bin/casper-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 ${0}`"
  29 VERSION=0.0.1
  30
  31
  32 # Source casper conf
  33 if [ -e /etc/casper.conf ]; then
  34         . /etc/casper.conf
  35 else
  36         USERNAME=$(cat /etc/passwd | grep "999" | cut -f1 -d ':')
  37         HOSTNAME=$(hostname)
  38         BUILD_SYSTEM="Debian"
  39 fi
  40
  41 export USERNAME USERFULLNAME HOSTNAME BUILD_SYSTEM
  42
  43 # Source helper functions
  44 helpers="/usr/share/initramfs-tools/scripts/casper-helpers"
  45 if [ -e "${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 # Some defaults:
  57 MOUNTP="/mnt/casper-snapshot"
  58 COW="/cow"
  59 DEV=""
  60 DEST="${MOUNTP}/casper-sn.cpio.gz"
  61 TYPE="cpio"
  62 DESKTOP_LINK=/home/$USERNAME/Desktop/casper-snapshot
  63
  64 Header ()
  65 {
  66         echo "${PROGRAM} - utility to do Debian Live snapshots"
  67         echo
  68         echo "Usage: ${PROGRAM} [-c|--cow DIRECTORY] [-d|--device DEVICE] [-o|--output FILE] [-t|--type TYPE]"
  69         echo "Usage: ${PROGRAM} [-r|--resync-string STRING]"
  70         echo "Usage: ${PROGRAM} [-h|--help]"
  71         echo "Usage: ${PROGRAM} [-u|--usage]"
  72         echo "Usage: ${PROGRAM} [-v|--version]"
  73 }
  74
  75 Usage ()
  76 {
  77         MESSAGE=${1}
  78         Header
  79         echo
  80         echo "Try \"${PROGRAM} --help\" for more information."
  81         if [ ! -z "${MESSAGE}" ]; then
  82                 echo -e "${MESSAGE}"
  83                 exit 1
  84         else
  85                 exit 0
  86         fi
  87 }
  88
  89 Help ()
  90 {
  91         Header
  92         echo
  93         echo "Options:"
  94         echo "  -c, --cow: specifies the copy on write directory (default: /cow)."
  95         echo "  -d, --destination: specifies the output snapshot directory (default: /home/\$USERNAME/Desktop/casper-snapshot)."
  96         echo "  -o, --output: specifies the output image file (default: $type dependent)."
  97     echo "  -r, --resync-string: internally used to resync previous made snapshots."
  98         echo "  -t,--type: specifies the snapshot type between \'squashfs\', \'ext2\' or \'cpio\'.gz archive (default: cpio)"
  99     echo -e "\nLook at casper-snapshot(1) man page for more information."
 100         exit 0
 101 }
 102
 103 Version ()
 104 {
 105         echo "${PROGRAM}, version ${VERSION}"
 106         echo
 107         echo "Copyright (C) 2006 Marco Amadori <marco.amadori@gmail.com>"
 108         echo
 109         echo "This program is free software; you can redistribute it and/or modify"
 110         echo "it under the terms of the GNU General Public License as published by"
 111         echo "the Free Software Foundation; either version 2 of the License, or"
 112         echo "(at your option) any later version."
 113         echo
 114         echo "This program is distributed in the hope that it will be useful,"
 115         echo "but WITHOUT ANY WARRANTY; without even the implied warranty of"
 116         echo "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the"
 117         echo "GNU General Public License for more details."
 118         echo
 119         echo "You should have received a copy of the GNU General Public License"
 120         echo "along with this program; if not, write to the Free Software"
 121         echo "Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA"
 122         echo
 123         echo "On Debian systems, the complete text of the GNU General Public License"
 124         echo "can be found in /usr/share/common-licenses/GPL file."
 125         echo
 126         echo "Homepage: <http://live.debian.net/>"
 127         exit 0
 128 }
 129
 130 Do_snapshot ()
 131 {
 132         case "${TYPE}" in
 133                 squashfs)
 134                         echo "./tmp/exclude_list" > /tmp/exclude_list
 135                         ( cd "${COW}" && find . -name '*.wh.*' >> /tmp/exclude_list )
 136                         mksquashfs "${COW}" "${DEST}" -ef /tmp/exclude_list || exit 1
 137                         rm /tmp/exclude_list
 138                         ;;
 139                 cpio)
 140                         ( cd "${COW}" && find . -path '*.wh.*' -prune -o -print0 | cpio --quiet -o0 -H newc | gzip -9c > "${DEST}" ) || exit 1
 141                         ;;
 142                 ext2)
 143                         DU_DIM="`du -ks ${COW} | cut -f1`"
 144                         REAL_DIM="`expr ${DU_DIM} + ${DU_DIM} / 20`" # Just 5% more to be sure, need something more sophistcated here...
 145                         genext2fs --size-in-blocks=${REAL_DIM} --reserved-blocks=0 --root="${COW}" "${DEST}" || exit 1
 146                         ;;
 147                 *)
 148                         echo "Internal error."
