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