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Olawale Adepoju for AWS Community Builders

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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.

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  • 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.

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  • 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.

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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.

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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.

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  • 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.

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Deploy API

Deploy the API in the API Gateway console

  • Choose Deploy API from the Actions dropdown menu.

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

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  • 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.

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