🧐 ECS Express Mode vs Traditional ECS: A Hands-on Comparison with Terraform

ECS Express Mode vs Traditional ECS: A Hands-on Comparison with Terraform

AWS recently introduced ECS Express Mode, a simplified way to launch containerized applications with secure HTTPS endpoints. This new feature offers a more streamlined experience compared to traditional ECS, which requires manual configuration of various resources like load balancers, target groups, scaling policies, and more.

The key difference between the two lies in the level of automation and out-of-the-box features. ECS Express Mode automatically provisions essential resources, such as a Virtual Private Cloud (VPC), subnets, security groups, a load balancer, HTTPS configuration, auto-scaling policies, metrics, alarms, and health checks. This can lead to significant cost savings, as you only pay for the AWS resources your application actually uses.

Additionally, a single Application Load Balancer can be shared by up to 25 Express Mode services, further reducing costs.

To demonstrate the differences between the two approaches, we'll deploy a Flask portfolio website using three versions: v1 (foundation), v2 (advanced), and v3 (production). We'll use Terraform to manage the infrastructure for both traditional ECS and ECS Express Mode. Before we begin, ensure you have Terraform installed and configured with an AWS IAM account that has AdministratorAccess, along with basic knowledge of Python, Docker, and AWS ECS.

Prerequisites:

- Terraform installed and configured with an AWS IAM account that has AdministratorAccess

- Basic understanding of Python and Docker

- Familiarity with AWS ECS

Once you've met these requirements, let's dive into the practical demonstration.

Practical Demonstration

We'll start by cloning a repository containing three versions of the Flask portfolio website. Navigate to the ecs-express directory, which contains two subdirectories: traditional and express.

1. Traditional ECS

In the traditional directory, you'll find Terraform configurations for setting up a bare-minimum infrastructure for hosting the application. This setup includes:

- main.tf: Specifies AWS as the cloud provider.

- values.tf: Retrieves default VPC, subnets, and a security group with port 5000 open.

- ecs.tf: Creates the ECS cluster, IAM roles, task definition, and ECS service.

- get_ip.sh: A shell script that retrieves the public IP of the task's network interface and generates the URL with port 5000.

While this setup provides a basic infrastructure, it lacks production-grade features such as an Application Load Balancer, HTTPS, monitoring, alarms, and scaling policies.

For this demonstration, the Docker image is built for the AMD64 architecture. Ensure your Docker image is also built for AMD64, or use an ARM64 image with additional configuration.

2. Deploying Traditional ECS

To apply the traditional configuration, follow these steps:

- Navigate to the traditional directory.

- Run: `terraform init`

- Run: `terraform plan`

- Run: `terraform apply`

After a minute or two, your infrastructure should be up and running. To get the URL of the website, execute the get_ip.sh script and open the generated URL in your browser.

Updating the Application Version

To update your application to a newer version, simply update the Docker image version inside the ECS task definition. For example, switch from version v2 to version v1:

`image = pravesh2003/flask-portfolio:v1`

Then, apply the updated configuration using:

`terraform apply --auto-approve`

Finally, use the get_ip.sh script to access the updated version of your application.

3. ECS Express Mode

Now, let's take a look at the express directory, which contains Terraform configurations for ECS Express Mode. The main differences are:

- provider.tf: Specifies AWS as the cloud provider.

- express.tf: Contains the aws_ecs_express_gateway_service resource, which handles most of the Express Mode configuration.

- vars.tf: Contains variables such as the default VPC and its subnets.

- iam.tf: Contains the execution role for the Express Mode service.

While the traditional approach requires manual configuration of numerous resources, ECS Express Mode automates the provisioning of these resources, reducing setup time and potential errors. Additionally, Express Mode offers features like cost savings through shared Application Load Balancers and the ability to easily update application versions without changing the underlying infrastructure.

In conclusion, ECS Express Mode provides a more efficient and cost-effective way to deploy containerized applications compared to traditional ECS. By automating the creation of essential resources and offering additional features, Express Mode simplifies infrastructure management and reduces operational overhead.