Terraform for hello-world app

Objective

Setup hello-world app in a secure network which is served via the aws load-balancer.

Details on how terraform sets up the infrastructure

VPC

1. Creates VPC with 10.1.0.0/16 cidr block
2. A route table is created which routes all traffic to internet gateway
3. Two subnets are created with 10.1.1.0/24 and 10.1.4.0/24 cidr block and it is associated with previously created route table
4. A NAT gateway is created for private subnets
5. A route table is created which routes all traffic to NAT gateway
6. A private subnet with cidr block 10.1.2.0/24 and associated with previously created route table

EC2

Instance

A t2.micro instance is created in a private subnet with a user data which installs docker and starts the app on port 80. A security group is attached which allows incoming traffic to public subnets and outgoing to internet.

Application Load Balancer

1. Creates an application load balancer with following security groups

   • allows incoming traffic to port 80
   • allows outgoing traffic to private subnet range

2. Creates a target group A with port 80 with healthcheck path

3. Attaches target group A with t2.micro instance in which app is deployed

4. Adds a listener rule to foward the incoming requests to target group A

Instructions to use terraform

1. Install terraform version 0.12.19 via brew or asdf

2. Install awscli via brew

3. Create an IAM access keys with full access to EC2 and VPC and configure with your awscli client

   Run aws configure and set region to ap-south-1

4. Run terraform init to initializes all the plugins and modules

5. Run terraform plan to check the resources to be created

6. Run terraform apply to setup the complete infrastructure and to deploy the application

References

Architecture Diagram