bin/live-snapshot

   1 #! /bin/bash
   2
   3 # casper-snapshot - utility to manage Debian Live systems snapshots
   4 #
   5 #   This program mount a device (fallback to /tmpfs under /mnt/snapshot
   6 #   and save the /cow (or a different dir) filesystem in it for reusing
   7 #   in another casper session. Look at manpage for more info.
   8 #
   9 # Copyright (C) 2006 Marco Amadori <marco.amadori@gmail.com>
  10 #
  11 # This program is free software; you can redistribute it and/or modify
  12 # it under the terms of the GNU General Public License as published by
  13 # the Free Software Foundation; either version 2 of the License, or
  14 # (at your option) any later version.
  15 #
  16 # This program is distributed in the hope that it will be useful,
  17 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19 # GNU General Public License for more details.
  20 #
  21 # You should have received a copy of the GNU General Public License
  22 # along with this program; if not, write to the Free Software
  23 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  24 #
  25 # On Debian systems, the complete text of the GNU General Public License
  26 # can be found in /usr/share/common-licenses/GPL file.
  27
  28 PROGRAM="`basename $0`"
  29 VERSION=0.0.1
  30
  31
  32 # Source live conf
  33 if [ -e /etc/live.conf ]; then
  34         . /etc/live.conf
  35 else
  36         USERNAME=$(cat /etc/passwd | grep "999" | cut -f1 -d ':')
  37         HOSTNAME=$(hostname)
  38         BUILD_SYSTEM="Debian"
  39 fi
  40
  41 export USERNAME USERFULLNAME HOSTNAME BUILD_SYSTEM
  42
  43 # Source helper functions
  44 helpers="/usr/share/initramfs-tools/scripts/live-helpers"
  45 if [ -e "${helpers}" ]; then
  46         . "${helpers}"
  47 else
  48         echo "Error: I cannot found helper functions \"${helpers}\"."
  49         exit 1
  50 fi
  51
  52 # Define LSB log_* functions.
  53 # Depend on lsb-base (>= 3.0-6) to ensure that this file is present.
  54 . /lib/lsb/init-functions
  55
  56 MOUNTP=""
  57 COW=""
  58 DEV=""
  59 DEST=""
  60 TYPE=""
  61 DESKTOP_LINK=""
  62
  63 Header ()
  64 {
  65         echo "${PROGRAM} - utility to do Debian Live snapshots"
  66         echo
  67         echo "Usage: ${PROGRAM} [-c|--cow DIRECTORY] [-d|--device DEVICE] [-o|--output FILE] [-t|--type TYPE]"
  68         echo "Usage: ${PROGRAM} [-r|--resync-string STRING]"
  69         echo "Usage: ${PROGRAM} [-h|--help]"
  70         echo "Usage: ${PROGRAM} [-u|--usage]"
  71         echo "Usage: ${PROGRAM} [-v|--version]"
  72 }
  73
  74 Usage ()
  75 {
  76         MESSAGE=${1}
  77         Header
  78         echo
  79         echo "Try \"${PROGRAM} --help\" for more information."
  80         if [ ! -z "${MESSAGE}" ]; then
  81                 echo -e "${MESSAGE}"
  82                 exit 1
  83         else
  84                 exit 0
  85         fi
  86 }
  87
  88 Help ()
  89 {
  90         Header
  91         echo
  92         echo "Options:"
  93         echo "  -c, --cow: specifies the copy on write directory (default: /cow)."
  94         echo "  -d, --device: specifies the output snapshot device (default: none)."
  95         echo "  -o, --output: specifies the output image file (default: $type dependent)."
  96     echo "  -r, --resync-string: internally used to resync previous made snapshots."
  97         echo "  -t, --type: specifies the snapshot type between \"squashfs\", \"ext2\" or \"cpio\".gz archive (default: cpio)"
  98     echo -e "\nLook at live-snapshot(1) man page for more information."
  99         exit 0
 100 }
 101
 102 Version ()
 103 {
 104         echo "${PROGRAM}, version ${VERSION}"
 105         echo
 106         echo "Copyright (C) 2006 Marco Amadori <marco.amadori@gmail.com>"
 107         echo
 108         echo "This program is free software; you can redistribute it and/or modify"
 109         echo "it under the terms of the GNU General Public License as published by"
 110         echo "the Free Software Foundation; either version 2 of the License, or"
 111         echo "(at your option) any later version."
 112         echo
 113         echo "This program is distributed in the hope that it will be useful,"
 114         echo "but WITHOUT ANY WARRANTY; without even the implied warranty of"
 115         echo "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the"
 116         echo "GNU General Public License for more details."
 117         echo
 118         echo "You should have received a copy of the GNU General Public License"
 119         echo "along with this program; if not, write to the Free Software"
 120         echo "Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA"
 121         echo
 122         echo "On Debian systems, the complete text of the GNU General Public License"
 123         echo "can be found in /usr/share/common-licenses/GPL file."
 124         echo
 125         echo "Homepage: <http://live.debian.net/>"
 126         exit 0
 127 }
 128
 129 Do_snapshot ()
 130 {
 131         case "${TYPE}" in
 132                 squashfs)
 133                         echo "./tmp/exclude_list" > /tmp/exclude_list
 134                         ( cd "${COW}" && find . -name '*.wh.*' >> /tmp/exclude_list )
 135                         mksquashfs "${COW}" "${DEST}" -ef /tmp/exclude_list || exit 1
 136                         rm /tmp/exclude_list
 137                         ;;
 138                 cpio)
 139                         ( cd "${COW}" && find . -path '*.wh.*' -prune -o -print0 | cpio --quiet -o0 -H newc | gzip -9c > "${DEST}" ) || exit 1
 140                         ;;
 141                 ext2)
 142                         DU_DIM="`du -ks ${COW} | cut -f1`"
 143                         REAL_DIM="`expr ${DU_DIM} + ${DU_DIM} / 20`" # Just 5% more to be sure, need something more sophistcated here...
