AWS API Gateway Responses via serverless framework - amazon-web-services

Question

I'd like to be able to configure API Gateway Responses via serverless framework...
This is what my serverless.yml looks like:
#Deploy an api gateway with custom responses.
---
service: test-apigw
frameworkVersion: ">=3.20"
provider:
name: aws
stage: dev
region: us-east-1
stackName: ${self:service}
apiName: test-apigw
endpointType: REGIONAL
functions:
hello:
handler: handler.endpoint
events:
- http:
path: /hello-world
method: ANY
private: true
package:
individually: true
excludeDevDependencies: false
Now I read somewhere that one can configure resources in a serverless file, however by using CFN code I'd need the ARN or the Ref of an already deployed API Gateway or, declare the API Gateway with CFN code (which I want to avoid)...
Is there a way to configure these Gateway Responses (not integration responses!!) using the same api gateway that my serverless.yml is deploying? i.e. the one with name test-apigw?

Answer 1

It turns out the response I quoted actually works for me.
In the same serverless.yml file, put the GatewayResponses you want to configure.
resources:
Resources:
Unauthorized:
Type: "AWS::ApiGateway::GatewayResponse"
Properties:
ResponseParameters:
gatewayresponse.header.Access-Control-Allow-Origin: "'*'"
gatewayresponse.header.Access-Control-Allow-Headers: "'*'"
ResponseTemplates:
"application/json": ${file(gateway-responses/responses.js):unauthorized}
ResponseType: UNAUTHORIZED
RestApiId: !Ref ApiGatewayRestApi
StatusCode: '401'
At least for version 3.20 of serverless framework, the created API name is ApiGatewayRestApi, this will only work of course, if you're only creating one API Gw in that file and I believe, the API Gateway has to be already deployed.
The correct way to do this is, as the official serverless documentation states, to create the API Gateway with Cloudformation code.