feat: Updated Lambda module to work with Terraform 0.13 (#99)

Author: antonbabenko

README.md

@@ -9,7 +9,9 @@ Doing serverless with Terraform? Check out [serverless.tf framework](https://ser
 
 ## Terraform versions
 
-Terraform 0.12. Pin module version to `~> v3.0`. Submit pull-requests to `master` branch.
+Terraform 0.13. Pin module version to `~> v4.0`. Submit pull-requests to `master` branch.
+
+Terraform 0.12. Pin module version to `3.4.0` (or older). Submit pull-requests to `terraform012` branch.
 
 Terraform 0.11. Pin module version to `~> v1.0`.
 
@@ -30,7 +32,7 @@ Terraform 0.11. Pin module version to `~> v1.0`.
 ```hcl
 module "notify_slack" {
   source  = "terraform-aws-modules/notify-slack/aws"
-  version = "~> 3.0"
+  version = "~> 4.0"
 
   sns_topic_name = "slack-topic"
 

examples/notify-slack-simple/main.tf

@@ -19,4 +19,6 @@ module "notify_slack" {
   tags = {
     Name = "notify-slack-simple"
   }
+
+  depends_on = [aws_sns_topic.my_sns]
 }

main.tf

@@ -67,7 +67,7 @@ resource "aws_sns_topic_subscription" "sns_notify_slack" {
 
 module "lambda" {
   source  = "terraform-aws-modules/lambda/aws"
-  version = ">= 1.18.0"
+  version = "1.18.0"
 
   create = var.create
 
@@ -104,6 +104,8 @@ module "lambda" {
   attach_policy_json            = true
   policy_json                   = element(concat(data.aws_iam_policy_document.lambda[*].json, [""]), 0)
 
+  use_existing_cloudwatch_log_group = true
+
   allowed_triggers = {
     AllowExecutionFromSNS = {
       principal  = "sns.amazonaws.com"
@@ -112,4 +114,6 @@ module "lambda" {
   }
 
   tags = merge(var.tags, var.lambda_function_tags)
+
+  depends_on = [aws_cloudwatch_log_group.lambda]
 }