 144                         genext2fs --size-in-blocks=${REAL_DIM} --reserved-blocks=0 --root="${COW}" "${DEST}" || exit 1
 145                         ;;
 146                 *)
 147                         echo "Internal error."
 148                         exit 1
 149                         ;;
 150         esac
 151 }
 152
 153 Is_same_mount ()
 154 {
 155         dir1="`Base_path $1`"
 156         dir2="`Base_path $2`"
 157         if [ "${dir1}" == "${dir2}" ]; then
 158                 return 0
 159         else
 160                 return 1
 161         fi
 162 }
 163
 164 Parse_args ()
 165 {
 166         # Parse command line
 167         ARGS="$1"
 168         ARGUMENTS="`getopt --longoptions cow:,device:,output,resync-string:,type:,help,usage,version --name=${PROGRAM} --options c:d:o:t:r:,h,u,v --shell sh -- ${ARGS}`"
 169
 170         if [ "$?" != "0" ]; then
 171                 echo "Terminating." >&2
 172                 exit 1
 173         fi
 174
 175         eval set -- "${ARGUMENTS}"
 176
 177         while true; do
 178                 case "$1" in
 179                         -c|--cow)
 180                                 SNAP_COW="$2"; shift 2 ;;
 181                         -d|--device)
 182                                 SNAP_DEV="$2"; shift 2 ;;
 183                         -o|--output)
 184                                 SNAP_OUTPUT="$2"; shift 2 ;;
 185                         -t|--type)
 186                                 SNAP_TYPE="$2"; shift 2 ;;
 187                         -r|--resync-string)
 188                                 SNAP_RSTRING="$2"; break ;;
 189                         -h|--help)
 190                                 Help; shift ;;
 191                         -u|--usage)
 192                                 Usage ; shift ;;
 193                         -v|--version)
 194                                 Version; shift ;;
 195                         --)
 196                                 shift; break ;;
 197                         *)
 198                                 echo "Internal error."; exit 1 ;;
 199                 esac
 200         done
 201 }
 202
 203 Mount_device ()
 204 {
 205         dev="$1"
 206
 207         if [ ! -d "${MOUNTP}" ]; then
 208                 mkdir -p "${MOUNTP}"
 209         fi
 210
 211         if [ -z "${dev}" ]; then
 212                 # create a temp
 213                 mount -t tmpfs -o rw tmpfs "${MOUNTP}"
 214                 if [ ! -L /home/$USERNAME/Desktop/live-snapshot ]; then
 215                         ln -s "${MOUNTP}" /home/$USERNAME/Desktop/live-snapshot
 216                 fi
 217         else
 218                 if [ -b "${dev}" ] ; then
 219                         try_mount "${dev}" "${MOUNTP}" rw
 220                 fi
 221         fi
 222 }
 223
 224 Defaults ()
 225 {
 226         MOUNTP="/mnt/live-snapshot"
 227         COW="/cow"
 228         DEV=""
 229         DEST="${MOUNTP}/live-sn.cpio.gz"
 230         TYPE="cpio"
 231         DESKTOP_LINK=/home/$USERNAME/Desktop/live-snapshot
 232
 233         if [ -n "${SNAP_RSTRING}" ]; then
 234                 COW=$(echo "${SNAP_RSTRING}" | cut -f1 -d ':')
 235                 DEV=$(echo "${SNAP_RSTRING}" | cut -f2 -d ':')
 236                 DEST=$(echo "${SNAP_RSTRING}" | cut -f3 -d ':')
 237
 238                 case "${DEST}" in
 239                         *.cpio.gz)
 240                                 TYPE="cpio" ;;
 241                         *.squashfs)
 242                                 TYPE="squashfs" ;;
 243                         "")
 244                                 TYPE="ext2" ;;
 245                         *.ext2)
 246                                 TYPE="ext2" ;;
 247                         *)
 248                                 Usage "Unregognized String" ;;
 249                 esac
 250         else
 251                 DEF_COW="/cow"
 252                 # Bad options handling
 253                 if [ -z "${SNAP_COW}" ]; then
 254                         COW="${DEF_COW}"
 255                 else
 256                         COW="${SNAP_COW}"
 257                 fi
 258
 259                 case "${SNAP_TYPE}" in
 260                         "cpio"|"squashfs"|"ext2")
 261                                 TYPE="${SNAP_TYPE}"
 262                                 ;;
 263                         "")
 264                                 TYPE="cpio" ;;
 265                         *)
 266                                 Usage "Error: unrecognized snapshot type"
 267                                 ;;
 268                 esac
 269                 #if [ -d
 270                 #if Is_same_mount
 271         fi
 272
 273         # check vars
 274         if [ ! -d "${COW}" ]; then
 275                 Usage "Error: ${COW} is not a directory"
 276         fi
 277
 278         Mount_device $DEV
 279
 280 }
 281
 282 Clean ()
 283 {
 284         if [ -n "$DEV" ]; then
 285                 umount "${MOUNTP}"
 286                 rmdir "${MOUNTP}"
 287                 rm
 288         fi
 289 }
 290
 291 Main ()
 292 {
 293         Parse_args "$@"
 294         Defaults
 295         Do_snapshot
 296         Clean
 297 }
 298
 299 Main "$@"