Using SAM application how to define body mapping templates

Question

I am new to AWS and SAM. I am developing a dummy backend using AWS services. For that, I am using SAM application to write the code locally. I defined the structure of APIs and Lambda in that as

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
    sam-app

    Sample SAM Template for sam-app

Globals:
    Function:
        Timeout: 300
    Api:
        Cors:
            AllowHeaders: "'content-type, authorization'"
            AllowOrigin: "'*'"


Resources:

    HelloWorldFunction:
        Type: AWS::Serverless::Function
        Properties:
            CodeUri: hello_world
            Handler: app.lambda_handler
            Runtime: nodejs8.10
            Environment:
                Variables:
                    PARAM1: VALUE
            Events:
                HelloWorld:
                    Type: Api
                    Properties:
                        Path: /hello2
                        Method: get

Outputs:
    HelloWorldFunction:
      Description: "Hello World Lambda Function ARN"
      Value: !GetAtt HelloWorldFunction.Arn

This creates a small dummy application. But, I want to know how to use other utilities of AWS like Body Mapping, defining model etc. Please help me know these.

Thank you...

Answer 1

You can define models, etc using an API Gateway Swagger definition. This can be embedded in the SAM template or hosted in S3 and referenced by the SAM template

Basic example looks like:

RestApi:
    Type: AWS::Serverless::Api
    Properties:
        DefinitionBody:       
            <add Swagger definition here>

See https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessapi for what the SAM API Gateway configuration options are.

Some sample SAM + API Gateway + Swagger examples are at:

• https://github.com/awslabs/serverless-application-model/blob/master/examples/2016-10-31/inline_swagger/template.yaml
• https://github.com/awslabs/serverless-application-model/blob/master/examples/2016-10-31/api_swagger_cors/template.yaml
• https://docs.aws.amazon.com/apigateway/latest/developerguide/api-as-lambda-proxy-export-swagger-with-extensions.html