Architecture Documentation

This document outlines the software and hardware requirements for running the infrastructure of the example app. You can refer to the Architecture Diagram for a visual overview of the infrastructure components.

Required Hardware

The infrastructure is hosted on AWS and relies on various AWS services, including ECS with Fargate launch type, RDS, and ElastiCache.

RDS Instance Type

• Instance Type: db.t3.medium

ElastiCache Node Type

• Node Type: cache.t2.micro

ECS Fargate Instance Type

The ECS Fargate instance type is dynamically determined based on the environment-specific file stored within the assets/ecs_configs folder. This file, named after the environment, dictates essential configurations for ECS. It encompasses settings like task_desired_count, web_container_cpu, web_container_memory, deployment_maximum_percent, deployment_minimum_healthy_percent, max_capacity, and max_cpu_threshold. These configurations must be explicitly defined within this designated file to accurately configure ECS behavior.

Required Software

The infrastructure is managed and modified using Terraform Cloud. Whenever code changes are pushed to the respective branch, a Terraform plan is automatically performed for the associated infrastructure version, based on the configured Version Control System (VCS) per workspace. The Terraform Working Directory specifies the location of the code to be applied.

• Changes to the develop branch trigger a plan for the staging workspace with modifications in the core module.
• Changes to the main branch activate the plan for the production workspace with changes in the core module.
• Any changes made to the develop or main branches within the shared folder will also trigger the plan.

Once the Terraform plan succeeds on Terraform Cloud, you can manually apply the changes to the infrastructure.

Workspaces Configuration

Three separate workspaces need to be configured:

1. shared: For shared services and resources across environments.
2. staging: For the staging version of the application.
3. production: For the production version of the application.

Version control connections should be set up for each workspace. The shared workspace should point to the shared folder, and both staging and production workspaces should point to the base folder.

Required Variables

All variables should be set as Terraform variables, and the 'sensitive' flag should be applied where necessary. The following variables are shared between all workspaces:

Variable	Value
AWS_ACCESS_KEY_ID	SENSITIVE
AWS_SECRET_ACCESS_KEY	SENSITIVE

These variables should be configured for staging and production workspaces. If both environments share those variables, you can set them in the Variable Sets.

Variable	Value
environment	staging
secret_key_base	SENSITIVE
rds_username	SENSITIVE
rds_password	SENSITIVE
redis_auth_token	SENSITIVE

The following variables should be configured for the shared workspace:

Variable	Value
environment	production