commit 7ef0141356454503ab81460290b5dffa32c1f441
Author: David Ward <david.ward@ll.mit.edu>
Date: Fri May 4 00:50:15 2012 +0200
refresh lxc-ls
Add an '--active' option that lists active containers by searching
cgroups. (Otherwise, the directories in /var/lib/lxc are listed.)
Modify the cgroup search to only use hierarchies that contain one
or more subsystems. When searching, if a hierarchy contains the
'ns' subsystem, do not append '/lxc' to the parent cgroup.
Add a '--help' option that prints the command syntax.
Print error messages and help information to stderr.
Update the documentation.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
diff --git a/doc/lxc-ls.sgml.in b/doc/lxc-ls.sgml.in
index 3ffd4f8..d33e9b3 100644
--- a/doc/lxc-ls.sgml.in
+++ b/doc/lxc-ls.sgml.in
@@ -48,7 +48,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
<refsynopsisdiv>
<cmdsynopsis>
- <command>lxc-ls <optional>ls option</optional>
+ <command>lxc-ls <optional>--active</optional> <optional>ls option</optional>
</command>
</cmdsynopsis>
</refsynopsisdiv>
@@ -67,6 +67,17 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
<varlistentry>
<term>
+ <option><optional>--active</optional></option>
+ </term>
+ <listitem>
+ <para>
+ List active containers.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>
<option><optional>ls options</optional></option>
</term>
<listitem>
@@ -94,10 +105,10 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
</varlistentry>
<varlistentry>
- <term>lxc-ls -1</term>
+ <term>lxc-ls --active -1</term>
<listitem>
<para>
- list all the containers and display the list in one column.
+ list active containers and display the list in one column.
</para>
</listitem>
</varlistentry>
diff --git a/src/lxc/lxc-ls.in b/src/lxc/lxc-ls.in
index a1ad642..11a3b45 100644
--- a/src/lxc/lxc-ls.in
+++ b/src/lxc/lxc-ls.in
@@ -1,43 +1,100 @@
#!/bin/bash
-localstatedir=@LOCALSTATEDIR@
-lxcpath=@LXCPATH@
+#
+# lxc: linux Container library
-if [ ! -r $lxcpath ]; then
- exit 0
-fi
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# Lesser General Public License for more details.
+
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+localstatedir=@LOCALSTATEDIR@
+lxc_path=@LXCPATH@
-function get_cgroup()
+usage()
{
- local mount_string
- mount_string=$(mount -t cgroup |grep -E -e '^lxc ')
- if test -n "$mount_string"; then
- mount_point=$(echo $mount_string |cut -d' ' -f3)
- return
- fi
- mount_string=`grep -m1 -E '^[^ \t]+[ \t]+[^ \t]+[ \t]+cgroup' /proc/self/mounts`;
- if test -z "$mount_string"; then
- echo "failed to find mounted cgroup"
- exit 1
- fi
- mount_point=`echo "$mount_string" |cut -d' ' -f2`;
+ echo "usage: $(basename $0) [--active] [--] [LS_OPTIONS...]" >&2
}
-ls "$@" $lxcpath
+help() {
+ usage
+ echo >&2
+ echo "List containers existing on the system." >&2
+ echo >&2
+ echo " --active list active containers" >&2
+ echo " LS_OPTIONS ls command options (see \`ls --help')" >&2
+}
+
+get_parent_cgroup()
+{
+ local hierarchies hierarchy fields subsystems init_cgroup mountpoint
+
+ parent_cgroup=""
+
+ # Obtain a list of hierarchies that contain one or more subsystems
+ hierarchies=$(tail -n +2 /proc/cgroups | cut -f 2)
-active=$(netstat -xl 2>/dev/null | grep $lxcpath | \
- sed -e 's#.*'"$lxcpath/"'\(.*\)/command#\1#');
+ # Iterate through the list until a suitable hierarchy is found
+ for hierarchy in $hierarchies; do
+ # Obtain information about the init process in the hierarchy
+ fields=$(grep -E "^$hierarchy:" /proc/1/cgroup | head -n 1)
+ if [ -z "$fields" ]; then continue; fi
+ fields=${fields#*:}
-if test -n "$active"; then
- get_cgroup
- if test -n "$mount_point"; then
- # get cgroup for init
- init_cgroup=`cat /proc/1/cgroup | awk -F: '{ print $3 }' | head -1`
- if [ ! -d $mount_point/$init_cgroup/lxc ]; then
- cd $mount_point/$init_cgroup
+ # Get a comma-separated list of the hierarchy's subsystems
+ subsystems=${fields%:*}
+
+ # Get the cgroup of the init process in the hierarchy
+ init_cgroup=${fields#*:}
+
+ # Get the filesystem mountpoint of the hierarchy
+ mountpoint=$(grep -E "^cgroup [^ ]+ [^ ]+ ([^ ]+,)?$subsystems(,[^ ]+)? " /proc/self/mounts | cut -d ' ' -f 2)
+ if [ -z "$mountpoint" ]; then continue; fi
+
+ # Return the absolute path to the containers' parent cgroup
+ # (do not append '/lxc' if the hierarchy contains the 'ns' subsystem)
+ if [[ ",$subsystems," == *,ns,* ]]; then
+ parent_cgroup="${mountpoint}${init_cgroup%/}"
else
- cd $mount_point/$init_cgroup/lxc
+ parent_cgroup="${mountpoint}${init_cgroup%/}/lxc"
fi
- ls "$@" -d $active
- fi
+ break
+ done
+}
+
+directory="$lxc_path"
+
+for i in "$@"; do
+ case $i in
+ --help)
+ help; exit 1;;
+ --active)
+ get_parent_cgroup; directory="$parent_cgroup"; shift;;
+ --)
+ shift; break;;
+ *)
+ break;;
+ esac
+done
+
+containers=""
+if [ ! -z "$directory" ]; then
+ containers=$(find $directory -mindepth 1 -maxdepth 1 -type d -printf "%f\n" 2>/dev/null)
fi
+
+if [ -z "$containers" ]; then
+ echo "$(basename $0): no containers found" >&2
+ exit 1
+fi
+
+cd "$directory"
+ls -d $@ $containers