88 lines
3 KiB
Bash
Executable file
88 lines
3 KiB
Bash
Executable file
#!/bin/bash
|
|
set -e
|
|
|
|
# DinD: a wrapper script which allows docker to be run inside a docker container.
|
|
# Original version by Jerome Petazzoni <jerome@docker.com>
|
|
# See the blog post: http://blog.docker.com/2013/09/docker-can-now-run-within-docker/
|
|
#
|
|
# This script should be executed inside a docker container in privilieged mode
|
|
# ('docker run --privileged', introduced in docker 0.6).
|
|
|
|
# Usage: dind CMD [ARG...]
|
|
|
|
# apparmor sucks and Docker needs to know that it's in a container (c) @tianon
|
|
export container=docker
|
|
|
|
# First, make sure that cgroups are mounted correctly.
|
|
CGROUP=/cgroup
|
|
|
|
mkdir -p "$CGROUP"
|
|
|
|
if ! mountpoint -q "$CGROUP"; then
|
|
mount -n -t tmpfs -o uid=0,gid=0,mode=0755 cgroup $CGROUP || {
|
|
echo >&2 'Could not make a tmpfs mount. Did you use --privileged?'
|
|
exit 1
|
|
}
|
|
fi
|
|
|
|
if [ -d /sys/kernel/security ] && ! mountpoint -q /sys/kernel/security; then
|
|
mount -t securityfs none /sys/kernel/security || {
|
|
echo >&2 'Could not mount /sys/kernel/security.'
|
|
echo >&2 'AppArmor detection and -privileged mode might break.'
|
|
}
|
|
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/$SUBSYS"
|
|
fi
|
|
|
|
# The two following sections address a bug which manifests itself
|
|
# by a cryptic "lxc-start: no ns_cgroup option specified" when
|
|
# trying to start containers withina container.
|
|
# The bug seems to appear when the cgroup hierarchies are not
|
|
# mounted on the exact same directories in the host, and in the
|
|
# container.
|
|
|
|
# Named, control-less cgroups are mounted with "-o name=foo"
|
|
# (and appear as such under /proc/<pid>/cgroup) but are usually
|
|
# mounted on a directory named "foo" (without the "name=" prefix).
|
|
# Systemd and OpenRC (and possibly others) both create such a
|
|
# cgroup. To avoid the aforementioned bug, we symlink "foo" to
|
|
# "name=foo". This shouldn't have any adverse effect.
|
|
name="${SUBSYS#name=}"
|
|
if [ "$name" != "$SUBSYS" ]; then
|
|
ln -s "$SUBSYS" "$CGROUP/$name"
|
|
fi
|
|
|
|
# Likewise, on at least one system, it has been reported that
|
|
# systemd would mount the CPU and CPU accounting controllers
|
|
# (respectively "cpu" and "cpuacct") with "-o cpuacct,cpu"
|
|
# but on a directory called "cpu,cpuacct" (note the inversion
|
|
# in the order of the groups). This tries to work around it.
|
|
if [ "$SUBSYS" = 'cpuacct,cpu' ]; then
|
|
ln -s "$SUBSYS" "$CGROUP/cpu,cpuacct"
|
|
fi
|
|
done
|
|
|
|
# Note: as I write those lines, the LXC userland tools cannot setup
|
|
# a "sub-container" properly if the "devices" cgroup is not in its
|
|
# own hierarchy. Let's detect this and issue a warning.
|
|
if ! grep -q :devices: /proc/1/cgroup; then
|
|
echo >&2 'WARNING: the "devices" cgroup should be in its own hierarchy.'
|
|
fi
|
|
if ! grep -qw devices /proc/1/cgroup; then
|
|
echo >&2 'WARNING: it looks like the "devices" cgroup is not mounted.'
|
|
fi
|
|
|
|
# Mount /tmp
|
|
mount -t tmpfs none /tmp
|
|
|
|
if [ $# -gt 0 ]; then
|
|
exec "$@"
|
|
fi
|
|
|
|
echo >&2 'ERROR: No command specified.'
|
|
echo >&2 'You probably want to run hack/make.sh, or maybe a shell?'
|