API Gateway REST API with Lambda Integration

I created an API using the API Gateway console that allows a client to call Lambda functions via the Lambda integration.

Before creating the API, set up the Lambda backend by creating a Lambda function in AWS Lambda.

Create Lambda Function

• Sign in to the Lambda console
• On the AWS navigation bar, choose a region Note: Note the region where you create the Lambda function. You'll need it when you create the API.
• Choose Functions in the navigation pane.
• Choose Create function.
• Choose Author from scratch.

• Under Function code source, write your code in the inline code editor
• Choose Deploy

Create API Gateway

• Now create an API for your Lambda function by using the API Gateway console.
• Sign in to the API Gateway console
• Choose Create API. Under REST API, choose Build.

• Under Create new API, choose New API. Under Settings: For API name, enter "API name".
• Enter a description in the Description field or leave it empty. Leave Endpoint Type set to Regional.
• Choose Create API.

Create the resource as follows:

Choose the root resource (/) in the Resources tree.

• Choose Create Resource from the Actions dropdown menu.
• Leave Configure as proxy resource unchecked.
• For Resource Name, enter "resource_name".
• Leave Resource Path set to /resource_name.
• Leave Enable API Gateway CORS unchecked.
• Choose Create Resource.

The whole request is transmitted to the backend Lambda function through a proxy integration, using a catch-all ANY method that represents any HTTP method. The client specifies the actual HTTP method at run time. The ANY method enables you to utilize a single API method configuration for all available HTTP methods, including DELETE, GET, HEAD, OPTIONS, PATCH, POST, and PUT.

To set up the method, do the following:

• In the Resources list, choose /"resource_name".
• In the Actions menu, choose Create method.
• Choose ANY from the dropdown menu, and choose the checkmark icon.

• Leave the Integration type set to Lambda Function.
• Choose Use Lambda Proxy integration.
• From the Lambda Region dropdown menu, choose the region where you created the Lambda function.
• In the Lambda Function field, type any character and choose the Lambda function from the dropdown menu.
• Leave Use Default Timeout checked.
• Choose Save.
• Choose OK when prompted with Add Permission to Lambda Function.

Deploy API

Deploy the API in the API Gateway console

• Choose Deploy API from the Actions dropdown menu.

• For the Deployment stage, choose [new stage].

• For the Stage name, enter "test_stage".
• If desired, enter a Stage description.
• If desired, enter a Deployment description.
• Choose Deploy.
• Note the API's Invoke URL.