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|