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(['enable-dhcp'], 'enable DHCP on eth0')
  59         self.settings.string(['root-password'], 'set root password',
  60                              metavar='PASSWORD')
  61         self.settings.boolean(['lock-root-password'],
  62                               'lock root account so they cannot login?')
  63         self.settings.string(['customize'],
  64                              'run SCRIPT after setting up system',
  65                              metavar='SCRIPT')
  66         self.settings.string(['hostname'],
  67                              'set name to HOSTNAME (%default)',
  68                              metavar='HOSTNAME',
  69                              default='debian')
  70         self.settings.string_list(['user'],
  71                                   'create USER with PASSWORD',
  72                                   metavar='USER/PASSWORD')
  73         self.settings.boolean(['serial-console'],
  74                               'configure image to use a serial console')
  75         self.settings.boolean(['sudo'],
  76                               'install sudo, and if user is created, add them '
  77                                 'to sudo group')
  78
  79     def process_args(self, args):
  80         if not self.settings['image'] and not self.settings['tarball']:
  81             raise cliapp.AppException('You must give disk image filename, '
  82                                       'or tarball filename')
  83         if self.settings['image'] and not self.settings['size']:
  84             raise cliapp.AppException('If disk image is specified, '
  85                                       'You must give image size.')
  86
  87         self.remove_dirs = []
  88         self.mount_points = []
  89
  90         try:
  91             if self.settings['image']:
  92                 self.create_empty_image()
  93                 self.partition_image()
  94                 self.install_mbr()
  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             if self.settings['image']:
 109                 self.install_extlinux(rootdev, rootdir)
 110             self.customize(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 install_mbr(self):
 168         self.message('Installing MBR')
 169         self.runcmd(['install-mbr', self.settings['image']])
 170
 171     def setup_kpartx(self):
 172         out = self.runcmd(['kpartx', '-av', self.settings['image']])
 173         devices = [line.split()[2]
 174                    for line in out.splitlines()
 175                    if line.startswith('add map ')]
 176         if len(devices) != 1:
 177             raise cliapp.AppException('Surprising number of partitions')
 178         return '/dev/mapper/%s' % devices[0]
 179
 180     def mkfs(self, device):
 181         self.message('Creating filesystem')
 182         self.runcmd(['mkfs', '-t', 'ext2', device])
 183
 184     def debootstrap(self, rootdir):
 185         self.message('Debootstrapping')
 186
 187         if self.settings['arch'] == 'i386':
 188             kernel_arch = '686'
 189         else:
 190             kernel_arch = self.settings['arch']
 191         kernel_image = 'linux-image-2.6-%s' % kernel_arch
 192
 193         include = [kernel_image] + self.settings['package']
 194         if self.settings['sudo'] and 'sudo' not in include:
 195             include.append('sudo')
 196
 197         self.runcmd(['debootstrap',
 198                      '--arch=%s' % self.settings['arch'],
 199                      '--include=%s' % ','.join(include),
 200                      self.settings['distribution'],
 201                      rootdir,
 202                      self.settings['mirror']])
 203
 204     def set_hostname(self, rootdir):
 205         hostname = self.settings['hostname']
 206         with open(os.path.join(rootdir, 'etc', 'hostname'), 'w') as f:
 207             f.write('%s\n' % hostname)
 208
 209         etc_hosts = os.path.join(rootdir, 'etc', 'hosts')
 210         with open(etc_hosts, 'r') as f:
 211             data = f.read()
 212         with open(etc_hosts, 'w') as f:
 213             for line in data.splitlines():
 214                 if line.startswith('127.0.0.1'):
 215                     line += ' %s' % hostname
 216                 f.write('%s\n' % line)
 217
 218     def create_fstab(self, rootdir):
 219         fstab = os.path.join(rootdir, 'etc', 'fstab')
 220         with open(fstab, 'w') as f:
 221             f.write('proc /proc proc defaults 0 0\n')
 222             f.write('/dev/sda1 / ext4 errors=remount-ro 0 1\n')
 223
 224     def install_debs(self, rootdir):
 225         if not self.settings['custom-package']:
 226             return
 227         self.message('Installing custom packages')
 228         tmp = os.path.join(rootdir, 'tmp', 'install_debs')
 229         os.mkdir(tmp)
 230         for deb in self.settings['custom-package']:
 231             shutil.copy(deb, tmp)
 232         filenames = [os.path.join('/tmp/install_debs', os.path.basename(deb))
 233                      for deb in self.settings['custom-package']]
 234         out, err, exit = \
 235             self.runcmd_unchecked(['chroot', rootdir, 'dpkg', '-i'] + filenames)
 236         logging.debug('stdout:\n%s' % out)
 237         logging.debug('stderr:\n%s' % err)
 238         out = self.runcmd(['chroot', rootdir,
 239                      'apt-get', '-f', '--no-remove', 'install'])
 240         logging.debug('stdout:\n%s' % out)
 241         shutil.rmtree(tmp)
 242
 243     def set_root_password(self, rootdir):
 244         if self.settings['root-password']:
 245             self.message('Setting root password')
 246             self.set_password(rootdir, 'root', self.settings['root-password'])
 247         elif self.settings['lock-root-password']:
 248             self.message('Locking root password')
 249             self.runcmd(['chroot', rootdir, 'passwd', '-l', 'root'])
 250         else:
 251             self.message('Give root an empty password')
 252             self.delete_password(rootdir, 'root')
 253
 254     def create_users(self, rootdir):
 255         def create_user(user):
 256             self.runcmd(['chroot', rootdir, 'adduser', '--gecos', user,
 257                          '--disabled-password', user])
 258             if self.settings['sudo']:
 259                 self.runcmd(['chroot', rootdir, 'adduser', user, 'sudo'])
 260
 261         for userpass in self.settings['user']:
 262             if '/' in userpass:
 263                 user, password = userpass.split('/', 1)
 264                 create_user(user)
 265                 self.set_password(rootdir, user, password)
 266             else:
 267                 create_user(userpass)
 268                 self.delete_password(rootdir, userpass)
 269
 270     def set_password(self, rootdir, user, password):
 271         encrypted = crypt.crypt(password, '..')
