diff --git a/components/engine/hack/dind b/components/engine/hack/dind index f8fae6379c..1242cbffe1 100755 --- a/components/engine/hack/dind +++ b/components/engine/hack/dind @@ -33,28 +33,35 @@ if [ -d /sys/kernel/security ] && ! mountpoint -q /sys/kernel/security; then fi # Mount the cgroup hierarchies exactly as they are in the parent system. -for SUBSYS in $(cut -d: -f2 /proc/1/cgroup); do - mkdir -p "$CGROUP/$SUBSYS" - if ! mountpoint -q $CGROUP/$SUBSYS; then - mount -n -t cgroup -o "$SUBSYS" cgroup "$CGROUP/$SUBSYS" - fi +for HIER in $(cut -d: -f2 /proc/1/cgroup); do - # The two following sections address a bug which manifests itself + # The following sections address a bug which manifests itself # by a cryptic "lxc-start: no ns_cgroup option specified" when - # trying to start containers withina container. + # trying to start containers within a container. # The bug seems to appear when the cgroup hierarchies are not # mounted on the exact same directories in the host, and in the # container. + SUBSYSTEMS="${HIER%name=*}" + + # If cgroup hierarchy is named(mounted with "-o name=foo") we + # need to mount it in $CGROUP/foo to create exect same + # directoryes as on host. Else we need to mount it as is e.g. + # "subsys1,subsys2" if it has two subsystems + # Named, control-less cgroups are mounted with "-o name=foo" # (and appear as such under /proc//cgroup) but are usually # mounted on a directory named "foo" (without the "name=" prefix). # Systemd and OpenRC (and possibly others) both create such a - # cgroup. To avoid the aforementioned bug, we symlink "foo" to - # "name=foo". This shouldn't have any adverse effect. - name="${SUBSYS#name=}" - if [ "$name" != "$SUBSYS" ]; then - ln -s "$SUBSYS" "$CGROUP/$name" + # cgroup. So just mount them on directory $CGROUP/foo. + + OHIER=$HIER + HIER="${HIER#*name=}" + + mkdir -p "$CGROUP/$HIER" + + if ! mountpoint -q $CGROUP/$HIER; then + mount -n -t cgroup -o "$OHIER" cgroup "$CGROUP/$HIER" fi # Likewise, on at least one system, it has been reported that @@ -62,8 +69,25 @@ for SUBSYS in $(cut -d: -f2 /proc/1/cgroup); do # (respectively "cpu" and "cpuacct") with "-o cpuacct,cpu" # but on a directory called "cpu,cpuacct" (note the inversion # in the order of the groups). This tries to work around it. - if [ "$SUBSYS" = 'cpuacct,cpu' ]; then - ln -s "$SUBSYS" "$CGROUP/cpu,cpuacct" + + if [ "$HIER" = 'cpuacct,cpu' ]; then + ln -s "$HIER" "$CGROUP/cpu,cpuacct" + fi + + # If hierarchy has multiple subsystems, in /proc//cgroup + # we will see ":subsys1,subsys2,subsys3,name=foo:" substring, + # we need to mount it to "$CGROUP/foo" and if there were no + # name to "$CGROUP/subsys1,subsys2,subsys3", so we must create + # symlinks for docker daemon to find these subsystems: + # ln -s $CGROUP/foo $CGROUP/subsys1 + # ln -s $CGROUP/subsys1,subsys2,subsys3 $CGROUP/subsys1 + + if [ "$SUBSYSTEMS" != "${SUBSYSTEMS//,/ }" ]; then + SUBSYSTEMS="${SUBSYSTEMS//,/ }" + for SUBSYS in $SUBSYSTEMS + do + ln -s "$CGROUP/$HIER" "$CGROUP/$SUBSYS" + done fi done