shawnsw / terraform-coreos-aws-ha

An example of deploying an HA webapp on AWS with Terraform and CoreOS.

HA webapp on AWS with Terraform and CoreOS

This is an example of deploying an HA webapp on AWS with Terraform and CoreOS.

Web server

• CoreOS instance bootstrapped using ignition.
• Runs web server as a systemd service with nginx container.
• Nginx config, custom 404 page and default index page are bootstrapped and mounted into the container (For demo purpose only, images should be built and pushed to registry.)

Jumpbox

• A public facing host that allows system admins to management instances in the same VPC.

Application Load Balancer

• ALB load balances web traffic to all web servers across multiple AZs
• Terminates SSL at ALB
• Two listners. Reidrects HTTP to HTTPS
• Communication between ALB and web servers is HTTP

Auto Scaling Group

• Loads launch configuration from rendered Ignition config
• Auto scales web instances across multiple AZs
• Attaches to afore created ALB

SSL

• Self signed certs
• Imported into ACM

Traffic flow

Users

 | http / https

ALB (http -> https)

 | http

Instances

How to run this

• Set up proper AWS creds
• Modify vars.tf accordingly
• Run terraform

terraform init
terraform plan
terraform apply

SSH key for access intances

SSH private key is genreated by Terraform. To get the private key, you can run the following command:

terraform state show tls_private_key.ssh