tools/liveimage-mount

   1 #!/usr/bin/python -tt
   2 #
   3 # liveimage-mount: Mount a LiveOS at the specified point, and log
   4 # into a shell.
   5 #
   6 # Copyright 2011, Red Hat  Inc.
   7 #   Code for Live mounting an attached LiveOS device added by Frederick Grose,
   8 #   <fgrose at sugarlabs.org>
   9 #
  10 # This program is free software; you can redistribute it and/or modify
  11 # it under the terms of the GNU General Public License as published by
  12 # the Free Software Foundation; version 2 of the License.
  13 #
  14 # This program is distributed in the hope that it will be useful,
  15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 # GNU Library General Public License for more details.
  18 #
  19 # You should have received a copy of the GNU General Public License
  20 # along with this program; if not, write to the Free Software
  21 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22
  23 import os
  24 import sys
  25 import stat
  26 import getopt
  27 import tempfile
  28 import subprocess
  29
  30
  31 def usage(ecode):
  32     print """Usage:
  33         liveimage-mount [opts] ISO.iso|LiveOSdevice MOUNTPOINT [COMMAND] [ARGS]
  34
  35                   where [opts] = [-h|--help
  36                                  [--chroot
  37                                  [--mount-hacks
  38                                  [--persist]]]]]
  39
  40                     and [ARGS] = [arg1[ arg2[ ...]]]\n"""
  41     sys.exit(ecode)
  42
  43
  44 def call(*popenargs, **kwargs):
  45     '''
  46         Calls subprocess.Popen() with the provided arguments.  All stdout and
  47         stderr output is sent to print.  The return value is the exit
  48         code of the command.
  49     '''
  50     p = subprocess.Popen(*popenargs, stdout=subprocess.PIPE,
  51                          stderr=subprocess.STDOUT, **kwargs)
  52     rc = p.wait()
  53
  54     # Log output using logging module
  55     while True:
  56         # FIXME choose a more appropriate buffer size
  57         buf = p.stdout.read(4096)
  58         if not buf:
  59             break
  60         print buf
  61
  62     return rc
  63
  64
  65 def rcall(args, env=None):
  66     if env:
  67         environ = os.environ.copy()
  68         environ.update(env)
  69     else:
  70         environ = None
  71     try:
  72         p = subprocess.Popen(args, stdout=subprocess.PIPE,
  73                              stderr=subprocess.PIPE, env=environ)
  74         out, err = p.communicate()
  75     except OSError, e:
  76         raise CreatorError(u"Failed to execute:\n'%s'\n'%s'" % (args, e))
  77     except:
  78         raise CreatorError(u"""Failed to execute:\n'%s'
  79             \renviron: '%s'\nstdout: '%s'\nstderr: '%s'\nreturncode: '%s'""" %
  80             (args, environ, out, err, p.returncode))
  81     else:
  82         if p.returncode != 0:
  83             raise CreatorError(u"""Error in call:\n'%s'\nenviron: '%s'
  84                 \rstdout: '%s'\nstderr: '%s'\nreturncode: '%s'""" %
  85                 (args, environ, out, err, p.returncode))
  86         return out
  87
  88
  89 def get_device_mountpoint(path):
  90     """Return the device and mountpoint for a file or device path."""
  91
  92     info = list()
  93     info[0:5] = [None] * 6
  94     if os.path.exists(path):
  95         st_mode = os.stat(path).st_mode
  96         if stat.S_ISBLK(st_mode) or os.path.ismount(path):
  97             devinfo = rcall(['/bin/df', path]).splitlines()
  98             info = devinfo[1].split(None)
  99             if len(info) == 1:
 100                 info.extend(devinfo[2].split(None))
 101     return [info[0], info[5]]
 102
 103
 104 def main():
 105     if os.geteuid() != 0:
 106         print >> sys.stderr, """\n  Exiting...
