Version 0.2.1 - Added SNS logic and additional SNS publish statement

code/ddns-lambda.py

@@ -72,7 +72,7 @@
 LOGGER = logging.getLogger()
 ACCOUNT = None
 REGION = None
-VERSION = '0.2.0'
+VERSION = '0.2.1'
 
 # Read Env variables
 DEBUG_LOG_LEVEL = os.environ.get('DebugLogLevel', 'INFO')
@@ -85,6 +85,8 @@
 DNS_RR_TTL = 60 if DNS_RR_TTL == 0 else DNS_RR_TTL
 TF_MODULE_VERSION = os.environ.get('tf_module_version', '(unknown)')
 MAX_API_RETRY = int(os.environ.get('MaxApiRetry', '10'))
+
+# for SNS topic
 SNS_TOPIC_ARN = os.environ.get('SnsTopicArn', '')
 SNS_ENABLE = (os.environ.get('SnsEnable', 'False').lower() in [
               'yes', 'y', 'true', '1']) and SNS_TOPIC_ARN != ''
@@ -199,17 +201,26 @@ def lambda_handler(
     """
     LOGGER.info("event: %s", str(event) + lineno())
     LOGGER.info("context: %s", str(context) + lineno())
+    LOGGER.info("Sns Topic Mode: %s, sending to %s", str(SNS_ENABLE), SNS_TOPIC_ARN)
 
     caller_response = []
     # Checking to make sure there is a dynamodb table named in the Env Variable
     tables = list_tables(dynamodb_client)
 
     LOGGER.info("tables: %s", str(tables))
     if DDBNAME in tables['TableNames']:
-        LOGGER.info('DynamoDB table already exists')
+        LOGGER.info('DynamoDB table already exists: %s', DDBNAME)
     else:
-        LOGGER.info('DynamoDB table does not exist, exiting function: %s', DDBNAME)
-        return None
+        LOGGER.error('DynamoDB table does not exist, exiting function: %s', DDBNAME)
+        caller_response.append('DynamoDB table does not exist, exiting function: ' + DDBNAME)
+        if SNS_ENABLE:
+            sns_msg = {}
+            sns_msg['instance_id'] = event['detail']['instance-id']
+            sns_msg['account_id'] = get_caller_account_id()
+            sns_msg['region'] = event['region']
+            sns_msg['message'] = 'DynamoDB table does not exist: ' + DDBNAME
+            publish_to_sns(sns_client, json.dumps(sns_msg))
+        return caller_response
 
     # Set variables
     # Get the state from the Event stream
@@ -325,8 +336,19 @@ def lambda_handler(
     LOGGER.debug("subnet_mask: %s", str(subnet_mask) + lineno())
     reversed_ip_address = reverse_list(private_ip)
 
+    if reversed_ip_address == None:
+        LOGGER.error("Error in getting reverse IP address for: %s", str(private_ip) + lineno())
+        caller_response.append("Error in getting reverse IP address for: " + str(private_ip))
+        return caller_response
+
     reversed_domain_prefix = get_reversed_domain_prefix(subnet_mask, private_ip)
     reversed_domain_prefix = reverse_list(reversed_domain_prefix)
+
+    if reversed_domain_prefix == None:
+        LOGGER.error("Error in getting reverse domain prefix for: %s", str(private_ip) + lineno())
+        caller_response.append("Error in getting reverse domain prefix for: " + str(private_ip))
+        return caller_response
+
     LOGGER.debug("reversed_domain_prefix is: %s",
                  str(reversed_domain_prefix) + lineno())
     # Set the reverse lookup zone
@@ -341,14 +363,34 @@ def lambda_handler(
     if is_dns_hostnames_enabled(compute, vpc_id):
         LOGGER.debug("DNS hostnames enabled for %s", str(vpc_id) + lineno())
     else:
-        LOGGER.debug(
-            "DNS hostnames disabled for %s. You have to enable DNS hostnames to use Route 53 private hosted zones. %s", vpc_id, lineno())
+        LOGGER.error("DNS hostnames disabled for %s. You have to enable DNS hostnames to use Route 53 private hosted zones. %s", vpc_id, lineno())
+        caller_response.append("You have to enable DNS hostnames to use Route 53 private hosted zones. DNS hostnames disabled for " + vpc_id)
+        if SNS_ENABLE:
+            sns_msg = {}
+            sns_msg['instance_id'] = instance_id
+            sns_msg['account_id'] = account_id
+            sns_msg['region'] = region
+            sns_msg['client'] = 'ec2'
+            sns_msg['boto3_method'] = 'describe_vpc_attribute'
+            sns_msg['message'] = "You have to enable DNS hostnames to use Route 53 private hosted zones. DNS hostnames disabled for " + vpc_id
+            publish_to_sns(sns_client, json.dumps(sns_msg))
+        return caller_response
+
     if is_dns_support_enabled(compute, vpc_id):
         LOGGER.debug("DNS support enabled for %s", str(vpc_id) + lineno())
     else:
-        LOGGER.debug("DNS support disabled for %s.  You have to enabled DNS support to use Route 53 private hosted zones. %s", str(
-            vpc_id), lineno())
-        exit()
+        LOGGER.error("DNS support disabled for %s.  You have to enabled DNS support to use Route 53 private hosted zones. %s", vpc_id, lineno())
+        caller_response.append("You have to enabled DNS support to use Route 53 private hosted zones. DNS support disabled for " + vpc_id)
+        if SNS_ENABLE:
+            sns_msg = {}
+            sns_msg['instance_id'] = instance_id
+            sns_msg['account_id'] = account_id
+            sns_msg['region'] = region
+            sns_msg['client'] = 'ec2'
+            sns_msg['boto3_method'] = 'describe_vpc_attribute'
+            sns_msg['message'] = "You have to enabled DNS support to use Route 53 private hosted zones. DNS support disabled for " + vpc_id
+            publish_to_sns(sns_client, json.dumps(sns_msg))
+        return caller_response
 
