guard regex against modules w/o event source

Author: moritzzimmer

modules/event/kinesis/main.tf

@@ -18,7 +18,7 @@ data "aws_iam_policy_document" "stream_policy_document" {
     resources = [
       // extracting 'arn:${Partition}:kinesis:${Region}:${Account}:stream/' from the kinesis stream ARN
       // see https://docs.aws.amazon.com/IAM/latest/UserGuide/list_amazonkinesis.html#amazonkinesis-resources-for-iam-policies
-      "${regex("arn.*\\/", var.event_source_arn)}*"
+      length(var.event_source_arn) > 0 ? "${regex("arn.*\\/", var.event_source_arn)}*" : ""
     ]
   }
 

modules/event/kinesis/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}