 149                         exit 1
 150                         ;;
 151         esac
 152 }
 153
 154 Is_same_mount ()
 155 {
 156         dir1="`Base_path ${1}`"
 157         dir2="`Base_path ${2}`"
 158         if [ "${dir1}" == "${dir2}" ]; then
 159                 return 0
 160         else
 161                 return 1
 162         fi
 163 }
 164
 165 Parse_args ()
 166 {
 167         # Parse command line
 168         ARGS="${1}"
 169         ARGUMENTS="`getopt --longoptions cow:,destination:,output:,type:,help,usage,version --name=${PROGRAM} --options c:d:o:t:,h,u,v --shell sh -- ${ARGS}`"
 170
 171         if [ "${?}" != "0" ]; then
 172                 echo "Terminating." >&2
 173                 exit 1
 174         fi
 175
 176         eval set -- "${ARGUMENTS}"
 177
 178         while true; do
 179                 case "${1}" in
 180                         -c|--cow)
 181                                 SNAP_COW="${2}"; shift 2 ;;
 182                         -d|--device)
 183                                 SNAP_DEV="${2}"; shift 2 ;;
 184                         -o|--output)
 185                                 SNAP_OUTPUT="${2}"; shift 2 ;;
 186                         -t|--type)
 187                                 SNAP_TYPE="${2}"; shift 2 ;;
 188                         -r|--resync-string)
 189                                 SNAP_RSTRING="${2}"; break ;;
 190                         -h|--help)
 191                                 Help; shift ;;
 192                         -u|--usage)
 193                                 Usage ; shift ;;
 194                         -v|--version)
 195                                 Version; shift ;;
 196                         --)
 197                                 shift; break ;;
 198                         *)
 199                                 echo "Internal error."; exit 1 ;;
 200                 esac
 201         done
 202 }
 203
 204 Mount_device ()
 205 {
 206         dev="${1}"
 207
 208         if [ ! -d "${MOUNTP}" ]; then
 209                 mkdir -p "${MOUNTP}"
 210         fi
 211
 212         if [ -n "${dev}" ]; then
 213                 # create a temp
 214                 mount -t tmpfs -o rw tmpfs "${MOUNTP}"
 215                 if [ ! -L /home/$USERNAME/Desktop/casper-snapshot ]; then
 216                         ln -s "${MOUNTP}" /home/$USERNAME/Desktop/casper-snapshot
 217                 fi
 218         else
 219                 if [ -b "${dev}" ] ; then
 220                         try_mount "${dev}" "${MOUNTP}" rw
 221                 fi
 222         fi
 223 }
 224
 225 Defaults ()
 226 {
 227         if [ -n "${SNAP_RSTRING}" ]; then
 228                 COW=$(echo "${SNAP_RSTRING}" | cut -f1 -d ':')
 229                 DEV=$(echo "${SNAP_RSTRING}" | cut -f2 -d ':')
 230                 DEST=$(echo "${SNAP_RSTRING}" | cut -f3 -d ':')
 231
 232                 case "${DEST}" in
 233                         *.cpio.gz|*.cpz|*.gz)
 234                                 TYPE="cpio" ;;
 235                         *.squashfs|*.squ})
 236                                 TYPE="squashfs" ;;
 237                         "")
 238                                 TYPE="ext2" ;;
 239                         *.ext2|*.ext)
 240                                 TYPE="ext2" ;;
 241                         *)
 242                                 Usage "Unregognized String" ;;
 243                 esac
 244         else
 245                 DEF_COW="/cow"
 246                 # Bad options handling
 247                 if [ -z "${SNAP_COW}" ]; then
 248                         COW="${DEF_COW}"
 249                 else
 250                         COW="${SNAP_COW}"
 251                 fi
 252
 253                 case "${SNAP_TYPE}" in
 254                         "cpio"|"squashfs"|"ext2")
 255                                 TYPE="${SNAP_TYPE}"
 256                                 ;;
 257                         "")
 258                                 TYPE="cpio" ;;
 259                         *)
 260                                 Usage "Error: unrecognized snapshot type"
 261                                 ;;
 262                 esac
 263                 #if [ -d
 264                 #if Is_same_mount
 265         fi
 266
 267         Mount_device $DEV
 268         DEST="${MOUNTP}/${DEST}"
 269
 270         # check vars
 271         if [ ! -d "${COW}" ]; then
 272                 Usage "Error: ${COW} is not a directory"
 273         fi
 274 }
 275
 276 Clean ()
 277 {
 278         if [ -n "$DEV" ]; then
 279                 umount "${MOUNTP}"
 280                 rmdir "${MOUNTP}"
 281                 rm
 282         fi
 283 }
 284
 285 Main ()
 286 {
 287         Parse_args "${@}"
 288         Defaults
 289         Do_snapshot
 290         Clean
 291 }
 292
 293 Main "${@}"