24.13. Development of REST APIs with API Gateway and Lambda: Deployment and version management of REST APIs

Developing REST APIs with API Gateway and Lambda is an increasingly common practice in the world of backend development. This is because the combination of these two tools allows for the creation of robust, scalable, and highly available APIs that can be used to power any type of web or mobile application.

API Gateway and Lambda: A powerful combination

API Gateway is an AWS-managed service that enables developers to create, publish, maintain, monitor, and secure APIs at any scale. It acts as a "gateway" for applications, handling all tasks related to accepting and processing up to hundreds of thousands of simultaneous API calls, including traffic, authorization and access control, monitoring and API management.< /p>

On the other hand, Lambda is a computing service that allows you to run code without provisioning or managing servers. It runs your code only when needed and automatically scales from a few requests per day to thousands per second. The code you run in Lambda is called a "Lambda function."

The combination of API Gateway and Lambda allows you to create REST APIs that run in Lambda functions. This means you can focus on writing your code, while AWS takes care of all the infrastructure needed to run and scale your APIs.

REST API deployment

Once you have created your REST API with API Gateway and Lambda, the next step is to deploy it. Deploying a REST API involves configuring the necessary routes, methods, integrations and authorizations so that the API can be accessed by clients.

To deploy a REST API with API Gateway and Lambda, you need to follow the following steps:

1. Create a new API in API Gateway.
2. Define the routes for your API. Each route is associated with an HTTP method (GET, POST, PUT, DELETE, etc.) and a Lambda function that will be executed when the route is called.
3. Configure integrations for each method. Integration determines how the customer request is processed and how the response is formatted.
4. If necessary, configure authorizations for your routes. This allows you to control who can call your routes.
5. Finally, deploy your API. During deployment, API Gateway creates an endpoint for your API that can be called by clients.

REST API version management

As your application grows, you will likely need to make changes to your REST API. This may include adding new routes, changing existing routes, or updating your Lambda functions. To handle these changes effectively, it is important to have a version management system.

API Gateway supports version management of REST APIs through the use of stages. A stage is a named version of your API that you can use to test and deploy changes in a controlled environment. For example, you might have a "development" stage for testing new changes, a "staging" stage for validating those changes, and a "production" stage for deploying the changes to your users.

To manage REST API versions with API Gateway and Lambda, you need to follow these steps:

1. Create a new stage for your API.
2. Deploy your changes to the new stage.
3. Test your changes on the new stage.
4. Once you are happy with your changes, promote the new stage to "production".
5. If necessary, you can roll back to a previous version of your API using the production stage.

In summary, developing REST APIs with API Gateway and Lambda is a powerful practice that allows developers to create robust and scalable APIs without having to worry about the underlying infrastructure. Additionally, API Gateway and Lambda offer deployment and version management capabilities that make it easier to maintain and evolve your APIs over time.