Add unstack.sh

unstack.sh is a simple clean-up script to kill known running
OpenStack processes:
* quit devstack's screen session
* stop swift daemons
* stop apache
* remove volumes

Change-Id: I41b33817c4436e644c336e4e0673144ac0844c26

unstack.sh

@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+#
+# Stops that which is started by ``stack.sh`` (mostly)
+# mysql and rabbit are left running as OpenStack code refreshes
+# do not require them to be restarted.
+#
+# Stop all processes by setting UNSTACK_ALL or specifying ``--all``
+# on the command line
+
+# Keep track of the current devstack directory.
+TOP_DIR=$(cd $(dirname "$0") && pwd)
+
+# Import common functions
+source $TOP_DIR/functions
+
+# Load local configuration
+source $TOP_DIR/stackrc
+
+# Determine what system we are running on.  This provides ``os_VENDOR``,
+# ``os_RELEASE``, ``os_UPDATE``, ``os_PACKAGE``, ``os_CODENAME``
+GetOSVersion
+
+if [[ "$1" == "--all" ]]; then
+    UNSTACK_ALL=${UNSTACK_ALL:-1}
+fi
+
+# Shut down devstack's screen to get the bulk of OpenStack services in one shot
+SESSION=$(screen -ls | grep "[0-9].stack" | awk '{ print $1 }')
+if [[ -n "$SESSION" ]]; then
+    screen -X -S $SESSION quit
+fi
+
+# Swift runs daemons
+if is_service_enabled swift; then
+    swift-init all stop
+fi
+
+# Apache has the WSGI processes
+if is_service_enabled horizon; then
+    stop_service apache2
+fi
+
+# Get the iSCSI volumes
+if is_service_enabled n-vol; then
+    TARGETS=$(sudo tgtadm --op show --mode target)
+    if [[ -n "$TARGETS" ]]; then
+        # FIXME(dtroyer): this could very well require more here to
+        #                 clean up left-over volumes
+        echo "iSCSI target cleanup needed:"
+        echo "$TARGETS"
+    fi
+    sudo stop tgt
+fi
+
+if [[ -n "$UNSTACK_ALL" ]]; then
+    # Stop MySQL server
+    if is_service_enabled mysql; then
+        stop_service mysql
+    fi
+fi