Added example of EBS volume attachment (related to #46) (#47)

README.md

@@ -32,8 +32,9 @@ module "ec2_cluster" {
 ## Examples
 
 * [Basic EC2 instance](https://github.com/terraform-aws-modules/terraform-aws-ec2-instance/tree/master/examples/basic)
+* [EC2 instance with EBS volume attachment](https://github.com/terraform-aws-modules/terraform-aws-ec2-instance/tree/master/examples/volume-attachment)
 
-## Make an encrypted ami for use
+## Make an encrypted AMI for use
 
 This module does not sopport encrypted AMI's out of the box however it is easy enough for you to generate one for use
 
@@ -76,10 +77,11 @@ data "aws_ami" "ubuntu-xenial" {
 ```
 
 
-## Limitations
+## Notes
 
 * `network_interface` can't be specified together with `associate_public_ip_address`, which makes `network_interface`
   not configurable using this module at the moment
+* Changes in `ebs_block_device` argument will be ignored. Use [aws_volume_attachment](https://www.terraform.io/docs/providers/aws/r/volume_attachment.html) resource to attach and detach volumes from AWS EC2 instances. See [this example](https://github.com/terraform-aws-modules/terraform-aws-ec2-instance/tree/master/examples/volume-attachment).
 
 <!-- BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK -->
 

examples/volume-attachment/README.md

+# EC2 instance with EBS volume attachment
+
+Configuration in this directory creates EC2 instances, EBS volume and attach it together.
+
+Unspecified arguments for security group id and subnet are inherited from the default VPC.
+
+This example outputs instance id and EBS volume id.
+
+## Usage
+
+To run this example you need to execute:
+
+```bash
+$ terraform init
+$ terraform plan
+$ terraform apply
+```
+
+Note that this example may create resources which can cost money. Run `terraform destroy` when you don't need these resources.
+
+<!-- BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK -->
+
+## Outputs
+
+| Name | Description |
+|------|-------------|
+| ebs_volume_attachment_id | The volume ID |
+| ebs_volume_attachment_instance_id | The instance ID |
+| instance_id | EC2 instance ID |
+| instance_public_dns | Public DNS name assigned to the EC2 instance |
+
+<!-- END OF PRE-COMMIT-TERRAFORM DOCS HOOK -->

examples/volume-attachment/main.tf

+provider "aws" {
+  region = "eu-west-1"
+}
+
+##################################################################
+# Data sources to get VPC, subnet, security group and AMI details
+##################################################################
+data "aws_vpc" "default" {
+  default = true
+}
+
+data "aws_subnet_ids" "all" {
+  vpc_id = "${data.aws_vpc.default.id}"
+}
+
+data "aws_ami" "amazon_linux" {
+  most_recent = true
+
+  filter {
+    name = "name"
+
+    values = [
+      "amzn-ami-hvm-*-x86_64-gp2",
+    ]
+  }
+
+  filter {
+    name = "owner-alias"
+
+    values = [
+      "amazon",
+    ]
+  }
+}
+
+module "security_group" {
+  source = "terraform-aws-modules/security-group/aws"
+
+  name        = "example"
+  description = "Security group for example usage with EC2 instance"
+  vpc_id      = "${data.aws_vpc.default.id}"
+
+  ingress_cidr_blocks = ["0.0.0.0/0"]
+  ingress_rules       = ["http-80-tcp", "all-icmp"]
+  egress_rules        = ["all-all"]
+}
+
+module "ec2" {
+  source = "../../"
+
+  instance_count = 1
+
+  name                        = "example-with-ebs"
+  ami                         = "${data.aws_ami.amazon_linux.id}"
+  instance_type               = "m4.large"
+  subnet_id                   = "${element(data.aws_subnet_ids.all.ids, 0)}"
+  vpc_security_group_ids      = ["${module.security_group.this_security_group_id}"]
+  associate_public_ip_address = true
+}
+
+resource "aws_volume_attachment" "this_ec2" {
+  device_name = "/dev/sdh"
+  volume_id   = "${aws_ebs_volume.this.id}"
+  instance_id = "${module.ec2.id[0]}"
+}
+
+resource "aws_ebs_volume" "this" {
+  availability_zone = "${module.ec2.availability_zone[0]}"
+  size              = 1
+}

examples/volume-attachment/outputs.tf

+output "instance_id" {
+  description = "EC2 instance ID"
+  value       = "${module.ec2.id[0]}"
+}
+
+output "instance_public_dns" {
+  description = "Public DNS name assigned to the EC2 instance"
+  value       = "${module.ec2.public_dns[0]}"
+}
+
+output "ebs_volume_attachment_id" {
+  description = "The volume ID"
+  value       = "${aws_volume_attachment.this_ec2.volume_id}"
+}
+
+output "ebs_volume_attachment_instance_id" {
+  description = "The instance ID"
+  value       = "${aws_volume_attachment.this_ec2.instance_id}"
+}