 107         \r  You must run liveimage-mount with root priviledges.\n"""
 108         return 1
 109
 110     try:
 111         opts,args = getopt.getopt(sys.argv[1:], 'h', ['help',
 112                                                        'chroot', 'persist',
 113                                                        'mount-hacks'])
 114     except getopt.GetoptError, e:
 115         usage(1)
 116
 117     img_type = None
 118     chroot = False
 119     persist = False
 120     mount_hacks = False
 121     for o,a in opts:
 122         if o in ('-h', '--help'):
 123             usage(0)
 124         elif o in ('--chroot', ):
 125             chroot = True
 126         elif o in ('--mount-hacks', ):
 127             mount_hacks = True
 128         elif o in ('--persist', ):
 129             """Option used to run a command in a spawned process."""
 130             persist = True
 131
 132     if len(args) < 2:
 133         usage(1)
 134
 135     liveos = args[0]
 136     destmnt = args[1]
 137
 138     if not os.path.exists(liveos):
 139         print """\n     Exiting...
 140         %s is not a file, directory, or device.\n""" % liveos
 141         ecode = 1
 142         return
 143
 144     if stat.S_ISBLK(os.stat(liveos).st_mode):
 145         img_type = 'blk'
 146         imgloop = None
 147         overlayloop = None
 148     else:
 149         img_type = 'iso'
 150
 151     if img_type is 'blk':
 152         liveosmnt = tempfile.mkdtemp(prefix='livemnt-device-')
 153     if img_type is 'iso':
 154         liveosmnt = tempfile.mkdtemp(prefix='livemnt-iso-')
 155
 156     liveosdir = os.path.join(liveosmnt, 'LiveOS')
 157     homemnt = None
 158     dm_cow = None
 159     mntlive = None
 160
 161     command = args[2:]
 162     verbose = not command
 163
 164     squashmnt = tempfile.mkdtemp(prefix='livemnt-squash-')
 165     squashloop = None
 166     imgloop = None
 167     losetup_args = ['/sbin/losetup', '-f', '--show']
 168
 169     try:
 170         if img_type is 'blk':
 171             call(['/bin/mount', liveos, liveosmnt])
 172         elif img_type is 'iso':
 173             liveosloop = rcall(losetup_args + [liveos]).rstrip()
 174             call(['/bin/mount', '-o', 'ro', liveosloop, liveosmnt])
 175
 176         squash_img = os.path.join(liveosdir, 'squashfs.img')
 177         if not os.path.exists(squash_img):
 178             ext3_img = os.path.join(liveosdir, 'ext3fs.img')
 179             if not os.path.exists(ext3_img):
 180                 print """
 181                 \r\tNo LiveOS was found on %s\n\t  Exiting...\n""" % liveos
 182                 ecode = 1
 183                 return
 184         else:
 185             squashloop = rcall(losetup_args + [squash_img]).rstrip()
 186             call(['/bin/mount', '-o', 'ro', squashloop, squashmnt])
 187             ext3_img = os.path.join(squashmnt, 'LiveOS', 'ext3fs.img')
 188
 189         if img_type is 'blk':
 190             imgloop = rcall(losetup_args + [ext3_img]).rstrip()
 191             imgsize = rcall(['/sbin/blockdev', '--getsz', imgloop]).rstrip()
 192             files = os.listdir(liveosdir)
 193             overlay = None
 194             for f in files:
 195                 if f.find('overlay-') == 0:
 196                     overlay = f
 197                     break
 198             overlayloop = rcall(['/sbin/losetup', '-f']).rstrip()
 199             if overlay:
 200                 call(['/sbin/losetup', overlayloop, os.path.join(liveosdir,
 201                                                                  overlay)])
 202                 dm_cow = 'live-rw'
 203             else:
 204                 overlay = tempfile.NamedTemporaryFile(dir='/dev/shm')
 205                 print "\npreparing temporary overlay..."
