At AWS re:Invent 2018, it was announced that is now a supported language for AWS Lambda. In this post, I walk you through how to write your very first Ruby-based Lambda function from scratch, followed by how to configure, deploy, and test a Lambda function. Ruby will forward incoming requests to the target Ruby based Lambda function, which will call the corresponding operation on the table. API Gateway DynamoDB movies To get started, create a Lambda execution role with permission to invoke the operation on the DynamoDB table: Scan The function entry-point below is is self explanatory, it uses the AWS SDK (the package is pre-installed in Lambda) to instantiate a DynamoDB client in the appropriate region and issues the operation on the DynamoDB table (defined in an environment variable): Scan The AWS SDK for Ruby is included in the Lambda execution environment by default. Now that our handler is defined, head to the Lambda form creation and select the IAM role (you might need to refresh the page for the changes to take effect) from the drop-down list. Then, click the button: Existing role Create function Set the table name as an environment variable: The table contains a set of movies: movies Create a deployment package (zip file) and update the function’s code using the AWS CLI command: Make sure to set the Lambda function handler to handler.lambda_handler Once the function has been deployed, invoke it manually using the sample event data by clicking on the “ button in the top right of the console. Test” So far, we learned how to build our first Lambda function with Ruby. We also learned how to invoke it manually from the console. To leverage the power of Lambda, we are going to learn how to trigger this Lambda function in response to incoming HTTP requests (event-driven architecture) using the AWS API Gateway service: Create a deployment stage and open your favorite browser with the API ; you should see a message like the one shown in the following screenshot: Invoke URL The following screenshot shows a properly configured Ruby based Lambda function with IAM access to DynamoDB: Like what you’re reading? Check out my book and learn how to build, secure, deploy and manage production-ready Serverless applications in Golang with AWS Lambda. _Learn to build, secure, deploy, and manage your serverless application in Golang with AWS Lambda Key FeaturesImplement…_www.amazon.com Hands-On Serverless Applications with Go: Build real-world, production-ready applications with AWS…
