vmdebootstrap

   1 #!/usr/bin/python
   2 # Copyright 2011  Lars Wirzenius
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 import cliapp
  18 import crypt
  19 import logging
  20 import os
  21 import re
  22 import shutil
  23 import subprocess
  24 import tempfile
  25
  26
  27 class VmDebootstrap(cliapp.Application):
  28
  29     def add_settings(self):
  30         default_arch = 'amd64'
  31
  32         self.settings.boolean(['verbose'], 'report what is going on')
  33         self.settings.string(['image'], 'put created disk image in FILE',
  34                              metavar='FILE')
  35         self.settings.bytesize(['size'],
  36                                'create a disk image of size SIZE (%default)',
  37                                metavar='SIZE',
  38                                default='1G')
  39         self.settings.string(['mirror'],
  40                              'use MIRROR as package source (%default)',
  41                              metavar='URL',
  42                              default='http://cdn.debian.net/debian/')
  43         self.settings.string(['arch'], 'architecture to use (%default)',
  44                              metavar='ARCH',
  45                              default=default_arch)
  46         self.settings.string(['distribution'],
  47                              'release to use (%default)',
  48                              metavar='NAME',
  49                              default='stable')
  50         self.settings.string_list(['package'], 'install PACKAGE onto system')
  51         self.settings.string_list(['custom-package'],
  52                                   'install package in DEB file onto system '
  53                                     '(not from mirror)',
  54                                   metavar='DEB')
  55         self.settings.boolean(['enable-dhcp'], 'enable DHCP on eth0')
  56         self.settings.string(['root-password'], 'set root password',
  57                              metavar='PASSWORD')
  58         self.settings.boolean(['lock-root-password'],
  59                               'lock root account so they cannot login?')
  60         self.settings.string(['customize'],
  61                              'run SCRIPT after setting up system',
  62                              metavar='SCRIPT')
  63         self.settings.string(['hostname'],
  64                              'set name to HOSTNAME (%default)',
  65                              metavar='HOSTNAME',
  66                              default='debian')
  67         self.settings.string_list(['user'],
  68                                   'create USER with PASSWORD',
  69                                   metavar='USER/PASSWORD')
  70         self.settings.boolean(['serial-console'],
  71                               'configure image to use a serial console')
  72         self.settings.boolean(['sudo'],
  73                               'install sudo, and if user is created, add them '
  74                                 'to sudo group')
  75
  76     def process_args(self, args):
  77         if not self.settings['image']:
  78             raise cliapp.AppException('You must give image filename.')
  79         if not self.settings['size']:
  80             raise cliapp.AppException('You must give image size.')
  81
  82         self.remove_dirs = []
  83         self.mount_points = []
  84
  85         try:
  86             self.create_empty_image()
  87             self.partition_image()
  88             self.install_mbr()
  89             rootdev = self.setup_kpartx()
  90             self.mkfs(rootdev)
  91             rootdir = self.mount(rootdev)
  92             self.debootstrap(rootdir)
  93             self.set_hostname(rootdir)
  94             self.create_fstab(rootdir)
  95             self.install_debs(rootdir)
  96             self.set_root_password(rootdir)
  97             self.create_users(rootdir)
  98             self.remove_udev_persistent_rules(rootdir)
  99             self.setup_networking(rootdir)
 100             self.install_extlinux(rootdev, rootdir)
 101             self.customize(rootdir)
 102         except BaseException, e:
 103             self.message('EEEK! Something bad happened...')
