Add one-get-instances scripts

one-get-instances

@@ -0,0 +1,18 @@
+#!/bin/sh
+#
+# This script extract VM IDs and filter them if a pattern is provided as first
+# argument.
+
+set -e
+
+# Extract instances from ONE.
+instances=$(onevm list --csv | tail -n +2)
+
+# Filter them is a pattern has been provided.
+if [ "$1" != "" ]; then
+	filtered_instances="$(echo "$instances" | grep -E "$1")"
+	instances="$filtered_instances"
+fi
+
+# Outputs instance IDs.
+echo "$instances" | cut -d ',' -f 1 -