blue86321 / aws-ecs-demo-terraform-ci-cd

AWS ECS Demo with CI/CD Pipeline by GitHub Actions

Introduction

• This repository is a demo to deploy applications on AWS using Terraform with CI/CD pipeline from GitHub Actions to trigger re-deploy.

Architecture

• We spin up the application in containers via AWS Elastic Container Service (ECS) in FARGATE (Serverless EC2)
• Images are stored in Elastic Container Registry (ECR) providing to FARGATE if needed
• A PostgresSQL database is deployed using Relational Database Service (RDS), which is put in private subnets

Demo Architecture

Client Routes

• Requests first go to Internet Gateway (IGW) and route to Application Load Balancer (ALB) by route table config
• ALB forward requests to Target Groups which links to application ports in FARGATE
• Only applications (security group) can connect to RDS if needed

Developer Routes

• Code changes in applications commit to GitHub repository
• GitHub Actions (CI/CD pipeline) get triggered
  • CI: build images and send to private ECR (similar to Docker Hub)
  • CD: prepare new task definition (config to run a container) and send to ECS, and then ask ECS to re-deploy containers

How to Run

Prerequisites

• Terraform
• GitHub CLI
• Fork the repo under your GitHub account since we need repo variables to run GitHub Actions

Setup AWS Config

# Terraform AWS access
export AWS_ACCESS_KEY_ID="<YOUR_KEY>"
export AWS_SECRET_ACCESS_KEY="<YOUR_SECRET>"

Apply AWS Config

• Apply Terraform

cd terraform

# Terraform Variables
cp terraform.tfvars.example terraform.tfvars
# Replace "GITHUB_ACCOUNT" to your actual github account
sed -i '' -e 's/<USERNAME>/GITHUB_ACCOUNT/g' terraform.tfvars

# Apply Terraform Config for AWS
terraform init
terraform apply --auto-approve

• When Terraform is done (~ 10min), wait another 30s, then visit ALB endpoint
• You should see default Nginx welcome page

echo "http://$(terraform output -raw alb_dns_name)"

Nginx welcome page

Setup GitHub Config

gh variable set AWS_REGION --body "$(terraform output -raw aws_region)"
gh variable set AWS_IAM_ROLE --body "$(terraform output -raw github_actions_role_arn)"
gh variable set ECS_CLUSTER_NAME --body "$(terraform output -raw ecs_cluster_name)"

Trigger GitHub Actions for Actual Application Deployment

• Modify any file under /web_backend folder
• Commit the changes and push to origin master branch, which will trigger CI/CD pipeline we defined

cd ..  # Go back to repo root directory
echo "" >> ./web_backend/README.md  # modification example
git add . && git commit -m "docs: modify web_backend README" && git push origin master

---

• Check GitHub CI/CD, when it's done (~ 10min), visit ALB endpoint with /docs suffix, you should see results from application

cd terraform
echo "http://$(terraform output -raw alb_dns_name)/docs"

Application content page

• Visit ALB endpoint to see load balance (Clear browser cache if you still see nginx page)

echo "http://$(terraform output -raw alb_dns_name)"

Machine 1
Machine 2

• Any changes under web_backend folder will trigger CI/CD pipeline and re-deploy AWS ECS containers

Destroy

terraform destroy --auto-approve