
 269         self.runcmd(['chroot', rootdir, 'passwd', '-d', user])
 270
 271     def remove_udev_persistent_rules(self, rootdir):
 272         self.message('Removing udev persistent cd and net rules')
 273         for x in ['70-persistent-cd.rules', '70-persistent-net.rules']:
 274             pathname = os.path.join(rootdir, 'etc', 'udev', 'rules.d', x)
 275             if os.path.exists(pathname):
 276                 logging.debug('rm %s' % pathname)
 277                 os.remove(pathname)
 278             else:
 279                 logging.debug('not removing non-existent %s' % pathname)
 280
 281     def setup_networking(self, rootdir):
 282         self.message('Setting up networking')
 283
 284         f = open(os.path.join(rootdir, 'etc', 'network', 'interfaces'), 'w')
 285         f.write('auto lo\n')
 286         f.write('iface lo inet loopback\n')
 287
 288         if self.settings['enable-dhcp']:
 289             f.write('\n')
 290             f.write('allow-hotplug eth0\n')
 291             f.write('iface eth0 inet dhcp\n')
 292
 293         f.close()
 294
 295     def install_extlinux(self, rootdev, rootdir):
 296         self.message('Installing extlinux')
 297
 298         def find(pattern):
 299             dirname = os.path.join(rootdir, 'boot')
 300             basenames = os.listdir(dirname)
 301             logging.debug('find: %s' % basenames)
 302             for basename in basenames:
 303                 if re.search(pattern, basename):
 304                     return os.path.join('boot', basename)
 305             raise cliapp.AppException('Cannot find match: %s' % pattern)
 306
 307         kernel_image = find('vmlinuz-.*')
 308         initrd_image = find('initrd.img-.*')
 309
 310         out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 311                            '-s', 'UUID', rootdev])
 312         uuid = out.splitlines()[0].strip()
 313
 314         conf = os.path.join(rootdir, 'extlinux.conf')
 315         logging.debug('configure extlinux %s' % conf)
 316         f = open(conf, 'w')
 317         f.write('''
 318 default linux
 319 timeout 1
 320
 321 label linux
 322 kernel %(kernel)s
 323 append initrd=%(initrd)s root=UUID=%(uuid)s ro quiet %(kserial)s
 324 %(extserial)s
 325 ''' % {
 326     'kernel': kernel_image,
 327     'initrd': initrd_image,
 328     'uuid': uuid,
 329     'kserial':
 330         'console=ttyS0,115200' if self.settings['serial-console'] else '',
 331     'extserial': 'serial 0 115200' if self.settings['serial-console'] else '',
 332 })
 333         f.close()
 334
 335         if self.settings['serial-console']:
 336             logging.debug('adding getty to serial console')
 337             inittab = os.path.join(rootdir, 'etc/inittab')
 338             with open(inittab, 'a') as f:
 339                 f.write('\nS0:23:respawn:/sbin/getty -L ttyS0 115200 vt100\n')
 340
 341         self.runcmd(['extlinux', '--install', rootdir])
 342         self.runcmd(['sync'])
 343         import time; time.sleep(2)
 344
 345     def cleanup_system(self):
 346         # Clean up after any errors.
 347
 348         self.message('Cleaning up')
 349
 350         for mount_point in self.mount_points:
 351             self.runcmd(['umount', mount_point], ignore_fail=True)
 352
 353         self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True)
 354
 355         for dirname in self.remove_dirs:
 356             shutil.rmtree(dirname)
 357
 358     def customize(self, rootdir):
 359         script = self.settings['customize']
 360         if script:
 361             self.message('Running customize script %s' % script)
 362             with open('/dev/tty', 'w') as tty:
 363                 cliapp.runcmd([script, rootdir], stdout=tty, stderr=tty)
 364
 365
 366 if __name__ == '__main__':
 367     VmDebootstrap().run()
 368