src/lxc/legacy/lxc-ls.in

   1 #!/bin/sh
   2
   3 #
   4 # lxc: linux Container library
   5
   6 # This library is free software; you can redistribute it and/or
   7 # modify it under the terms of the GNU Lesser General Public
   8 # License as published by the Free Software Foundation; either
   9 # version 2.1 of the License, or (at your option) any later version.
  10
  11 # This library is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 # Lesser General Public License for more details.
  15
  16 # You should have received a copy of the GNU Lesser General Public
  17 # License along with this library; if not, write to the Free Software
  18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19
  20 . @DATADIR@/lxc/lxc.functions
  21
  22 usage()
  23 {
  24         echo "usage: $(basename $0) [--active] [--] [LS_OPTIONS...]" >&2
  25 }
  26
  27 help() {
  28         usage
  29         echo >&2
  30         echo "List containers existing on the system." >&2
  31         echo >&2
  32         echo "  --active     list active containers" >&2
  33         echo "  LS_OPTIONS   ls command options (see \`ls --help')" >&2
  34 }
  35
  36 get_parent_cgroup()
  37 {
  38         parent_cgroup=""
  39
  40         # Obtain a list of hierarchies that contain one or more subsystems
  41         hierarchies=$(tail -n +2 /proc/cgroups | cut -f 2)
  42
  43         # Iterate through the list until a suitable hierarchy is found
  44         for hierarchy in $hierarchies; do
  45                 # Obtain information about the init process in the hierarchy
  46                 fields=$(grep -E "^$hierarchy:" /proc/1/cgroup | head -n 1)
  47                 if [ -z "$fields" ]; then continue; fi
  48                 fields=${fields#*:}
  49
  50                 # Get a comma-separated list of the hierarchy's subsystems
  51                 subsystems=${fields%:*}
  52
  53                 # Get the cgroup of the init process in the hierarchy
  54                 init_cgroup=${fields#*:}
  55
  56                 # Get the filesystem mountpoint of the hierarchy
  57                 mountpoint=$(awk -v subsysregex="(^|,)$subsystems(,|\$)" \
  58                         '$3 == "cgroup" && $4 ~ subsysregex {print $2}' /proc/self/mounts)
  59                 if [ -z "$mountpoint" ]; then continue; fi
  60
  61                 # Return the absolute path to the containers' parent cgroup
  62                 # (do not append '/lxc' if the hierarchy contains the 'ns' subsystem)
  63                 case ",$subsystems," in
  64                         *,ns,*) parent_cgroup="${mountpoint}${init_cgroup%/}";;
  65                         *) parent_cgroup="${mountpoint}${init_cgroup%/}/lxc";;
  66                 esac
  67                 break
  68         done
  69 }
  70
  71 directory=$(readlink -f "$lxc_path")
  72
  73 for i in "$@"; do
  74         case $i in
  75                 --help)
  76                         help; exit;;
  77                 --active)
  78                         get_parent_cgroup; directory="$parent_cgroup"; shift;;
  79                 --)
  80                         shift; break;;
  81                 *)
  82                         break;;
  83         esac
  84 done
  85
  86 containers=""
  87 if [ ! -z "$directory" ]; then
  88         if [ x"$parent_cgroup" = x ]; then
  89                 containers=$(find $directory -mindepth 2 -maxdepth 2 -name config -type f |awk -F "/" '{print $(NF-1)}')
  90         else
  91                 containers=$(find $directory -mindepth 1 -maxdepth 1 -type d 2>/dev/null | sed 's:.*/::')
  92         fi
  93         if [ x"$containers" = x ]; then
  94                 exit 0
  95         fi
  96 fi
  97
  98 cd "$directory"
  99 ls -d $@ -- $containers