Added complete code with example and READMEs

.gitignore

+.terraform
+terraform.tfstate
+*.tfstate*
+terraform.tfvars

LICENSE

+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

README.md

-# terraform-aws-ec2
-Terraform module which creates EC2 instance on AWS
+AWS EC2 Terraform module
+========================
+
+Terraform module which creates EC2 instance(s) on AWS.
+
+These types of resources are supported:
+
+* [VPC](https://www.terraform.io/docs/providers/aws/r/vpc.html)
+* [Subnet](https://www.terraform.io/docs/providers/aws/r/aws_subnet.html)
+* [Route](https://www.terraform.io/docs/providers/aws/r/route.html)
+* [Route table](https://www.terraform.io/docs/providers/aws/r/route_table.html)
+* [Internet Gateway](https://www.terraform.io/docs/providers/aws/r/internet_gateway.html) 
+* [NAT Gateway](https://www.terraform.io/docs/providers/aws/r/nat_gateway.html)
+* [VPC Endpoint](https://www.terraform.io/docs/providers/aws/r/vpc_endpoint.html) (S3 and DynamoDB)
+* [RDS DB Subnet Group](https://www.terraform.io/docs/providers/aws/r/db_subnet_group.html) 
+* [ElastiCache Subnet Group](https://www.terraform.io/docs/providers/aws/r/elasticache_subnet_group.html) 
+
+Usage
+-----
+
+```hcl
+module "ec2" {
+  source = "terraform-aws-modules/ec2/aws"
+
+  name  = "my-cluster"
+  count = 5
+  
+  ami                    = "ami-ebd02392"
+  instance_type          = "t2.micro"
+  key_name               = "user1"
+  monitoring             = true
+  vpc_security_group_ids = ["sg-12345678"]
+
+  tags = {
+    Terraform = "true"
+    Environment = "dev"
+  }
+}
+```
+
+Examples
+========
+
+* [Basic EC2 instance](examples/basic)
+
+Authors
+=======
+
+Module managed by [Anton Babenko](https://github.com/antonbabenko).
+
+License
+=======
+
+Apache 2 Licensed. See LICENSE for full details.
\ No newline at end of file

examples/basic/README.md

+Basic EC2 instance
+==================
+
+Configuration in this directory creates single EC2 instance with minimum set of arguments: AMI ID and instance type.
+
+Unspecified arguments for security group id and subnet are inherited from the default VPC.
+
+This example outputs instance id and public DNS name as a single value and as a list.
+
+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.

examples/basic/main.tf

+provider "aws" {
+  region = "eu-west-1"
+}
+
+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 "ec2" {
+  source = "../../"
+
+  name          = "example"
+  ami           = "${data.aws_ami.amazon_linux.id}"
+  instance_type = "t2.micro"
+}

examples/basic/outputs.tf

+output "id" {
+  description = "List of IDs of instances"
+  value       = ["${module.ec2.id}"]
+}
+
+output "public_dns" {
+  description = "List of public DNS names assigned to the instances"
+  value       = ["${module.ec2.public_dns}"]
+}
+
+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]}"
+}

main.tf

+######
+# EC2 instance
+######
+resource "aws_instance" "this" {
+  count = "${var.count}"
+
+  ami                    = "${var.ami}"
+  instance_type          = "${var.instance_type}"
+  user_data              = "${var.user_data}"
+  subnet_id              = "${var.subnet_id}"
+  key_name               = "${var.key_name}"
+  monitoring             = "${var.monitoring}"
+  vpc_security_group_ids = ["${var.vpc_security_group_ids}"]
+  iam_instance_profile   = "${var.iam_instance_profile}"
+
+  associate_public_ip_address = "${var.associate_public_ip_address}"
+  private_ip                  = "${var.private_ip}"
+  ipv6_address_count          = "${var.ipv6_address_count}"
+  ipv6_addresses              = "${var.ipv6_addresses}"
+
+  ebs_optimized          = "${var.ebs_optimized}"
+  volume_tags            = "${var.volume_tags}"
+  root_block_device      = "${var.root_block_device}"
+  ebs_block_device       = "${var.ebs_block_device}"
+  ephemeral_block_device = "${var.ephemeral_block_device}"
+
+  source_dest_check                    = "${var.source_dest_check}"
+  disable_api_termination              = "${var.disable_api_termination}"
+  instance_initiated_shutdown_behavior = "${var.instance_initiated_shutdown_behavior}"
+  availability_zone                    = "${var.availability_zone}"
+  placement_group                      = "${var.placement_group}"
+  tenancy                              = "${var.tenancy}"
+
+  # Note: network_interface can't be specified together with associate_public_ip_address
+  # network_interface = "${var.network_interface}"
+
+  tags = "${merge(var.tags, map("Name", format("%s-%d", var.name, count.index+1)))}"
+}

