New dns script that supports multiple dns names for an elb.

util/vpc-tools/vpc_dns.py

+import boto
+from vpcutil import vpc_for_stack_name
+
+stack_name = 'testforumstack9'
+# Utility Functions
+
+
+def get_or_create_hosted_zone(zone_name):
+
+  r53 = boto.connect_route53()
+  hosted_zone = r53.get_hosted_zone_by_name(zone_name)
+
+  if not hosted_zone:
+    zone_data = r53.create_hosted_zone(zone_name,
+        comment="Created by automation.")
+    hosted_zone = r53.get_hosted_zone_by_name(zone_name)
+
+  return hosted_zone
+
+def elbs_for_stack_name(stack_name):
+  vpc_id = vpc_for_stack_name(stack_name)
+  elbs = boto.connect_elb()
+  for elb in elbs.get_all_load_balancers():
+    if elb.vpc_id == vpc_id:
+      yield elb
+
+def create_service_dns(elb, prefix, zone):
+  # Get all record sets in zone
+  r53 = boto.connect_route53(debug=2)
+
+  zone_id = zone.Id.replace("/hostedzone/","") 
+  records = r53.get_all_rrsets(zone_id)
+
+  old_names = [r.name[:-1] for r in records]
+  print(old_names)
+
+  dns_template = "{prefix}.{zone_name}"
+
+  # Have to remove the trailing period that is on zone names.
+  zone_name = zone.Name[:-1]
+  dns_name = dns_template.format(prefix=prefix,
+                                 zone_name=zone_name)
+
+  change_set = boto.route53.record.ResourceRecordSets()
+
+  # If the dns name already points to something.
+  # Delete the existing connection.
+  print(dns_name)
+  if dns_name in old_names:
+    print "adding delete"
+    change = change_set.add_change(
+      'DELETE',
+      dns_name,
+      'CNAME',
+      600)
+
+    change.add_value(elb.dns_name)
+
+  change = change_set.add_change(
+    'CREATE',
+    dns_name,
+    'CNAME',
+    600 )
+
+  change.add_value(elb.dns_name)
+
+  print change_set.to_xml()
+
+  r53.change_rrsets(zone_id, change_set.to_xml())
+
+
+# Create DNS for edxapp and xqueue.
+dns_settings = {
+  'edxapp'  : [ 'courses', 'studio' ],
+  'xqueue'  : [ 'xqueue' ],
+  'rabbit'  : [ 'rabbit' ],
+  'xserver' : [ 'xserver' ],
+  'worker'  : [ 'worker' ],
+}
+
+# Create a zone for the stack.
+zone_name = "{}.vpc.edx.org".format(stack_name)
+
+zone = get_or_create_hosted_zone(zone_name)
+
+stack_elbs = elbs_for_stack_name(stack_name)
+for elb in stack_elbs:
+  for service, dns_prefixes in dns_settings.items():
+    if service in elb.dns_name.lower():
+      for prefix in dns_prefixes:
+        create_service_dns(elb, prefix, zone)