AWS Cloud Formation template fails with Invalid mapping expression parameter specified - amazon-web-services

Question

I am working on an AWS Cloud Formation template for an endpoint with a path like /user/{uid}/cart. I need to create an integration with an HTTP host. I've been attempting to map {uid} into the Integration Request URL Path Parameters like so:
"x-amazon-apigateway-integration": {
"uri": "http://${stageVariables.httpHost}/user/{uid}/cart",
"contentHandling": "CONVERT_TO_TEXT",
"timeoutInMillis": 29000,
"connectionType": "INTERNET",
"httpMethod": "PUT",
"passthroughBehavior": "WHEN_NO_MATCH",
"type": "HTTP_PROXY",
"requestParameters": {
"integration.request.path.uid" : "method.request.path.uid"
}...
I keep getting this error and I'm not sure what I'm doing wrong.
Errors found during import: Unable to put integration on 'PUT' for resource at path '/user/{uid}/cart': Invalid mapping expression specified: Validation Result: warnings : [], errors : [Invalid mapping expression parameter specified: method.request.path.uid]
Here's the full template
{
"Parameters": {
"AccessControlAllowOrigin": {
"Type": "String",
"Default": "*"
}
},
"Resources": {
"ConfigApi": {
"Type": "AWS::ApiGateway::RestApi",
"Properties": {
"Body": {
"swagger": "2.0",
"tags": [
{
"name": "users",
"description": "secure user calls"
}
],
"schemes": [
"https"
],
"paths": {
"/user/{uid}/cart": {
"parameters": [
{
"name": "uid",
"in": "path",
"description": "user id",
"required": true,
"type": "string",
"format": "uuid"
}
],
"put": {
"tags": [
"users",
"cart"
],
"summary": "When called, this endpoint completes the user cart and puts their cart into their library",
"operationId": "completeusercart",
"description": "Completes the user cart\n",
"produces": [
"application/json"
],
"responses": {
"200": {
"description": "the user identifier",
"headers": {
"Access-Control-Allow-Origin": {
"type": "string"
},
"Access-Control-Allow-Headers": {
"type": "string"
}
},
"schema": {
"type": "string"
}
}
},
"x-amazon-apigateway-integration": {
"uri": "http://${stageVariables.httpHost}/user/{uid}/cart",
"contentHandling": "CONVERT_TO_TEXT",
"timeoutInMillis": 29000,
"connectionType": "INTERNET",
"httpMethod": "PUT",
"passthroughBehavior": "WHEN_NO_MATCH",
"type": "HTTP_PROXY",
"requestParameters": {
"integration.request.path.uid" : "method.request.path.uid"
},
"responses": {
"default": {
"responseModels": {
"application/json": "Empty"
},
"responseParameters": {
"method.response.header.Access-Control-Allow-Origin": {
"Fn::Sub": "'${AccessControlAllowOrigin}'"
},
"method.response.header.Access-Control-Allow-Headers": "'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token'"
},
"statusCode": "200"
}
}
}
},
"options": {
"consumes": [
"application/json"
],
"produces": [
"application/json"
],
"responses": {
"200": {
"description": "200 response",
"schema": {
"$ref": "#/definitions/Empty"
},
"headers": {
"Access-Control-Allow-Origin": {
"type": "string"
},
"Access-Control-Allow-Methods": {
"type": "string"
},
"Access-Control-Allow-Headers": {
"type": "string"
}
}
}
},
"x-amazon-apigateway-integration": {
"httpMethod": "OPTIONS",
"passthroughBehavior": "WHEN_NO_MATCH",
"requestTemplates": {
"application/json": "{\"statusCode\": 200}"
},
"type": "MOCK",
"timeoutInMillis": 29000,
"responses": {
"2\\d{2}": {
"responseParameters": {
"method.response.header.Access-Control-Allow-Origin": {
"Fn::Sub": "'${AccessControlAllowOrigin}'"
},
"method.response.header.Access-Control-Allow-Methods": "'PUT,OPTIONS'",
"method.response.header.Access-Control-Allow-Headers": "'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token'"
},
"statusCode": "200"
},
"4\\d{2}": {
"statusCode": "403"
},
"5\\d{2}": {
"statusCode": "403"
}
}
}
}
}
},
"definitions": {
"Empty": {
"type": "object",
"title": "Empty Schema"
}
}
}
}
},
"ConfigApiStage": {
"Type": "AWS::ApiGateway::Stage",
"Properties": {
"DeploymentId": {
"Ref": "ApiDeployment"
},
"MethodSettings": [
{
"DataTraceEnabled": true,
"HttpMethod": "*",
"LoggingLevel": "INFO",
"ResourcePath": "/*"
}
],
"RestApiId": {
"Ref": "ConfigApi"
},
"Variables": {
"httpHost": "0.0.0.0"
},
"StageName": "LATEST"
}
},
"ApiDeployment": {
"Type": "AWS::ApiGateway::Deployment",
"Properties": {
"RestApiId": {
"Ref": "ConfigApi"
},
"StageName": "DummyStage"
}
}
}
}
Thanks for your help!

Answer 1

The issue was the placement of the parameters. These need to be under the PUT rather than under the path.
"paths": {
"/user/{uid}/cart": {
"put": {
"tags": [
"users",
"cart"
],
"parameters": [
{
"name": "uid",
"in": "path",
"description": "user id",
"required": true,
"type": "string",
"format": "uuid"
}
],...