 104             self.cleanup_system()
 105             raise
 106         else:
 107             self.cleanup_system()
 108
 109     def message(self, msg):
 110         if self.settings['verbose']:
 111             print msg
 112
 113     def runcmd(self, argv, stdin='', ignore_fail=False, **kwargs):
 114         logging.debug('runcmd: %s %s' % (argv, kwargs))
 115         p = subprocess.Popen(argv, stdin=subprocess.PIPE,
 116                              stdout=subprocess.PIPE, stderr=subprocess.PIPE,
 117                              **kwargs)
 118         out, err = p.communicate(stdin)
 119         if p.returncode != 0:
 120             msg = 'command failed: %s\n%s\n%s' % (argv, out, err)
 121             logging.error(msg)
 122             if not ignore_fail:
 123                 raise cliapp.AppException(msg)
 124         return out
 125
 126     def mkdtemp(self):
 127         dirname = tempfile.mkdtemp()
 128         self.remove_dirs.append(dirname)
 129         logging.debug('mkdir %s' % dirname)
 130         return dirname
 131
 132     def mount(self, device):
 133         self.message('Mounting %s' % device)
 134         mount_point = self.mkdtemp()
 135         self.runcmd(['mount', device, mount_point])
 136         self.mount_points.append(mount_point)
 137         logging.debug('mounted %s on %s' % (device, mount_point))
 138         return mount_point
 139
 140     def create_empty_image(self):
 141         self.message('Creating disk image')
 142         self.runcmd(['qemu-img', 'create', '-f', 'raw',
 143                      self.settings['image'],
 144                      str(self.settings['size'])])
 145
 146     def partition_image(self):
 147         self.message('Creating partitions')
 148         self.runcmd(['parted', '-s', self.settings['image'],
 149                      'mklabel', 'msdos'])
 150         self.runcmd(['parted', '-s', self.settings['image'],
 151                      'mkpart', 'primary', '0%', '100%'])
 152         self.runcmd(['parted', '-s', self.settings['image'],
 153                      'set', '1', 'boot', 'on'])
 154
 155     def install_mbr(self):
 156         self.message('Installing MBR')
 157         self.runcmd(['install-mbr', self.settings['image']])
 158
 159     def setup_kpartx(self):
 160         out = self.runcmd(['kpartx', '-av', self.settings['image']])
 161         devices = [line.split()[2]
 162                    for line in out.splitlines()
 163                    if line.startswith('add map ')]
 164         if len(devices) != 1:
 165             raise cliapp.AppException('Surprising number of partitions')
 166         return '/dev/mapper/%s' % devices[0]
 167
 168     def mkfs(self, device):
 169         self.message('Creating filesystem')
 170         self.runcmd(['mkfs', '-t', 'ext2', device])
 171
 172     def debootstrap(self, rootdir):
 173         self.message('Debootstrapping')
 174
 175         if self.settings['arch'] == 'i386':
 176             kernel_arch = '686'
 177         else:
 178             kernel_arch = self.settings['arch']
 179         kernel_image = 'linux-image-2.6-%s' % kernel_arch
 180
 181         include = [kernel_image] + self.settings['package']
 182         if self.settings['sudo'] and 'sudo' not in include:
 183             include.append('sudo')
 184
 185         self.runcmd(['debootstrap',
 186                      '--arch=%s' % self.settings['arch'],
 187                      '--include=%s' % ','.join(include),
 188                      self.settings['distribution'],
 189                      rootdir,
 190                      self.settings['mirror']])
 191
 192     def set_hostname(self, rootdir):
 193         hostname = self.settings['hostname']
 194         with open(os.path.join(rootdir, 'etc', 'hostname'), 'w') as f:
 195             f.write('%s\n' % hostname)
 196
 197         etc_hosts = os.path.join(rootdir, 'etc', 'hosts')
 198         with open(etc_hosts, 'r') as f:
 199             data = f.read()
 200         with open(etc_hosts, 'w') as f:
 201             for line in data.splitlines():
 202                 if line.startswith('127.0.0.1'):
 203                     line += ' %s' % hostname
 204                 f.write('%s\n' % line)
 205
 206     def create_fstab(self, rootdir):
 207         fstab = os.path.join(rootdir, 'etc', 'fstab')
 208         with open(fstab, 'w') as f:
 209             f.write('proc /proc proc defaults 0 0\n')
 210             f.write('/dev/sda1 / ext4 errors=remount-ro 0 1\n')
 211
 212     def install_debs(self, rootdir):
 213         if not self.settings['custom-package']:
 214             return
 215         self.message('Installing custom packages')
 216         tmp = os.path.join(rootdir, 'tmp', 'install_debs')
 217         os.mkdir(tmp)
 218         for deb in self.settings['custom-package']:
 219             shutil.copy(deb, tmp)
 220         filenames = [os.path.join('/tmp/install_debs', os.path.basename(deb))
 221                      for deb in self.settings['custom-package']]
 222         out, err, exit = \
 223             self.runcmd_unchecked(['chroot', rootdir, 'dpkg', '-i'] + filenames)
 224         logging.debug('stdout:\n%s' % out)
 225         logging.debug('stderr:\n%s' % err)
 226         out = self.runcmd(['chroot', rootdir,
 227                      'apt-get', '-f', '--no-remove', 'install'])
 228         logging.debug('stdout:\n%s' % out)
 229         shutil.rmtree(tmp)
 230
 231     def set_root_password(self, rootdir):
 232         if self.settings['root-password']:
 233             self.message('Setting root password')
 234             self.set_password(rootdir, 'root', self.settings['root-password'])
 235         elif self.settings['lock-root-password']:
 236             self.message('Locking root password')
 237             self.runcmd(['chroot', rootdir, 'passwd', '-l', 'root'])
 238         else:
 239             self.message('Give root an empty password')
 240             self.runcmd(['chroot', rootdir, 'passwd', '-d', 'root'])
 241
 242     def create_users(self, rootdir):
 243         def create_user(user):
 244             self.runcmd(['chroot', rootdir, 'adduser', '--gecos', user,
 245                          '--disabled-password', user])
 246             if self.settings['sudo']:
 247                 self.runcmd(['chroot', rootdir, 'adduser', user, 'sudo'])
 248
 249         for userpass in self.settings['user']:
 250             if '/' in userpass:
 251                 user, password = userpass.split('/', 1)
 252                 create_user(user)
 253                 self.set_password(rootdir, user, password)
 254             else:
 255                 create_user(userpass)
 256
 257     def set_password(self, rootdir, user, password):
 258         encrypted = crypt.crypt(password, '..')