outputs.tf

+output "id" {
+  description = "List of IDs of instances"
+  value       = ["${aws_instance.this.*.id}"]
+}
+
+output "availability_zone" {
+  description = "List of availability zones of instances"
+  value       = ["${aws_instance.this.*.availability_zone}"]
+}
+
+output "placement_group" {
+  description = "List of placement groups of instances"
+  value       = ["${aws_instance.this.*.placement_group}"]
+}
+
+output "key_name" {
+  description = "List of key names of instances"
+  value       = ["${aws_instance.this.*.key_name}"]
+}
+
+output "public_dns" {
+  description = "List of public DNS names assigned to the instances. For EC2-VPC, this is only available if you've enabled DNS hostnames for your VPC"
+  value       = ["${aws_instance.this.*.public_dns}"]
+}
+
+output "public_ip" {
+  description = "List of public IP addresses assigned to the instances, if applicable"
+  value       = ["${aws_instance.this.*.public_ip}"]
+}
+
+output "network_interface_id" {
+  description = "List of IDs of the network interface of instances"
+  value       = ["${aws_instance.this.*.network_interface_id}"]
+}
+
+output "primary_network_interface_id" {
+  description = "List of IDs of the primary network interface of instances"
+  value       = ["${aws_instance.this.*.primary_network_interface_id}"]
+}
+
+output "private_dns" {
+  description = "List of private DNS names assigned to the instances. Can only be used inside the Amazon EC2, and only available if you've enabled DNS hostnames for your VPC"
+  value       = ["${aws_instance.this.*.private_dns}"]
+}
+
+output "private_ip" {
+  description = "List of private IP addresses assigned to the instances"
+  value       = ["${aws_instance.this.*.private_ip}"]
+}
+
+output "security_groups" {
+  description = "List of associated security groups of instances"
+  value       = ["${aws_instance.this.*.security_groups}"]
+}
+
+output "vpc_security_group_ids" {
+  description = "List of associated security groups of instances, if running in non-default VPC"
+  value       = ["${aws_instance.this.*.vpc_security_group_ids}"]
+}
+
+output "subnet_id" {
+  description = "List of IDs of VPC subnets of instances"
+  value       = ["${aws_instance.this.*.}"]
+}

variables.tf

+variable "name" {
+  description = "Name to be used on all resources as prefix"
+}
+
+variable "count" {
+  description = "Number of instances to launch"
+  default     = 1
+}
+
+variable "ami" {
+  description = "ID of AMI to use for the instance"
+}
+
+variable "availability_zone" {
+  description = "The AZ to start the instance in"
+  default     = ""
+}
+
+variable "placement_group" {
+  description = "The Placement Group to start the instance in"
+  default     = ""
+}
+
+variable "tenancy" {
+  description = "The tenancy of the instance (if the instance is running in a VPC). Available values: default, dedicated, host."
+  default     = "default"
+}
+
+variable "ebs_optimized" {
+  description = "If true, the launched EC2 instance will be EBS-optimized"
+  default     = false
+}
+
+variable "disable_api_termination" {
+  description = "If true, enables EC2 Instance Termination Protection"
+  default     = false
+}
+
+variable "instance_initiated_shutdown_behavior" {
+  description = "Shutdown behavior for the instance" # https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/terminating-instances.html#Using_ChangingInstanceInitiatedShutdownBehavior
+  default     = ""
+}
+
+variable "instance_type" {
+  description = "The type of instance to start"
+}
+
+variable "key_name" {
+  description = "The key name to use for the instance"
+  default     = ""
+}
+
+variable "monitoring" {
+  description = "If true, the launched EC2 instance will have detailed monitoring enabled"
+  default     = false
+}
+
+variable "vpc_security_group_ids" {
+  description = "A list of security group IDs to associate with"
+  default     = []
+}
+
+variable "subnet_id" {
+  description = "The VPC Subnet ID to launch in"
+  default     = ""
+}
+
+variable "associate_public_ip_address" {
+  description = "If true, the EC2 instance will have associated public IP address"
+  default     = false
+}
+
+variable "private_ip" {
+  description = "Private IP address to associate with the instance in a VPC"
+  default     = ""
+}
+
+variable "source_dest_check" {
+  description = "Controls if traffic is routed to the instance when the destination address does not match the instance. Used for NAT or VPNs."
+  default     = true
+}
+
+variable "user_data" {
+  description = "The user data to provide when launching the instance"
+  default     = ""
+}
+
+variable "iam_instance_profile" {
+  description = "The IAM Instance Profile to launch the instance with. Specified as the name of the Instance Profile."
+  default     = ""
+}
+
+variable "ipv6_address_count" {
+  description = "A number of IPv6 addresses to associate with the primary network interface. Amazon EC2 chooses the IPv6 addresses from the range of your subnet."
+  default     = 0
+}
+
+variable "ipv6_addresses" {
+  description = "Specify one or more IPv6 addresses from the range of the subnet to associate with the primary network interface"
+  default     = []
+}
+
+variable "tags" {
+  description = "A mapping of tags to assign to the resource"
+  default     = {}
+}
+
+variable "volume_tags" {
+  description = "A mapping of tags to assign to the devices created by the instance at launch time"
+  default     = {}
+}
+
+variable "root_block_device" {
+  description = "Customize details about the root block device of the instance. See Block Devices below for details"
+  default     = []
+}
+
+variable "ebs_block_device" {
+  description = "Additional EBS block devices to attach to the instance"
+  default     = []
+}
+
+variable "ephemeral_block_device" {
+  description = "Customize Ephemeral (also known as Instance Store) volumes on the instance"
+  default     = []
+}
+
+variable "network_interface" {
+  description = "Customize network interfaces to be attached at instance boot time"
+  default     = []
+}