Use official docker/dind image

builder/rootfs/Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.3
+FROM docker:1.8-dind
 
 # install common packages
 RUN apk add --no-cache curl bash sudo
@@ -24,13 +24,6 @@ RUN apk add --no-cache \
     util-linux \
     xz
 
-# the docker package in alpine disables aufs and devicemapper
-ENV DOCKER_BUCKET get.docker.com
-ENV DOCKER_VERSION 1.8.3
-ENV DOCKER_SHA256 f024bc65c45a3778cf07213d26016075e8172de8f6e4b5702bedde06c241650f
-RUN curl -sSL "https://${DOCKER_BUCKET}/builds/Linux/x86_64/docker-$DOCKER_VERSION" -o /usr/bin/docker \
-	&& echo "${DOCKER_SHA256} /usr/bin/docker" | sha256sum -c - \
-	&& chmod +x /usr/bin/docker
 
 # configure ssh server
 RUN mkdir -p /var/run/sshd && rm -rf /etc/ssh/ssh_host*

builder/rootfs/bin/entry

@@ -7,121 +7,4 @@ if [[ -f /etc/environment_proxy ]]; then
 	export http_proxy https_proxy all_proxy no_proxy
 fi
 
-# START jpetazzo/dind wrapper
-
-# DinD: a wrapper script which allows docker to be run inside a docker container.
-# Original version by Jerome Petazzoni <[email protected]>
-# See the blog post: https://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
-
-# as of docker 1.8, cgroups will be mounted in the container
-if ! mountpoint -q /sys/fs/cgroup; then
-
-	# 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
-
-	# Mount the cgroup hierarchies exactly as they are in the parent system.
-	for HIER in $(cut -d: -f2 /proc/1/cgroup); do
-
-		# The following sections address a bug which manifests itself
-		# by a cryptic "lxc-start: no ns_cgroup option specified" when
-		# trying to start containers within a container.
-		# The bug seems to appear when the cgroup hierarchies are not
-		# mounted on the exact same directories in the host, and in the
-		# container.
-
-		SUBSYSTEMS="${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/<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. 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
-		# 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 [ "$HIER" = 'cpuacct,cpu' ]; then
-			ln -s "$HIER" "$CGROUP/cpu,cpuacct"
-		fi
-
-		# If hierarchy has multiple subsystems, in /proc/<pid>/cgroup
-		# we will see ":subsys1,subsys2,subsys3,name=foo:" substring,
-		# we need to mount it to "$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
-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
-
-# 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 (conditionally)
-if ! mountpoint -q /tmp; then
-	mount -t tmpfs none /tmp
-fi
-
-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?'
-# END jpetazzo/dind wrapper
+/usr/local/bin/dind $@

builder/rootfs/etc/confd/templates/builder

@@ -89,7 +89,7 @@ fi
 # and write out a Dockerfile to use that slug
 if [ ! -f Dockerfile ]; then
     BUILD_OPTS=()
-    BUILD_OPTS+='/usr/bin/docker'
+    BUILD_OPTS+='/usr/local/bin/docker'
     BUILD_OPTS+=' run -v /etc/environment_proxy:/etc/environment_proxy'
     # get application configuration
     BUILD_OPTS+=$(echo $RESPONSE | get-app-values)