Deploying Serverless Applications on AWS with Terraform and Docker

In the ever-evolving landscape of cloud computing, serverless architecture has emerged as a game-changer. By abstracting server management, developers can focus on writing code without worrying about infrastructure. When combined with tools like AWS, Terraform, and Docker, deploying serverless applications becomes not only feasible but also efficient and scalable. In this article, we will explore how to deploy a serverless application using AWS Lambda, Terraform, and Docker, providing you with actionable insights and code examples to help you get started.

What is Serverless Architecture?

Serverless architecture allows developers to build and run applications without managing servers. With AWS Lambda, you can execute code in response to events, automatically scaling up or down based on demand. This means you only pay for the compute time you consume, making it cost-effective for many applications.

Key Benefits of Serverless Architecture

• Cost Efficiency: Pay only for what you use; no need to provision resources.
• Scalability: Automatically scales with the traffic, handling millions of requests seamlessly.
• Focus on Code: Developers can concentrate on writing business logic without worrying about server management.

What is Terraform?

Terraform is an Infrastructure as Code (IaC) tool that allows you to define and provision infrastructure using a declarative configuration language. With Terraform, you can manage AWS resources efficiently, ensuring consistency and repeatability in your deployments.

Advantages of Using Terraform

• Version Control: Infrastructure changes can be tracked using version control systems like Git.
• Reusability: Create reusable modules for different components of your infrastructure.
• Collaboration: Teams can collaborate more effectively with a clear definition of infrastructure.

What is Docker?

Docker is a containerization platform that allows developers to package applications and their dependencies into containers. This ensures that the application runs consistently across different environments. When deploying serverless applications, Docker can be used to create Lambda functions that run in a containerized environment.

Benefits of Using Docker

• Portability: Run containers anywhere, from local development to production environments.
• Isolation: Each container runs in its own environment, minimizing conflicts.
• Efficiency: Containers share the host OS kernel, making them lightweight and fast.

Use Case: Deploying a Serverless API

Let’s walk through deploying a simple serverless API using AWS Lambda, Terraform, and Docker. We will create a Node.js application that responds to HTTP requests.

Step 1: Setting Up Your Environment

Before we start coding, ensure you have the following tools installed:

• AWS CLI: For interacting with AWS services.
• Terraform: For infrastructure provisioning.
• Docker: For containerizing your application.
• Node.js: For developing your application.

Step 2: Creating the Node.js Application

Create a directory for your project and navigate into it:

mkdir serverless-api
cd serverless-api

Next, create a simple Node.js application. Create a file named index.js:

const response = (statusCode, message) => {
    return {
        statusCode: statusCode,
        body: JSON.stringify({ message: message })
    };
};

exports.handler = async (event) => {
    return response(200, "Hello, Serverless World!");
};

Step 3: Creating the Dockerfile

Now, let’s create a Dockerfile to package our application. Create a file named Dockerfile:

FROM public.ecr.aws/lambda/nodejs:14

COPY index.js package.json ./

CMD ["index.handler"]

Step 4: Building the Docker Image

Build the Docker image by running the following command:

docker build -t serverless-api .

Step 5: Writing Terraform Configuration

Next, we will define our infrastructure using Terraform. Create a file named main.tf:

provider "aws" {
  region = "us-west-2"
}

resource "aws_lambda_function" "serverless_api" {
  function_name = "serverless_api"
  image_uri     = "${aws_ecr_repository.repo.repository_url}:latest"
  package_type  = "Image"
  memory_size   = 128
  timeout       = 5

  environment {
    NODE_ENV = "production"
  }
}

resource "aws_ecr_repository" "repo" {
  name = "serverless-api"
}

Step 6: Deploying with Terraform

Initialize Terraform and deploy your infrastructure:

terraform init
terraform apply

Step 7: Push Docker Image to ECR

First, authenticate Docker to your Amazon ECR registry:

aws ecr get-login-password --region us-west-2 | docker login --username AWS --password-stdin <account-id>.dkr.ecr.us-west-2.amazonaws.com

Then, tag and push your Docker image:

docker tag serverless-api:latest <account-id>.dkr.ecr.us-west-2.amazonaws.com/serverless-api:latest
docker push <account-id>.dkr.ecr.us-west-2.amazonaws.com/serverless-api:latest

Step 8: Testing Your Serverless API

Once your deployment is complete, you can test your API. In the AWS Console, navigate to the Lambda function you created, where you can find the API Gateway URL. Use Postman or curl to send a request:

curl https://<api-id>.execute-api.us-west-2.amazonaws.com/Prod/

You should receive a response:

{"message":"Hello, Serverless World!"}

Troubleshooting Common Issues

• Deployment Errors: Ensure your AWS credentials are configured correctly and that you have the necessary permissions.
• Lambda Timeout: Double-check your timeout settings in the Terraform configuration.
• Image not found: Make sure the Docker image is pushed to ECR before deploying the Lambda function.

Conclusion

Deploying serverless applications on AWS using Terraform and Docker streamlines the development process and enhances your deployment capabilities. By abstracting infrastructure management and utilizing containerization, you can focus on building scalable applications that are cost-effective and efficient. With the steps outlined in this article, you are now equipped to create and deploy your own serverless applications on AWS. Happy coding!