Terraform Scripts for 3-Tier Application Architecture

This repository contains Terraform scripts to deploy a 3-tier application architecture on AWS. The architecture consists of ECS (Elastic Container Service) for frontend and backend containers, RDS (Relational Database Service) as the database, ECR (Elastic Container Registry) for Docker image repository, and ALB (Application Load Balancer) on top of the frontend.

For Practical Scenarios, refer my blog post: https://anyonecandeploy.com/

Target Audience

• If you already have frontend and backend application ready as an Docker Image, and planning to create 3 tier Infrastructure in AWS in one go, than you are on the right place

• Imagine you're excited to launch your application, but the overwhelming responsibility of deploying a secure, cost-effective, and automated infrastructure is hindering you. Don't worry! With just a few CLI commands and our carefully designed Terraform setup, you can get your application up and running quickly.

Prerequisites

Before you begin, make sure you have the following prerequisites installed:

• Terraform

• AWS CLI

• Docker (if you're building custom Docker images)

• Basic Working Knowledge of Terraform and AWS CLI required

Deployment Steps

Follow these steps to deploy the infrastructure using Terraform:

1. Clone this repository to your local machine:

   git clone [email protected]:var1914/automated-3-tier-infrastructure.git

2. Navigate to the repository directory:

   cd automated-3-tier-infrastructure

3. Initialize Terraform:

   terraform init

4. Go Through variables.tf, analyse what all variables you want to customise as per your needs

5. Review and modify file like stage.tfvars/prod.tfvars, add more variables in main.tf, if you are adding at stage.tfvars/prod.tfvars files to set your desired configurations. You may need to update variables such as region, AWS profile, etc on local machine.

Note: I have used temporary acm_certificate_arn inside stage/prod tfvars, please update it with actual one The automated script will only work if you have an ACM certs, as ALB HTTPS Listener requires TLS certificate. OR ELSE SCRIPT WILL FAIL

5. If you are planning to create multiple environment, its good to create terraform workspaces, which will make sure of isolation of your multiple duplicated environment

   For e.g.:
   terraform workspace new stage 
   OR
   terraform workspace new prod

Note: Terraform workspaces are a feature that allows you to manage multiple states of your infrastructure within a single Terraform directory, enabling you to switch between different sets of resources, variables, and outputs without interfering with each other.

5. Plan the Terraform configuration to review the infrastructure:

   terraform workspace select stage/prod
   terraform plan --var-file stage.tfvars/prod.tfvars

Note: Basically TFVARS define variables and their values for Terraform configurations, enabling dynamic parameterization of infrastructure resources

6. Apply the Terraform configuration to create the infrastructure:

   terraform workspace select stage/prod
   terraform apply --var-file stage.tfvars/prod.tfvars

7. Confirm the deployment by reviewing the Terraform Apply and entering 'yes' when prompted.

8. Once the deployment is complete, You need to push docker image.

Note: ALB will give 503 error, until you push frontend and backend docker images to ECR

9. Build and push your custom Docker images to ECR:

   # Login to ECR
   aws ecr get-login-password --region <REGION> | docker login --username AWS --password- stdin <AWS_ACCOUNT_ID>.dkr.ecr.<REGION>.amazonaws.com
   
   FOR FRONTEND: 
   
   # Build the Docker images
   docker build -t your-image-name .
   
   # Tag the Docker image for ECR
   docker tag your-image-name:latest <AWS_ACCOUNT_ID>.dkr.ecr.<REGION>.amazonaws.com/"${var.project_name}-${var.environment}-frontend":latest
   
   # Push to ECR
   docker push <AWS_ACCOUNT_ID>.dkr.ecr.<REGION>.amazonaws.com/"${var.project_name}-${var.environment}-frontend"
   
   FOR BACKEND: 
   
   # Build the Docker images
   docker build -t your-image-name .
   
   # Tag the Docker image for ECR
   docker tag your-image-name:latest <AWS_ACCOUNT_ID>.dkr.ecr.<REGION>.amazonaws.com/"${var.project_name}-${var.environment}-backend":latest
   
   # Push to ECR
   docker push <AWS_ACCOUNT_ID>.dkr.ecr.<REGION>.amazonaws.com/"${var.project_name}-${var.environment}-backend"
   
   

10. Access your application by mapping ALB DNS ( Which you will get from Terraform Output ) to your DNS.

Cleanup

To tear down the infrastructure and delete all resources created by Terraform, run:

```bash
terraform workspace select stage/prod
terraform destroy
```

Resources

No resources.

Inputs

Name	Description	Type	Default	Required
acm_certificate_arn	The ARN for the ACM certificate	string	n/a	yes
alb_public_access	Whether the ALB should be publicly accessible	bool	true	no
backend_readonly_root_filesystem	Whether the backend service should have a read-only root filesystem	bool	true	no
backend_service_cpu	The CPU units for the backend service	number	256	no
backend_service_environment	Environment variables for the backend service	list(map(string))	null	no
backend_service_memory	The memory for the backend service	number	512	no
backend_service_port	The port for the backend service	number	3000	no
create_env_bucket	Whether to create an environment bucket	bool	false	no
db_engine	The engine for the database	string	"postgres"	no
db_engine_version	The version for the database engine	string	"11.5"	no
db_instance_class	The instance class for the database	string	"db.t2.micro"	no
db_parameter_group_family	The family for the database parameter group	string	"postgres11"	no
db_port	The port for the database	number	5432	no
db_publicly_accessible	Whether the database should be publicly accessible	bool	false	no
db_storage_size	The storage size for the database	number	20	no
environment	The environment for the infrastructure	string	"stage"	no
frontend_service_cpu	The CPU units for the frontend service	number	256	no
frontend_service_environment	Environment variables for the frontend service	list(map(string))	null	no
frontend_service_memory	The memory for the frontend service	number	512	no
frontend_service_port	The port for the frontend service	number	80	no
project_name	The name of the project	string	n/a	yes
region	The region for the infrastructure	string	"us-west-2"	no
skip_final_snapshot	Whether to skip the final snapshot	bool	true	no
vpc_cidr	The CIDR block for the VPC	string	"10.0.0.0/16"	no

Outputs

Name	Description
alb_dns_name	The DNS name of the ALB
backend_ecr	The ECR URL for the backend
frontend_ecr	The ECR URL for the frontend