Tech Culture

AWS Lambda is a serverless computing platform that allows you to run your code without having to manage any infrastructure. With Lambda, you can build and run applications and services with ease, and pay only for the compute time that you consume.

In this article, we will look at how to create a Ruby-based Lambda function and how to interact with other AWS services from within your function.

Prerequisites

Before you start, you’ll need an AWS account and access to the AWS Management Console. You’ll also need some basic knowledge of the Ruby programming language.

Step 1: Create a new Lambda function

To create a new Lambda function, follow these steps:

1. Go to the AWS Management Console.
2. Click on the “Lambda” service.
3. Click the “Create function” button.
4. Choose the “Author from scratch” option.
5. Give your function a name and select the “Ruby” runtime.
6. Choose or create an IAM role for your Lambda function. This role defines what permissions your function will have within your AWS account.
7. Click the “Create function” button.

Step 2: Write the code for your Lambda function

In the function code editor, you can now write the code for your Lambda function in Ruby. Here’s a simple example that takes in an event and returns a response:

def lambda_handler(event:, context:)
  name = event['name'] || 'stranger'
  response = "Hello, #{name}!"
  { statusCode: 200, body: response }
end

Save your changes and then test your function by clicking the “Test” button and providing a sample event. You can also view the logs for your function to see the results of your test.

Step 3: Interact with other AWS services from within your function

You can use the AWS SDK for Ruby to interact with other AWS services, like S3 or DynamoDB, from within your Lambda function. Here’s a simple example that reads data from an S3 bucket and returns it as the response:

require 'aws-sdk-s3'

def lambda_handler(event:, context:)
  s3 = Aws::S3::Client.new
  obj = s3.get_object(bucket: 'my-bucket', key: 'my-file.txt')
  response = obj.body.read
  { statusCode: 200, body: response }
end

In this example, we use the aws-sdk-s3 gem to interact with the S3 service and retrieve the contents of a file in a bucket.

Conclusion

AWS Lambda makes it easy to build and run applications and services without having to manage any infrastructure. With the ability to write your Lambda functions in Ruby, you can use this powerful platform to build a wide range of applications, from simple event-driven scripts to complex, multi-tier systems. Whether you’re new to serverless computing or a seasoned professional, AWS Lambda is a great platform for building and running your next project.