labs: make use of snapshot functionality

This changeset pushes some of the code from virtualbox.install_node
to the configuration files.

In doing so, the patch demonstrates how additional snapshots can be
configured just by editing config/scripts.*.

Implements: blueprint openstack-training-labs
Change-Id: I1f5f6d5aa3842da8fa94bd1a10a753bb80db023b

labs/config/scripts.compute

@@ -1 +1,4 @@
 # Scripts for compute node
+scripts shutdown.sh
+boot
+snapshot "pre-installed"

labs/config/scripts.controller

@@ -2,3 +2,6 @@
 scripts apt_install_mysql.sh
 scripts setup_keystone.sh
 scripts setup_glance.sh
+scripts shutdown.sh
+boot
+snapshot "pre-installed"

labs/config/scripts.network

@@ -1 +1,4 @@
 # Scripts for network node
+scripts shutdown.sh
+boot
+snapshot "pre-installed"

labs/config/scripts.nodeinit_osbash

@@ -3,3 +3,5 @@ scripts etc_hosts.sh
 osbash enable_vagrant_ssh_keys.sh
 #osbash wait_debug.sh
 scripts shutdown.sh
+boot
+snapshot "Network configured."

labs/lib/osbash/virtualbox.install_node

@@ -69,14 +69,9 @@ function vm_build_node {
     autostart_and_rename osbash init_xxx_node.sh "init_${NODE_NAME}_node.sh"
     autostart_from_config scripts.nodeinit_osbash
 
-    _vbox_boot_with_autostart "$NODE_NAME" "$VM_SSH_PORT"
-    vm_snapshot "$NODE_NAME" "network_configured"
     #- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     autostart_reset
     autostart_from_config "scripts.$NODE_NAME"
-    autostart scripts shutdown.sh
-    _vbox_boot_with_autostart "$NODE_NAME" "$VM_SSH_PORT"
-    vm_snapshot "$NODE_NAME" "pre-installed"
     #- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     ${WBATCH:-:} wbatch_end_file