add source code hash for s3 bucket (#8)

* add source code hash for s3 bucket

.gitignore

@@ -2,3 +2,4 @@
 **/.terraform
 **/*.tfstate*
 crash.log
+.idea/

main.tf

@@ -50,7 +50,7 @@ resource "aws_lambda_function" "main_s3" {
   description       = "Terraformed Lambda function."
   s3_bucket         = "${var.s3_bucket}"
   s3_key            = "${var.s3_key}"
-  s3_object_version = "${var.s3_object_version}"
+  s3_object_version = "${var.s3_trigger_updates == true ? data.aws_s3_bucket_object.main.version_id : "" }"
   handler           = "${var.handler}"
   runtime           = "${var.runtime}"
   memory_size       = "${var.memory_size}"
@@ -64,13 +64,18 @@ resource "aws_lambda_function" "main_s3" {
   tags = "${merge(var.tags, map("Name", "${var.name_prefix}"))}"
 }
 
+data "aws_s3_bucket_object" "main" {
+  bucket = "${var.s3_bucket}"
+  key    = "${var.s3_key}"
+}
+
 resource "aws_lambda_function" "vpc_s3" {
   count             = "${var.attach_vpc_config == "true" && var.filename == ""  ? 1 : 0}"
   function_name     = "${var.name_prefix}"
   description       = "Terraformed Lambda function."
   s3_bucket         = "${var.s3_bucket}"
   s3_key            = "${var.s3_key}"
-  s3_object_version = "${var.s3_object_version}"
+  s3_object_version = "${var.s3_trigger_updates == true ? data.aws_s3_bucket_object.main.version_id : "" }"
   handler           = "${var.handler}"
   runtime           = "${var.runtime}"
   memory_size       = "${var.memory_size}"

variables.tf

@@ -40,6 +40,7 @@ variable "vpc_id" {
 }
 
 variable "subnet_ids" {
+  type        = "list"
   description = "A list of subnet IDs associated with the Lambda function."
   default     = []
 }
@@ -64,6 +65,11 @@ variable "tags" {
   default     = {}
 }
 
+variable "s3_trigger_updates" {
+  description = "Trigger updates to lamda if S3 content has changed"
+  default     = "true"
+}
+
 variable "s3_object_version" {
   description = "The object version containing the function's deployment package. Conflicts with filename."
   default     = ""