tool to get public IP of an instance
diff --git a/planetstack/tools/get_instance_ip.py b/planetstack/tools/get_instance_ip.py
new file mode 100644
index 0000000..61cc578
--- /dev/null
+++ b/planetstack/tools/get_instance_ip.py
@@ -0,0 +1,70 @@
+#! /usr/bin/python
+
+import json
+import os
+import requests
+import sys
+
+from operator import itemgetter, attrgetter
+
+REST_API="http://alpha.opencloud.us:8000/plstackapi/"
+
+NODES_API = REST_API + "nodes/"
+SLICES_API = REST_API + "slices/"
+SLIVERS_API = REST_API + "slivers/"
+
+opencloud_auth=("demo@onlab.us", "demo")
+
+def get_slice_id(slice_name):
+    r = requests.get(SLICES_API + "?name=%s" % slice_name, auth=opencloud_auth)
+    return r.json()[0]["id"]
+
+def get_node_id(host_name):
+    r = requests.get(NODES_API + "?name=%s" % host_name, auth=opencloud_auth)
+    return r.json()[0]["id"]
+
+def get_slivers(slice_id=None, node_id=None):
+    queries = []
+    if slice_id:
+        queries.append("slice=%s" % str(slice_id))
+    if node_id:
+        queries.append("node=%s" % str(node_id))
+
+    if queries:
+        query_string = "?" + "&".join(queries)
+    else:
+        query_string = ""
+
+    r = requests.get(SLIVERS_API + query_string, auth=opencloud_auth)
+    return r.json()
+
+def main():
+    global opencloud_auth
+
+    if len(sys.argv)!=5:
+        print >> sys.stderr, "syntax: get_instance_name.py <username>, <password>, <hostname> <slicename>"
+        sys.exit(-1)
+
+    username = sys.argv[1]
+    password = sys.argv[2]
+    hostname = sys.argv[3]
+    slice_name = sys.argv[4]
+
+    opencloud_auth=(username, password)
+
+    slice_id = get_slice_id(slice_name)
+    node_id = get_node_id(hostname)
+    slivers = get_slivers(slice_id, node_id)
+
+    # get (instance_name, ip) pairs for instances with names and ips
+
+    slivers = [x for x in slivers if x["instance_name"] and x["ip"]]
+    slivers = sorted(slivers, key = lambda sliver: sliver["instance_name"])
+
+    # return the last one in the list (i.e. the newest one)
+
+    print slivers[-1]["ip"]
+
+if __name__ == "__main__":
+    main()
+