[lxc-devel] [PATCH 2/2] Set kmsg to 0 by default

[Stéphane Graber]

It's now been proven over and over again that the symlink from /dev/kmsg
to /dev/console is harmful for everything but upstart systems. As Ubuntu
is now switching over to systemd too, lets switch the default.

Upstart users wishing to see boot messages can always set lxc.kmsg = 1
manually in their config (so long as they don't expect to then
dist-upgrade the container to systemd succesfuly).

Signed-off-by: Stéphane Graber <stgraber at ubuntu.com>
---
 config/templates/archlinux.common.conf.in |  3 ---
 doc/lxc.container.conf.sgml.in            |  4 ++--
 src/lxc/conf.c                            |  2 +-
 templates/lxc-debian.in                   |  6 ------
 templates/lxc-fedora.in                   | 14 --------------
 templates/lxc-oracle.in                   |  5 -----
 templates/lxc-sshd.in                     |  1 -
 7 files changed, 3 insertions(+), 32 deletions(-)

diff --git a/config/templates/archlinux.common.conf.in b/config/templates/archlinux.common.conf.in
index 8dea976..693f2f4 100644
--- a/config/templates/archlinux.common.conf.in
+++ b/config/templates/archlinux.common.conf.in
@@ -4,9 +4,6 @@ lxc.include = @LXCTEMPLATECONFIG@/common.conf
 # Allow for 6 tty devices by default
 lxc.tty = 6
 
-# Disable kmsg
-lxc.kmsg = 0
-
 # Set the halt/stop signals
 lxc.haltsignal=SIGRTMIN+4
 lxc.stopsignal=SIGRTMIN+14
diff --git a/doc/lxc.container.conf.sgml.in b/doc/lxc.container.conf.sgml.in
index 96d574f..a86b1e5 100644
--- a/doc/lxc.container.conf.sgml.in
+++ b/doc/lxc.container.conf.sgml.in
@@ -674,7 +674,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     <refsect2>
       <title>Enable kmsg symlink</title>
       <para>
-        Enable creating /dev/kmsg as symlink to /dev/console.  This defaults to 1.
+        Enable creating /dev/kmsg as symlink to /dev/console.  This defaults to 0.
       </para>
       <variablelist>
     <varlistentry>
@@ -683,7 +683,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
       </term>
       <listitem>
         <para>
-          Set this to 0 to disable /dev/kmsg symlinking.
+          Set this to 1 to enable /dev/kmsg symlinking.
         </para>
       </listitem>
     </varlistentry>
diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index f0b2242..10582ae 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -2523,7 +2523,7 @@ struct lxc_conf *lxc_conf_init(void)
 		free(new);
 		return NULL;
 	}
-	new->kmsg = 1;
+	new->kmsg = 0;
 	lxc_list_init(&new->cgroup);
 	lxc_list_init(&new->network);
 	lxc_list_init(&new->mount_list);
diff --git a/templates/lxc-debian.in b/templates/lxc-debian.in
index 0a3c402..8955363 100644
--- a/templates/lxc-debian.in
+++ b/templates/lxc-debian.in
@@ -188,12 +188,6 @@ configure_debian_systemd()
     path=$1
     rootfs=$2
 
-    init="$(chroot ${rootfs} dpkg-query --search /sbin/init | cut -d : -f 1)"
-    if [ "$init" = "systemd-sysv" ]; then
-       # only appropriate when systemd is PID 1
-       echo 'lxc.kmsg = 0' >> "$path/config"
-    fi
-
     # this only works if we have getty at .service to manipulate
     if [ -f ${rootfs}/lib/systemd/system/getty\@.service ]; then
        sed -e 's/^ConditionPathExists=/# ConditionPathExists=/' \
diff --git a/templates/lxc-fedora.in b/templates/lxc-fedora.in
index 36d22c5..5e7de80 100644
--- a/templates/lxc-fedora.in
+++ b/templates/lxc-fedora.in
@@ -1117,12 +1117,6 @@ lxc.include = @LXCTEMPLATECONFIG@/fedora.common.conf
 " >> $config_path/config
     fi
 
-    if [ "x$have_systemd" = "x1" ]; then
-        cat <<EOF >> $config_path/config
-lxc.kmsg = 0
-EOF
-    fi
-
     # Append things which require expansion here...
     cat <<EOF >> $config_path/config
 lxc.arch = $arch
@@ -1344,14 +1338,6 @@ if [ -z "$release" ]; then
     fi
 fi
 
-# Fedora 15 and above run systemd.We need autodev enabled to keep
-# systemd from causing problems.
-# Also, kmsg must not be mapped to prevent a 100% cpu loop
-# in systemd-journald.
-if [ $release -gt 14 ]; then
-    have_systemd="1"
-fi
-
 if [ "$(id -u)" != "0" ]; then
     echo "This script should be run as 'root'"
     exit 1
diff --git a/templates/lxc-oracle.in b/templates/lxc-oracle.in
index 8ec02da..c35ac40 100644
--- a/templates/lxc-oracle.in
+++ b/templates/lxc-oracle.in
@@ -480,11 +480,6 @@ EOF
         echo "lxc.cap.drop = setfcap setpcap" >>$cfg_dir/config
     fi
 
-    # don't create kmsg symlink as it causes journald to use 100% cpu
-    if [ $container_release_major = "7" ]; then
-        echo "lxc.kmsg = 0" >>$cfg_dir/config
-    fi
-
     echo "# Networking" >>$cfg_dir/config
     # see if the network settings were already specified
     lxc_network_type=`grep '^lxc.network.type' $cfg_dir/config | awk -F'[= \t]+' '{ print $2 }'`
diff --git a/templates/lxc-sshd.in b/templates/lxc-sshd.in
index 949c2ad..aa45c1d 100644
--- a/templates/lxc-sshd.in
+++ b/templates/lxc-sshd.in
@@ -129,7 +129,6 @@ copy_configuration()
 cat <<EOF >> $path/config
 lxc.utsname = $name
 lxc.pts = 1024
-lxc.kmsg = 0
 lxc.cap.drop = sys_module mac_admin mac_override sys_time
 
 # When using LXC with apparmor, uncomment the next line to run unconfined:
-- 
1.9.1