AWS Api Gateway proxy resource using Cloudformation? - amazon-s3

Question

I'm trying to proxy an S3 bucket configured as a website from an API Gateway endpoint. I configured an endpoint successfully using the console, but I am unable to recreate the configuration using Cloudformation.
After lots of trial and error and guessing, I've come up with the following CF stack template that gets me pretty close:
Resources:
Api:
Type: 'AWS::ApiGateway::RestApi'
Properties:
Name: ApiDocs
Resource:
Type: 'AWS::ApiGateway::Resource'
Properties:
ParentId: !GetAtt Api.RootResourceId
RestApiId: !Ref Api
PathPart: '{proxy+}'
RootMethod:
Type: 'AWS::ApiGateway::Method'
Properties:
HttpMethod: ANY
ResourceId: !GetAtt Api.RootResourceId
RestApiId: !Ref Api
AuthorizationType: NONE
Integration:
IntegrationHttpMethod: ANY
Type: HTTP_PROXY
Uri: 'http://my-bucket.s3-website-${AWS::Region}.amazonaws.com/'
PassthroughBehavior: WHEN_NO_MATCH
IntegrationResponses:
- StatusCode: 200
ProxyMethod:
Type: 'AWS::ApiGateway::Method'
Properties:
HttpMethod: ANY
ResourceId: !Ref Resource
RestApiId: !Ref Api
AuthorizationType: NONE
RequestParameters:
method.request.path.proxy: true
Integration:
CacheKeyParameters:
- 'method.request.path.proxy'
RequestParameters:
integration.request.path.proxy: 'method.request.path.proxy'
IntegrationHttpMethod: ANY
Type: HTTP_PROXY
Uri: 'http://my-bucket.s3-website-${AWS::Region}.amazonaws.com/{proxy}'
PassthroughBehavior: WHEN_NO_MATCH
IntegrationResponses:
- StatusCode: 200
Deployment:
DependsOn:
- RootMethod
- ProxyMethod
Type: 'AWS::ApiGateway::Deployment'
Properties:
RestApiId: !Ref Api
StageName: dev
Using this template I can successfully get the root of the bucket website, but the proxy resource gives me a 500:
curl -i https://abcdef.execute-api.eu-west-1.amazonaws.com/dev/index.html
HTTP/1.1 500 Internal Server Error
Content-Type: application/json
Content-Length: 36
Connection: keep-alive
Date: Mon, 11 Dec 2017 16:36:02 GMT
x-amzn-RequestId: 6014a809-de91-11e7-95e4-dda6e24d156a
X-Cache: Error from cloudfront
Via: 1.1 8f6f9aba914cc74bcbbf3c57e10df26a.cloudfront.net (CloudFront)
X-Amz-Cf-Id: TlOCX3eemHfY0aiVk9MLCp4qFzUEn5I0QUTIPkh14o6-nh7YAfUn5Q==
{"message": "Internal server error"}
I have no idea how to debug that 500.
To track down what may be wrong, I've compared the output of aws apigateway get-resource on the resource I created manually in the console (which is working) with the one Cloudformation made (which isn't). The resources look exactly alike. The output of get-method however, is subtly different, and I'm not sure it's possible to make them exactly the same using Cloudformation.
Working method configuration:
{
"apiKeyRequired": false,
"httpMethod": "ANY",
"methodIntegration": {
"integrationResponses": {
"200": {
"responseTemplates": {
"application/json": null
},
"statusCode": "200"
}
},
"passthroughBehavior": "WHEN_NO_MATCH",
"cacheKeyParameters": [
"method.request.path.proxy"
],
"requestParameters": {
"integration.request.path.proxy": "method.request.path.proxy"
},
"uri": "http://muybucket.s3-website-eu-west-1.amazonaws.com/{proxy}",
"httpMethod": "ANY",
"cacheNamespace": "abcdefg",
"type": "HTTP_PROXY"
},
"requestParameters": {
"method.request.path.proxy": true
},
"authorizationType": "NONE"
}
Configuration that doesn't work:
{
"apiKeyRequired": false,
"httpMethod": "ANY",
"methodIntegration": {
"integrationResponses": {
"200": {
"responseParameters": {},
"responseTemplates": {},
"statusCode": "200"
}
},
"passthroughBehavior": "WHEN_NO_MATCH",
"cacheKeyParameters": [
"method.request.path.proxy"
],
"requestParameters": {
"integration.request.path.proxy": "method.request.path.proxy"
},
"uri": "http://mybucket.s3-website-eu-west-1.amazonaws.com/{proxy}",
"httpMethod": "ANY",
"requestTemplates": {},
"cacheNamespace": "abcdef",
"type": "HTTP_PROXY"
},
"requestParameters": {
"method.request.path.proxy": true
},
"requestModels": {},
"authorizationType": "NONE"
}
The differences:
The working configuration has responseTemplates set to "application/json": null. As far as I can tell, there's no way to set a mapping explicitly to null using Cloudformation. My CF method instead just has an empty object here.
My CF method has "responseParameters": {},, while the working configuration does not have responseParameters at all
My CF method has "requestModels": {},, while the working configuration does not have requestModels at all
Comparing the two in the console, they are seemingly exactly the same.
I'm at my wits end here: what am I doing wrong? Is this possible to achieve using Cloudformation?

Answer 1

Answer: The above is correct. I had arrived at this solution through a series of steps, and re-applied the template over and over. Deleting the stack and deploying it anew with this configuration had the desired effect.