Initial commit of listorphans.py script

listorphans.py lists certain 'orphaned' objects - routers, floating IPs,
subnets, and networks - present in Neutron.  Orphans in this context are
objects that exist but whose project ID is no longer valid, e.g tenants
that have been deleted.

Change-Id: I41ea6f115d0b7a1a84e7f23005d333d39b800beb

neutron/listorphans.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+
+import os
+import sys
+import keystoneclient.v2_0.client as ksclient
+import neutronclient.v2_0.client as nclient
+
+def usage():
+    print "listorphans.py <object> where object is one or more of",
+    print "'networks', 'routers', 'subnets', 'floatingips' or 'all'"
+
+def get_credentials():
+    d = {}
+    d['username'] = os.environ['OS_USERNAME']
+    d['password'] = os.environ['OS_PASSWORD']
+    d['auth_url'] = os.environ['OS_AUTH_URL']
+    d['tenant_name'] = os.environ['OS_TENANT_NAME']
+    return d
+
+credentials = get_credentials()
+neutron = nclient.Client(**credentials)
+keystone = ksclient.Client(**credentials)
+
+def get_orphaned_neutron_objects(object):
+    objects = getattr(neutron, 'list_' + object)()
+    orphans = []
+    for object in objects.get(object):
+        try:
+            keystone.tenants.get(object['tenant_id'])
+        # If the tenant ID doesn't exist, then this object is orphaned
+        except ksclient.exceptions.NotFound:
+            orphans.append(object['id'])
+    return orphans
+
+def main():
+    if len(sys.argv) > 1:
+        if sys.argv[1] == 'all':
+            objects = [ 'networks', 'routers', 'subnets', 'floatingips' ]
+        else:
+            objects = sys.argv[1:]
+        for object in objects:
+            orphans = get_orphaned_neutron_objects(object)
+            print len(orphans), 'orphan(s) found of type', object, '[%s]' % ', '.join(map(str, orphans))
+
+    else:
+        usage()
+        sys.exit(1)
+
+if __name__ == '__main__':
+    main()