Created a tool to delete metrics

- Provided the delete metrics tool
 - Provided instructions for tool in devStackGSG.rst

Change-Id: I7921687c2ebde4a90a1a101c39d1f1561b90b5d9

doc/source/devstackGSG.rst

@@ -141,6 +141,18 @@ To deploy with gnocchi using DevStack, add the following to you local.conf:
       GNOCCHI_USE_KEYSTONE=True
       COLLECTD_GNOCCHI_ENABLED=True
 
+Gnocchi Tools
+~~~~~~~~~~~~
+
+ * delete_metrics
+   A delete metrics tool is available to delete all metrics. This tool has to
+   be used manually. See :doc:`<tools/delete_metrics.sh>`
+   To delete all of the pre-existing metrics, just run the following command:
+
+     ::
+
+       $ . tools/delete_metrics.sh
+
 Aodh
 ----
 

tools/delete_metrics.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+echo "All gnocchi plugin metrics are being deleted. This may take a few minutes.."
+for metric in `openstack metric metric list | awk 'NR > 2 {print $2}'`;
+do
+    openstack metric metric delete $metric
+done
+echo "All metrics created by the collectd-gnocchi-plugin have been deleted"