Add nagios check for remaining IP addresses

Check currently assumes a single external network and checks for routers
with allocated IP's and floating IP's allocated

Change-Id: I6835de8b036ed5247994ebd904f63147dfef3d67

nagios-plugins/check_ip_pool.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python
+"""
+Check for remaining IP addresses
+"""
+# pylint: disable=import-error
+
+from neutronclient.v2_0 import client
+from ipaddress import ip_network
+import sys
+import argparse
+
+NAGIOS_OK = 0
+NAGIOS_WARNING = 1
+NAGIOS_CRITICAL = 2
+NAGIOS_UNKNOWN = 3
+
+def main():
+    """
+    Main script body
+    """
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-u', '--username', required=True)
+    parser.add_argument('-p', '--password', required=True)
+    parser.add_argument('-t', '--tenant_name', required=True)
+    parser.add_argument('-a', '--auth_url', required=True)
+    parser.add_argument('-w', '--warn', type=int, required=True)
+    parser.add_argument('-c', '--critical', type=int, required=True)
+    args = parser.parse_args()
+
+    neutron = client.Client(username=args.username, password=args.password,
+                            tenant_name=args.tenant_name,
+                            auth_url=args.auth_url)
+    neutron.format = 'json'
+
+    for arg in [args.warn, args.critical]:
+        if not 0 <= arg <= 100:
+            print "Alert parameters must be valid percentages"
+            sys.exit(NAGIOS_UNKNOWN)
+
+    # Get external network
+    # Assume a single external network for the minute
+    ext_net = [net for net in neutron.list_networks()['networks']
+               if net['router:external']]
+
+    total_addresses = 0
+    for subnet in neutron.show_network(ext_net[0]['id'])['network']['subnets']:
+        total_addresses += ip_network(neutron.show_subnet(subnet)
+                                      ['subnet']['cidr']).num_addresses
+
+    floating_ips = len(neutron.list_floatingips()['floatingips'])
+    router_ips = len([router for router in neutron.list_routers()['routers']
+                      if router['external_gateway_info']])
+
+    total_used = floating_ips + router_ips
+
+    percentage_used = 100 * total_used/total_addresses
+
+    if percentage_used >= args.warn:
+        code = NAGIOS_WARNING
+        msg = 'WARNING'
+    elif percentage_used >= args.critical:
+        code = NAGIOS_CRITICAL
+        msg = 'CRITICAL'
+    else:
+        code = NAGIOS_OK
+        msg = 'OK'
+
+    print '{0}: {1}% of IP pool used, '\
+            '{2} out of {5} addresses in use | '\
+            'total_used={2};{3};{4};;{5} '\
+            'total_available={5} '\
+            'floating_ips_used={6} '\
+            'ext_routers_used={7}'\
+            .format(msg, percentage_used, total_used,
+                    (total_addresses * args.warn)/100,
+                    (total_addresses * args.critical)/100,
+                    total_addresses, floating_ips, router_ips)
+    sys.exit(code)
+
+if __name__ == "__main__":
+    main()