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