ApiGateway CloudFormation without lambda - amazon-web-services

Question

I am trying to create a template so that when i call api/divide/inputvalue, The api sends back response from DynamoDB which corresponds to inputvalue mapping.
Its pretty straight forward since i am fetching value directly from db without any business logic hence I don't need any lambda. But all the examples that I google or all tutorials they are using lambdas and i am now lost that how can i make it working without lambda
This is what I have so far. There is bug in this template right now since I haven't provided Uri in ApiGateway::Method. Which is what I am currently stuck at.
{
"AWSTemplateFormatVersion": "2010-09-09",
"Resources": {
"Deployment": {
"Type": "AWS::ApiGateway::Deployment",
"Properties": {
"RestApiId": { "Ref": "restApiName" },
"Description": "First Deployment",
"StageName": "StagingStage"
},
"DependsOn" : ["restApiMethod"]
},
"restApiMethod": {
"Type": "AWS::ApiGateway::Method",
"Properties": {
"AuthorizationType": "NONE",
"HttpMethod": "GET",
"ResourceId": {"Ref": "apiRestResource"},
"RestApiId": {"Ref": "restApiName"},
"Integration": {
"Type": "AWS",
"IntegrationHttpMethod": "GET",
"IntegrationResponses": [{"StatusCode": 200}],
"Uri": { "Fn::Sub":"arn.aws.apigateway:${AWS::Region}:dynamodb:action/${restApiName.Arn}"}
},
"MethodResponses": [{"StatusCode": 200}]
},
"DependsOn": ["apiRestResource"]
},
"apiRestResource": {
"Type": "AWS::ApiGateway::Resource",
"Properties": {
"RestApiId": {"Ref": "restApiName"},
"ParentId": {
"Fn::GetAtt": ["restApiName","RootResourceId"]
},
"PathPart": "divide"
},
"DependsOn": ["restApiName"]
},
"restApiName": {
"Type": "AWS::ApiGateway::RestApi",
"Properties": {
"Name": "CalculationApi"
}
}
}
}

Answer 1

According to the documentation, the Uri property is structured as follows for AWS service-proxy integration types:
If you specify AWS for the Type property, specify an AWS service that follows the form: arn:aws:apigateway:region:subdomain.service|service:path|action/service_api. For example, a Lambda function URI follows the form: arn:aws:apigateway:region:lambda:path/path. The path is usually in the form /2015-03-31/functions/LambdaFunctionARN/invocations. For more information, see the uri property of the Integration resource in the Amazon API Gateway REST API Reference.
The uri API Gateway property reference provides more details:
For AWS integrations, the URI should be of the form arn:aws:apigateway:{region}:{subdomain.service|service}:{path|action}/{service_api}. Region, subdomain and service are used to determine the right endpoint. For AWS services that use the Action= query string parameter, service_api should be a valid action for the desired service. For RESTful AWS service APIs, path is used to indicate that the remaining substring in the URI should be treated as the path to the resource, including the initial /.
For an AWS service proxy to the dynamodb service calling the Query Action, the Uri should be something like this (using the YAML short-form of Fn::Sub to insert a Ref for the current AWS region):
!Sub "arn:aws:apigateway:${AWS::Region}:dynamodb:action/Query"
As for your broader use-case of using API Gateway to access DynamoDB without using Lambda functions, refer to Andrew Baird's tutorial blog post, "Using Amazon API Gateway as a Proxy for DynamoDB", and translate the specified Management Console steps to corresponding CloudFormation template resources.