151 lines
3.6 KiB
Markdown
151 lines
3.6 KiB
Markdown
---
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layout: "intro"
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page_title: "Basic Two-Tier AWS Architecture"
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sidebar_current: "examples-aws"
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---
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# Basic Two-Tier AWS Architecture
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This provides a template for running a simple two-tier architecture on Amazon
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Web services.
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The basic premise is you have stateless app servers running behind
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an ELB serving traffic.
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To simplify the example, this intentionally ignores deploying and
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getting your application onto the servers. However, you could do so either via
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[provisioners](/docs/provisioners/index.html) and a configuration
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management tool, or by pre-baking configured AMIs with
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[Packer](http://www.packer.io).
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After you run `terraform apply` on this configuration, it will
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automatically output the DNS address of the ELB. After your instance
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registers, this should respond with the default nginx web page.
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The configuration file contains comments describing each
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resource.
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## Command
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```
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terraform apply \
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-var 'aws_access_key=YOUR_ACCESS_KEY' \
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-var 'aws_secret_key=YOUR_SECRET_KEY' \
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-var 'key_path=/path/to/key/pair.pem' \
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-var 'key_name=keypair-name'
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```
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## Configuration
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```
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variable "aws_access_key" {}
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variable "aws_secret_key" {}
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variable "key_path" {}
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variable "key_name" {}
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variable "aws_region" {
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default = "us-west-2"
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}
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# Ubuntu Precise 12.04 LTS (x64)
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variable "aws_amis" {
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default = {
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"eu-west-1": "ami-b1cf19c6",
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"us-east-1": "ami-de7ab6b6",
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"us-west-1": "ami-3f75767a",
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"us-west-2": "ami-21f78e11"
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}
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}
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# Specify the provider and access details
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provider "aws" {
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access_key = "${var.aws_access_key}"
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secret_key = "${var.aws_secret_key}"
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region = "${var.aws_region}"
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}
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# Our default security group to access
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# the instances over SSH and HTTP
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resource "aws_security_group" "default" {
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name = "terraform_example"
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description = "Used in the terraform"
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# SSH access from anywhere
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ingress {
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from_port = 22
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to_port = 22
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protocol = "tcp"
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cidr_blocks = ["0.0.0.0/0"]
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}
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# HTTP access from anywhere
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ingress {
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from_port = 80
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to_port = 80
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protocol = "tcp"
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cidr_blocks = ["0.0.0.0/0"]
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}
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}
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resource "aws_elb" "web" {
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name = "terraform-example-elb"
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# The same availability zone as our instance
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availability_zones = ["${aws_instance.web.availability_zone}"]
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listener {
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instance_port = 80
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instance_protocol = "http"
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lb_port = 80
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lb_protocol = "http"
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}
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# The instance is registered automatically
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instances = ["${aws_instance.web.id}"]
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}
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resource "aws_instance" "web" {
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# The connection block tells our provisioner how to
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# communicate with the resource (instance)
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connection {
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# The default username for our AMI
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user = "ubuntu"
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# The path to your keyfile
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key_file = "${var.key_path}"
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}
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instance_type = "m1.small"
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# Loookup the correct AMI based on the region
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# we specified
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ami = "${lookup(var.aws_amis, var.aws_region)}"
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# The name of our SSH keypair you've created and downloaded
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# from the AWS console.
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#
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# https://console.aws.amazon.com/ec2/v2/home?region=us-west-2#KeyPairs:
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#
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key_name = "${var.key_name}"
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# Our Security group to allow HTTP and SSH access
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security_groups = ["${aws_security_group.default.name}"]
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# We run a remote provisioner on the instance after creating it.
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# In this case, we just install nginx and start it. By default,
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# this should be on port 80
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provisioner "remote-exec" {
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inline = [
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"sudo apt-get -y update",
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"sudo apt-get -y install nginx",
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"sudo service nginx start",
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]
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}
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}
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output "address" {
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value = "${aws_elb.web.dns_name}"
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}
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```
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