Added a tool to get the Network Graph elements.

Usage:
web/get_network_graph.py <elements_name> : Print network elements with name of <elements_name>
    Valid element names:
        all              : Print all network elements
        switches         : Print all switches and ports
        links            : Print all links

Change-Id: I33222b4583e64c676e1860c3467bcd3c73fcb94a
diff --git a/web/get_network_graph.py b/web/get_network_graph.py
new file mode 100755
index 0000000..ed3292b
--- /dev/null
+++ b/web/get_network_graph.py
@@ -0,0 +1,114 @@
+#! /usr/bin/env python
+# -*- Mode: python; py-indent-offset: 4; tab-width: 8; indent-tabs-mode: t; -*-
+
+#
+# Get Network Graph Elements
+#
+
+import pprint
+import os
+import sys
+import subprocess
+import json
+import argparse
+import io
+import time
+
+from flask import Flask, json, Response, render_template, make_response, request
+
+## Global Var ##
+ControllerIP="127.0.0.1"
+ControllerPort=8080
+
+DEBUG=0
+pp = pprint.PrettyPrinter(indent=4)
+
+app = Flask(__name__)
+
+## Worker Functions ##
+def log_error(txt):
+  print '%s' % (txt)
+
+def debug(txt):
+  if DEBUG:
+    print '%s' % (txt)
+
+# @app.route("/wm/onos/ng/links/json ")
+# @app.route("/wm/onos/ng/switches/json ")
+# Sample output:
+
+def print_parsed_result(parsedResult):
+  print '%s' % (parsedResult),
+
+def get_network_switches():
+  try:
+    command = "curl -s \"http://%s:%s/wm/onos/ng/switches/json\"" % (ControllerIP, ControllerPort)
+    debug("get_network_switches %s" % command)
+
+    result = os.popen(command).read()
+    debug("result %s" % result)
+    if len(result) == 0:
+      print "No Switches found"
+      return;
+
+    # parsedResult = result
+    # parsedResult = json.loads(result)
+    parsedResult = json.dumps(json.loads(result), indent=4)
+    debug("parsed %s" % parsedResult)
+  except:
+    log_error("Controller IF has issue")
+    exit(1)
+
+  print_parsed_result(parsedResult)
+
+def get_network_links():
+  try:
+    command = "curl -s \"http://%s:%s/wm/onos/ng/links/json\"" % (ControllerIP, ControllerPort)
+    debug("get_network_links %s" % command)
+
+    result = os.popen(command).read()
+    debug("result %s" % result)
+    if len(result) == 0:
+      print "No Links found"
+      return;
+
+    # parsedResult = result
+    # parsedResult = json.loads(result)
+    parsedResult = json.dumps(json.loads(result), indent=4)
+    debug("parsed %s" % parsedResult)
+  except:
+    log_error("Controller IF has issue")
+    exit(1)
+
+  print_parsed_result(parsedResult)
+
+
+if __name__ == "__main__":
+  usage_msg1 = "Usage:\n"
+  usage_msg2 = "%s <elements_name> : Print network elements with name of <elements_name>\n" % (sys.argv[0])
+  usage_msg3 = "    Valid element names:\n"
+  usage_msg4 = "        all              : Print all network elements\n"
+  usage_msg5 = "        switches         : Print all switches and ports\n"
+  usage_msg6 = "        links            : Print all links\n"
+  usage_msg = usage_msg1 + usage_msg2 + usage_msg3 + usage_msg4 + usage_msg5
+  usage_msg = usage_msg + usage_msg6
+
+  # Usage info
+  if len(sys.argv) > 1 and (sys.argv[1] == "-h" or sys.argv[1] == "--help"):
+    print(usage_msg)
+    exit(0)
+
+  # Check arguments
+  if len(sys.argv) < 2:
+    log_error(usage_msg)
+    exit(1)
+
+  if (sys.argv[1] != "all" and sys.argv[1] != "switches" and sys.argv[1] != "links"):
+    log_error(usage_msg)
+    exit(1)
+
+  # Do the work
+  if (sys.argv[1] == "all" or sys.argv[1] == "switches"):
+    get_network_switches()
+  if (sys.argv[1] == "all" or sys.argv[1] == "links"):
+    get_network_links()