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