     # These are collections of zones in Route 53.
     hosted_zones = new_list_hosted_zones(route53, instance_id)
@@ -431,14 +473,17 @@ def lambda_handler(
     except BaseException as err:
         LOGGER.error("instance: %s, No DHCP option set assigned to this VPC %s\n",
                      instance_id, str(err) + lineno())
+        caller_response.append('No DHCP option set assigned to this VPC %s' + vpc_id)
         if SNS_ENABLE:
             sns_msg = {}
             sns_msg['instance_id'] = instance_id
+            sns_msg['account_id'] = account_id
+            sns_msg['region'] = region
             sns_msg['client'] = 'ec2'
             sns_msg['boto3_method'] = 'describe_vpcs'
             sns_msg['message'] = 'No DHCP option set assigned to this VPC: ' + vpc_id
-            publish_to_sns(get_sns_client(), json.dumps(sns_msg))
-        exit()
+            publish_to_sns(sns_client, json.dumps(sns_msg))
+        return caller_response
 
     # Look to see whether there's a DHCP option set assigned to
     # the VPC.  Obtain the zone name, and check if there is a Private Hosted Zone
@@ -824,7 +869,6 @@ def lambda_handler(
             LOGGER.error("instance: %s, unexpected error. %s\n",
                          instance_id, str(err) + lineno())
 
-#    elif state == 'terminated':
     else:  # not running so delete the records
         # delete A record
         try:
@@ -1590,6 +1634,7 @@ def new_change_resource_recordset(client, instance_id, zone_id, host_name, hoste
             try:
                 sns_msg = {}
                 sns_msg['instance_id'] = instance_id
+                sns_msg['account_id'] = get_caller_account_id()
                 sns_msg['client'] = 'route53'
                 sns_msg['boto3_method'] = 'change_resource_record_sets'
                 sns_msg['message'] = 'change_resource_record_sets could not UPSERT record'
@@ -1901,6 +1946,7 @@ def new_delete_resource_record(client, instance_id, zone_id, host_name, hosted_z
             try:
                 sns_msg = {}
                 sns_msg['instance_id'] = instance_id
+                sns_msg['account_id'] = get_caller_account_id()                
                 sns_msg['client'] = 'route53'
                 sns_msg['boto3_method'] = 'change_resource_record_sets'
                 sns_msg['message'] = 'change_resource_record_sets could not DELETE record'
@@ -2117,10 +2163,12 @@ def reverse_list(ip_list):
             LOGGER.debug("returning: %s", str(reversed_list) + lineno())
             return reversed_list
 
-        LOGGER.info('Not a valid ip')
-        exit()
+        LOGGER.error('Not a valid ip. %s', lineno())
+        return None
+
     except:
-        LOGGER.info("unexpected error. %s\n", str(sys.exc_info()[0]) + lineno())
+        LOGGER.error("unexpected error. %s\n", str(sys.exc_info()[0]) + lineno())
+        return None
 
 
 def get_reversed_domain_prefix(subnet_mask, private_ip):