Introduction to Deploying Serverless Applications on AWS

Serverless architecture has revolutionized how applications are built and deployed, offering scalability, reduced operational costs, and faster time to market. As a leading cloud provider, AWS provides a comprehensive service suite enabling developers to build, deploy, and manage serverless applications. This blog post will guide you through deploying a serverless application on AWS using Terraform for infrastructure as code and GitHub Actions for continuous integration and deployment (CI/CD).

Prerequisites for Getting Started

Before diving into the implementation, it’s essential to ensure you have the necessary prerequisites:

  • AWS Account: An active AWS account is required to deploy and manage resources.
  • GitHub Account: To store your code and automate deployments, you’ll need a GitHub account.
  • Essential Knowledge: Familiarity with AWS services, Terraform, and CI/CD concepts will be helpful.
  • Local Development Environment: Ensure your local machine has the necessary tools installed, including AWS CLI, Terraform, and a text editor.

Required Tools and Services

To build and deploy your serverless application, you’ll need the following tools and services:

  • AWS Services: Lambda, API Gateway, DynamoDB, S3, IAM, Route 53, and AWS Amplify.
  • Terraform: This is for defining and managing your infrastructure as code.
  • GitHub Actions: For automating CI/CD workflows.
  • AWS CLI: To interact with AWS services from the command line.

Setting Up Your Development Environment

  1. Install Terraform: Download and install Terraform from the official Terraform website.
  2. Install AWS CLI: Follow the instructions on the AWS CLI installation guide.
  3. Configure AWS CLI: Set up your AWS CLI with your AWS credentials using the command aws configure.

Overview of the Serverless Application Architecture

Understanding AWS Services Involved

  • AWS Lambda: Executes backend logic in response to HTTP requests via API Gateway or events from other services.
  • API Gateway: This function acts as a front door for your application, managing API requests and routing them to appropriate Lambda functions.
  • DynamoDB: A fast and flexible NoSQL database for storing application data.
  • S3: Stores static assets like images, CSS, and JavaScript files.
  • Route 53: Provides domain management and DNS routing.
  • AWS Amplify: Simplifies frontend deployment, hosting, and integration with backend services.

High-Level Components and Their Roles

  • Frontend: Built using a JavaScript framework and hosted on AWS Amplify, with domain management via Route 53.
  • Backend: Consists of Lambda functions triggered by API Gateway, with data persistence in DynamoDB and static asset storage in S3.
  • Infrastructure: Defined using Terraform to ensure reproducibility and version control.

Detailed Implementation Steps

Initial Setup and Configuration

Creating an AWS IAM User

  1. Log in to the AWS Management Console.
  2. Navigate to IAM > Users > Add user.
  3. Create a user with programmatic access and attach the necessary policies for deploying resources.

Configuring the AWS Command Line Interface (CLI)

After creating the IAM user, configure the AWS CLI with the following command:

aws configure

Enter your AWS access key, secret key, region, and output format.

Infrastructure as Code with Terraform

Defining IAM Policies and Roles

Use Terraform to define IAM policies and roles required for your serverless application. Here’s an example:

resource “aws_iam_role” “lambda_execution_role” {

  name = “lambda_execution_role”

  

  assume_role_policy = jsonencode({

    Version = “2012-10-17”,

    Statement = [

      {

        Effect = “Allow”,

        Principal = {

          Service = “lambda.amazonaws.com”

        },

        Action = “sts:AssumeRole”

      }

    ]

  })

}

Establishing a Code Repository with AWS CodeCommit

If you prefer AWS-hosted repositories, create a CodeCommit repository using Terraform or the AWS Console.

Building the Frontend with AWS Amplify and Route 53

Hosting the Frontend Application

Use AWS Amplify to host your front-end application. You can deploy your code directly from GitHub, and Amplify will handle the build and deployment processes.

Domain Management and DNS Configuration

Configure your custom domain in Route 53 and link it to your Amplify app for seamless access.

Backend Implementation Using Lambda, API Gateway, DynamoDB, and S3

Developing Lambda Functions

Write your backend logic in Lambda functions triggered by API Gateway. Here’s a basic Node.js Lambda function:

exports.handler = async (event) => {

    return {

        statusCode: 200,

        body: JSON.stringify(‘Hello from Lambda!’),

    };

};

Setting Up API Endpoints

Use API Gateway to create and configure REST API endpoints that trigger your Lambda functions.

Database Design with DynamoDB

Design your DynamoDB tables to store application data efficiently. Use Terraform to automate the creation of these tables.

Storing Static Assets in S3 Buckets

Create an S3 bucket for storing and serving static assets, with public access settings as required.

Automating Deployment with GitHub Actions

Setting Up Continuous Integration and Continuous Deployment (CI/CD)

Create a GitHub Actions workflow file (.github/workflows/deploy.yml) to automate the deployment process. Here’s an example:

name: Deploy

on:

  push:

    branches:

      – main

jobs:

  deploy:

    runs-on: ubuntu-latest

    steps:

    – uses: actions/checkout@v2

    – name: Set up Terraform

      uses: hashicorp/setup-terraform@v1

    – name: Terraform Init

      run: terraform init

    – name: Terraform Apply

      run: terraform apply -auto-approve

Workflow Automation for Code Changes

With GitHub Actions, every push to the main branch will trigger the deployment workflow, ensuring your application is always up-to-date.

Best Practices and Considerations

Security Measures

  • Implementing Least Privilege Access Control: Ensure IAM roles and policies follow the principle of least privilege, granting only necessary permissions.
  • Ensuring Secure Communication: Use HTTPS for all API Gateway endpoints and enforce encryption for data at rest and in transit.

Cost Management Strategies

  • Monitoring and Optimizing Costs: Regularly review your AWS bills and optimize resource usage.
  • Leveraging Reserved Instances and Spot Instances: Use these options for predictable workloads to reduce costs.

Monitoring and Logging

  • Utilizing AWS CloudWatch for Observability: Set up CloudWatch logs and metrics to monitor application performance and detect issues.
  • Log Analysis and Alerting: Implement log analysis and alerting to stay informed about application health.

Testing and Validation

  • Infrastructure Testing with Terraform: Use Terraform’s plan and apply commands to validate your infrastructure changes.
  • Continuous Testing and Quality Assurance: Integrate unit and end-to-end tests into your CI/CD pipeline for ongoing validation.

Conclusion and Further Learning

Deploying serverless applications on AWS with Terraform and GitHub Actions allows for a seamless and automated workflow, ensuring your infrastructure is always in sync with your application code. You can build a robust, scalable, cost-effective serverless application by following the best practices and leveraging the tools and services mentioned.

References

Automate Microsoft web application deployments with GitHub Actions and Terraform

Scaling IaC and CI/CD pipelines with Terraform, GitHub Actions, and AWS Proton