 272         self.runcmd(['chroot', rootdir, 'usermod', '-p', encrypted, user])
 273
 274     def delete_password(self, rootdir, user):
 275         self.runcmd(['chroot', rootdir, 'passwd', '-d', user])
 276
 277     def remove_udev_persistent_rules(self, rootdir):
 278         self.message('Removing udev persistent cd and net rules')
 279         for x in ['70-persistent-cd.rules', '70-persistent-net.rules']:
 280             pathname = os.path.join(rootdir, 'etc', 'udev', 'rules.d', x)
 281             if os.path.exists(pathname):
 282                 logging.debug('rm %s' % pathname)
 283                 os.remove(pathname)
 284             else:
 285                 logging.debug('not removing non-existent %s' % pathname)
 286
 287     def setup_networking(self, rootdir):
 288         self.message('Setting up networking')
 289
 290         f = open(os.path.join(rootdir, 'etc', 'network', 'interfaces'), 'w')
 291         f.write('auto lo\n')
 292         f.write('iface lo inet loopback\n')
 293
 294         if self.settings['enable-dhcp']:
 295             f.write('\n')
 296             f.write('allow-hotplug eth0\n')
 297             f.write('iface eth0 inet dhcp\n')
 298
 299         f.close()
 300
 301     def install_extlinux(self, rootdev, rootdir):
 302         self.message('Installing extlinux')
 303
 304         def find(pattern):
 305             dirname = os.path.join(rootdir, 'boot')
 306             basenames = os.listdir(dirname)
 307             logging.debug('find: %s' % basenames)
 308             for basename in basenames:
 309                 if re.search(pattern, basename):
 310                     return os.path.join('boot', basename)
 311             raise cliapp.AppException('Cannot find match: %s' % pattern)
 312
 313         kernel_image = find('vmlinuz-.*')
 314         initrd_image = find('initrd.img-.*')
 315
 316         out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 317                            '-s', 'UUID', rootdev])
 318         uuid = out.splitlines()[0].strip()
 319
 320         conf = os.path.join(rootdir, 'extlinux.conf')
 321         logging.debug('configure extlinux %s' % conf)
 322         f = open(conf, 'w')
 323         f.write('''
 324 default linux
 325 timeout 1
 326
 327 label linux
 328 kernel %(kernel)s
 329 append initrd=%(initrd)s root=UUID=%(uuid)s ro quiet %(kserial)s
 330 %(extserial)s
 331 ''' % {
 332     'kernel': kernel_image,
 333     'initrd': initrd_image,
 334     'uuid': uuid,
 335     'kserial':
 336         'console=ttyS0,115200' if self.settings['serial-console'] else '',
 337     'extserial': 'serial 0 115200' if self.settings['serial-console'] else '',
 338 })
 339         f.close()
 340
 341         if self.settings['serial-console']:
 342             logging.debug('adding getty to serial console')
 343             inittab = os.path.join(rootdir, 'etc/inittab')
 344             with open(inittab, 'a') as f:
 345                 f.write('\nS0:23:respawn:/sbin/getty -L ttyS0 115200 vt100\n')
 346
 347         self.runcmd(['extlinux', '--install', rootdir])
 348         self.runcmd(['sync'])
 349         import time; time.sleep(2)
 350
 351     def cleanup_system(self):
 352         # Clean up after any errors.
 353
 354         self.message('Cleaning up')
 355
 356         if self.settings['image']:
 357             for mount_point in self.mount_points:
 358                 self.runcmd(['umount', mount_point], ignore_fail=True)
 359
 360             self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True)
 361
 362         for dirname in self.remove_dirs:
 363             shutil.rmtree(dirname)
 364
 365     def customize(self, rootdir):
 366         script = self.settings['customize']
 367         if script:
 368             self.message('Running customize script %s' % script)
 369             with open('/dev/tty', 'w') as tty:
 370                 cliapp.runcmd([script, rootdir], stdout=tty, stderr=tty)
 371
 372     def create_tarball(self, rootdir):
 373         # Create a tarball of the disk's contents
 374         # shell out to runcmd since it more easily handles rootdir
 375         self.message('Creating tarball of disk contents')
 376         self.runcmd(['tar', '-cf', self.settings['tarball'], '-C', rootdir, '.'])
 377
 378
 379 if __name__ == '__main__':
 380     VmDebootstrap().run()
 381