 259         self.runcmd(['chroot', rootdir, 'usermod', '-p', encrypted, user])
 260
 261     def remove_udev_persistent_rules(self, rootdir):
 262         self.message('Removing udev persistent cd and net rules')
 263         for x in ['70-persistent-cd.rules', '70-persistent-net.rules']:
 264             pathname = os.path.join(rootdir, 'etc', 'udev', 'rules.d', x)
 265             if os.path.exists(pathname):
 266                 logging.debug('rm %s' % pathname)
 267                 os.remove(pathname)
 268             else:
 269                 logging.debug('not removing non-existent %s' % pathname)
 270
 271     def setup_networking(self, rootdir):
 272         self.message('Setting up networking')
 273
 274         f = open(os.path.join(rootdir, 'etc', 'network', 'interfaces'), 'w')
 275         f.write('auto lo\n')
 276         f.write('iface lo inet loopback\n')
 277
 278         if self.settings['enable-dhcp']:
 279             f.write('\n')
 280             f.write('allow-hotplug eth0\n')
 281             f.write('iface eth0 inet dhcp\n')
 282
 283         f.close()
 284
 285     def install_extlinux(self, rootdev, rootdir):
 286         self.message('Installing extlinux')
 287
 288         def find(pattern):
 289             dirname = os.path.join(rootdir, 'boot')
 290             basenames = os.listdir(dirname)
 291             logging.debug('find: %s' % basenames)
 292             for basename in basenames:
 293                 if re.search(pattern, basename):
 294                     return os.path.join('boot', basename)
 295             raise cliapp.AppException('Cannot find match: %s' % pattern)
 296
 297         kernel_image = find('vmlinuz-.*')
 298         initrd_image = find('initrd.img-.*')
 299
 300         out = self.runcmd(['blkid', '-c', '/dev/null', '-o', 'value',
 301                            '-s', 'UUID', rootdev])
 302         uuid = out.splitlines()[0].strip()
 303
 304         conf = os.path.join(rootdir, 'extlinux.conf')
 305         logging.debug('configure extlinux %s' % conf)
 306         f = open(conf, 'w')
 307         f.write('''
 308 default linux
 309 timeout 1
 310
 311 label linux
 312 kernel %(kernel)s
 313 append initrd=%(initrd)s root=UUID=%(uuid)s ro quiet %(kserial)s
 314 %(extserial)s
 315 ''' % {
 316     'kernel': kernel_image,
 317     'initrd': initrd_image,
 318     'uuid': uuid,
 319     'kserial':
 320         'console=ttyS0,115200' if self.settings['serial-console'] else '',
 321     'extserial': 'serial 0 115200' if self.settings['serial-console'] else '',
 322 })
 323         f.close()
 324
 325         if self.settings['serial-console']:
 326             logging.debug('adding getty to serial console')
 327             inittab = os.path.join(rootdir, 'etc/inittab')
 328             with open(inittab, 'a') as f:
 329                 f.write('\nS0:23:respawn:/sbin/getty -L ttyS0 115200 vt100\n')
 330
 331         self.runcmd(['extlinux', '--install', rootdir])
 332         self.runcmd(['sync'])
 333         import time; time.sleep(2)
 334
 335     def cleanup_system(self):
 336         # Clean up after any errors.
 337
 338         self.message('Cleaning up')
 339
 340         for mount_point in self.mount_points:
 341             self.runcmd(['umount', mount_point], ignore_fail=True)
 342
 343         self.runcmd(['kpartx', '-d', self.settings['image']], ignore_fail=True)
 344
 345         for dirname in self.remove_dirs:
 346             shutil.rmtree(dirname)
 347
 348     def customize(self, rootdir):
 349         script = self.settings['customize']
 350         if script:
 351             self.message('Running customize script %s' % script)
 352             self.runcmd([script, rootdir])
 353
 354
 355 if __name__ == '__main__':
 356     VmDebootstrap().run()
 357