Install undocker & create a bocker image from busybox; Move unshare to /usr/bin

Vagrantfile

@@ -1,16 +1,29 @@
 $script = <<SCRIPT
-yum install -y autoconf automake btrfs-progs gettext-devel git libtool
+(
+rpm -i https://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-5.noarch.rpm
+yum install -y -q autoconf automake btrfs-progs docker gettext-devel git libtool python-pip
+
 fallocate -l 10G ~/btrfs.img
 mkdir /var/bocker
 mkfs.btrfs ~/btrfs.img
 mount -o loop ~/btrfs.img /var/bocker
+
+pip install git+https://github.com/larsks/undocker
+systemctl start docker.service
+docker pull busybox
+docker save busybox | undocker -o base-image
+rm -rf /vagrant/base-image
+mv base-image /vagrant || true
+
 git clone https://github.com/karelzak/util-linux.git
 cd util-linux
 git checkout tags/v2.25.2
 ./autogen.sh
 ./configure --without-ncurses --without-python
 make
+mv unshare /usr/bin/unshare
 cd ..
+) 2>&1
 SCRIPT
 
 Vagrant.configure(2) do |config|

bocker

@@ -3,7 +3,7 @@ set -o errexit -o nounset -o pipefail; shopt -s nullglob
 
 btrfs_path='/var/bocker';
 basename=$(which basename);	btrfs=$(which btrfs);	cat=$(which cat);
-mount=$(which mount);		umount=$(which umount);	chroot=$(which chroot)
+unshare=$(which unshare);	umount=$(which umount);	chroot=$(which chroot)
 
 function CHECK_VOLUME() {
 if $btrfs subvolume list "$btrfs_path" | grep -qw "$1"; then
@@ -50,8 +50,8 @@ CHECK_VOLUME "$1"
 uuid="ps_$(uuidgen)"
 $btrfs subvolume snapshot "$btrfs_path/$1" "$btrfs_path/$uuid" > /dev/null
 echo "$2" > "$btrfs_path/$uuid/$uuid.cmd"
-./util-linux/unshare -fp --mount-proc "$chroot" "$btrfs_path/$uuid" \
-	/bin/bash -c "/bin/mount -t proc proc /proc && /bin/$2" \
+"$unshare" -fp --mount-proc "$chroot" "$btrfs_path/$uuid" \
+	/bin/sh -c "/bin/mount -t proc proc /proc && /bin/$2" \
 	2>&1 | tee "$btrfs_path/$uuid/$uuid.log"
 $umount "$btrfs_path/$uuid/proc"
 }