Parameterizing EBS Block device (#34)

This should help help address #31

README.md

@@ -22,6 +22,7 @@ Module Input Variables
 **NOTE About User Data:** The `user_data` parameter overwrites the `user_data` template used by this module, this will break some of the module features (e.g. `docker_storage_size`, `dockerhub_token`, and `dockerhub_email`). However, `additional_user_data_script` will concatenate additional data to the end of the current `user_data` script. It is recomended that you use `additional_user_data_script`. These two parameters are mutually exclusive - you can not pass both into this module and expect it to work.
 
 - `additional_user_data_script` - Additional `user_data` scripts content
+- `ebs_block_device` - EBS block devices to attach to the instance. (default: /dev/xvdcz)
 - `region` - AWS Region - defaults to us-east-1
 - `servers`  - Number of ECS Servers to start in the cluster - defaults to 1
 - `min_servers`  - Minimum number of ECS Servers to start in the cluster - defaults to 1

main.tf

@@ -38,7 +38,7 @@ resource "aws_launch_configuration" "ecs" {
   associate_public_ip_address = "${var.associate_public_ip_address}"
 
   ebs_block_device {
-    device_name           = "/dev/xvdcz"
+    device_name           = "${var.ebs_block_device}"
     volume_size           = "${var.docker_storage_size}"
     volume_type           = "gp2"
     delete_on_termination = true

variables.tf

@@ -50,6 +50,11 @@ variable "enable_agents" {
   description = "Enable Consul Agent and Registrator tasks on each ECS Instance"
 }
 
+variable "ebs_block_device" {
+  default     = "/dev/xvdcz"
+  description = "EBS block devices to attach to the instance. (default: /dev/xvdcz)"
+}
+
 variable "extra_tags" {
   default = []
 }