Applying DevOps to AWS Lambda Applications

Let's briefly look at what we learned about AWS Lambda functions. Amazon Web Services was the first web service platform to launch the serverless computing module Lambda, written in Lambda functions. Lambda functions are stateless and have no affinity with the underlying infrastructure. Lambda functions are executed in response to the events. These events could be an HTTP request, a change of the data in the S3 bucket, a change in a DynamoDB table, or a change in Kinesis or SNS. Lambda functions replicate faster in response to events, and descale as the number of events goes down. 

In this chapter, we will be covering various methods of deploying Lambda functions, looking at how we can painlessly deploy to multiple environments, unit test, system test, and integration test the Lambda function. We will also learn various deployment best practices and go through a few example recipes using these best practices. We will see how we can manage the AWS Lambda logs and move them to the ELK stack. 

We will explore the following topics in this chapter:

• Manual deployment of a Lambda function
• AWS Lambda with DevOps
• Serverless with CodeStar
• Blue and green deployment with AWS Lambda
• The GitHub and Jenkins pipeline using Serverless Framework
• Setting up Jenkins for a serverless application
• Unit testing a deployed application
• Integrating CloudWatch with ELK

I will be creating a simple application that is used in our day-to-day work. The application is a thumbnail creator, and is a Node.js application that uses two S3 buckets. One bucket is for uploading the actual images and the other is for the thumbnails. The moment an image is uploaded into the images bucket, an event is triggered that calls a function to resize the image and upload it to the thumbnails bucket. We will first look at how we can manually execute this sequence of events, and then we will learn how we can streamline the process by automating the deployment process. In the section dealing with DevOps, we will talk about setting up an assembly line with the development environment, automated testing and deployment, applying a CI/CD pipeline, logging, and monitoring.