 206                 call(['/bin/dd', 'if=/dev/null', 'of=%s' % overlay.name,
 207                       'bs=1024', 'count=1', 'seek=%s' % (512 * 1024)])
 208                 call(['/sbin/losetup', overlayloop, overlay.name])
 209                 dm_cow = 'live-ro'
 210             call(['/sbin/dmsetup', '--noudevrules', '--noudevsync',
 211                  'create', dm_cow, '--table=0 %s snapshot %s %s p 8' %
 212                  (imgsize, imgloop, overlayloop)])
 213             call(['/bin/mount', os.path.join('/dev/mapper', dm_cow), destmnt])
 214             home_path = os.path.join(liveosdir, 'home.img')
 215             if os.path.exists(home_path):
 216                 homemnt = os.path.join(destmnt, 'home')
 217                 homeloop = rcall(losetup_args + [home_path]).rstrip()
 218                 call(['/bin/mount', homeloop, homemnt])
 219             mntlive = os.path.join(destmnt, 'mnt', 'live')
 220             if not os.path.exists(mntlive):
 221                 os.makedirs(mntlive)
 222             call(['/bin/mount', '--bind', liveosmnt, mntlive])
 223         elif img_type is 'iso':
 224             imgloop = rcall(losetup_args + [ext3_img]).rstrip()
 225             call(['/bin/mount', '-o', 'ro', imgloop, destmnt])
 226
 227         if mount_hacks:
 228             subprocess.check_call(['mount', '-t', 'proc', 'proc', os.path.join(destmnt, 'proc')], stderr=sys.stderr)
 229             subprocess.check_call(['mount', '-t', 'tmpfs', 'tmpfs', os.path.join(destmnt, 'var', 'run')], stderr=sys.stderr)
 230
 231         if len(command) > 0 and persist:
 232             args = []
 233             args.extend(command)
 234             live = ''
 235             if img_type is 'blk':
 236                 live = 'live-'
 237             print """Starting process with this command line:
 238             \r%s\n  %s is %smounted.""" % (' '.join(command), liveos, live)
 239             p = subprocess.Popen(args, close_fds=True)
 240             print "Process id: %s" % p.pid
 241             ecode = p.returncode
 242         elif len(command) > 0:
 243             args = ['chroot', destmnt]
 244             args.extend(command)
 245             ecode = subprocess.call(args, stdin=sys.stdin, stdout=sys.stdout, stderr=sys.stderr)
 246         elif chroot:
 247             print "Starting subshell in chroot, press Ctrl-D to exit..."
 248             ecode = subprocess.call(['chroot', destmnt], stdin=sys.stdin, stdout=sys.stdout, stderr=sys.stderr)
 249         else:
 250             if dm_cow == 'live-ro':
 251                 status = ' with NO LiveOS persistence,'
 252             else:
 253                 status = ''
 254             print "Entering subshell,%s press Ctrl-D to exit..." % status
 255             ecode = subprocess.call([os.environ['SHELL']], cwd=destmnt, stdin=sys.stdin, stdout=sys.stdout, stderr=sys.stderr)
 256     finally:
 257         call(['/bin/sync'])
 258         if not persist:
 259             if verbose:
 260                 print """Cleaning up...
 261                 Please wait if large files were written."""
 262             if mount_hacks:
 263                 subprocess.call(['umount', os.path.join(destmnt, 'var', 'run')])
 264                 subprocess.call(['umount', os.path.join(destmnt, 'proc')])
 265             if homemnt:
 266                 call(['/bin/umount', homemnt])
 267                 call(['/sbin/losetup', '-d', homeloop])
 268             if img_type is 'blk':
 269                 if mntlive:
 270                     call(['/bin/umount', mntlive])
 271                     os.rmdir(mntlive)
 272             if os.path.ismount(destmnt):
 273                 call(['/bin/umount', destmnt])
 274             if img_type is 'blk':
 275      m_cow:
 276                     call(['/sbin/dmsetup', '--noudevrules', '--noudevsync',
 277                           'remove', dm_cow])
 278                 if overlayloop:
 279                     call(['/sbin/losetup', '-d', overlayloop])
 280             if imgloop:
 281                 call(['/sbin/losetup', '-d', imgloop])
 282             if squashloop:
 283                 call(['/bin/umount', squashloop])
 284                 call(['/sbin/losetup', '-d', squashloop])
 285             call(['/bin/umount', liveosmnt])
 286             if not img_type is 'blk':
 287                 call(['/sbin/losetup', '-d', liveosloop])
 288             os.rmdir(squashmnt)
 289             if not os.path.ismount(liveosmnt):
 290                 os.rmdir(liveosmnt)
 291             if verbose:
 292                 print "Cleanup complete"
 293
 294     sys.exit(ecode)
 295
 296 if __name__ == '__main__':
 297     main()