link docker_registry to extra space

Change-Id: Ib7fb2ce013d301ec741584d1780fd2b5d6d396fe
diff --git a/scripts/cord-in-a-box.sh b/scripts/cord-in-a-box.sh
index a5a15a2..82dffac 100755
--- a/scripts/cord-in-a-box.sh
+++ b/scripts/cord-in-a-box.sh
@@ -111,8 +111,10 @@
 
     sudo mkdir -p /var/extra/libvirt_images
     sudo mkdir -p /var/extra/docker
+    sudo mkdir -p /var/extra/docker-registry
     [ ! -e /var/lib/libvirt/images ] && sudo ln -s /var/extra/libvirt_images /var/lib/libvirt/images
     [ ! -e /var/lib/docker ] && sudo ln -s /var/extra/docker /var/lib/docker
+    [ ! -e /docker-registry ] && sudo ln -s /var/extra/docker-registry /docker-registry
 
     cd $CORDDIR/build
     SRC="#- 'on_cloudlab=True'"