AWS API Gateway - HTTP Passthrough Path Parameters - amazon-web-services

Question

I'm trying out the HTTP passthrough functionality in API gateway, passing through a resource method to another API. I want to pass through the path parameters from the API gateway URL to the backend API that also needs those path parameters.
I have the following simple Swagger document trying to test this out:
{
"swagger": "2.0",
"info": {
"version": "2017-09-15T03:33:48Z",
"title": "api-gateway-http-test"
},
"schemes": [
"https"
],
"paths": {
"/subresource/{name}": {
"get": {
"produces": [
"application/json"
],
"responses": {
"200": {
"description": "200 response",
"schema": {
"$ref": "#/definitions/Empty"
}
}
},
"x-amazon-apigateway-integration": {
"uri": "http://my.web.service.url/subresource/{name}",
"passthroughBehavior": "when_no_match",
"httpMethod": "GET",
"type": "http_proxy",
"requestParameters": {
"integration.request.path.name": "method.request.path.name"
}
}
}
}
},
"definitions": {
"Empty": {
"type": "object",
"title": "Empty Schema"
}
}
}
When I try deploying this to API Gateway via CloudFormation, API Gateway gives me this error:
Unable to put integration on 'GET' for resource at path '/subresource/{name}':
Invalid mapping expression specified:
Validation Result:
warnings : [], errors : [Invalid mapping expression parameter specified: method.request.path.name]
I've looked at various sources online, and this way of configuring the "requestParameters" section seems to be the recommended way to pass through path parameters to the backend API.
What am I missing here that would cause this to not work?

Answer 1

It is missing parameter definitions.
Check it out with the below,
{
"swagger": "2.0",
"info": {
"version": "2017-09-15T03:33:48Z",
"title": "api-gateway-http-test"
},
"schemes": [
"https"
],
"paths": {
"/subresource/{name}": {
"get": {
"produces": [
"application/json"
],
"parameters": [
{
"name": "name",
"in": "path",
"required": true,
"type": "string"
}
],
"responses": {
"200": {
"description": "200 response",
"schema": {
"$ref": "#/definitions/Empty"
}
}
},
"x-amazon-apigateway-integration": {
"uri": "http://google.com/subresource/{name}",
"passthroughBehavior": "when_no_match",
"httpMethod": "GET",
"type": "http_proxy",
"requestParameters": {
"integration.request.path.name": "method.request.path.name"
}
}
}
}
},
"definitions": {
"Empty": {
"type": "object",
"title": "Empty Schema"
}
}
}