Secure "hello world" Google cloud function - google-cloud-platform

Question

I need a very secure cloud function so I'm trying to put it behind a API Gateway.
The function works fine when I call it directy passing a Bearer token in header:
https://us-central1-<my-project>.cloudfunctions.net/<my-hello-function>
However I want to allow it to be used with a API token thru API Gateway (and then do something more useful than saying "hello"):
https://my-gateway-xxxxxxxx.uc.gateway.dev/v1/stats&key=<my-API-token>
When I try to call it I get:
{
"code": 404,
"message": "Path does not match any requirement URI template."
}
My API Gateway config file:
swagger: "2.0"
info:
title: my-gateway
version: "1.0.0"
basePath: "/v1"
schemes:
- "https"
produces:
- application/json
paths:
/stats:
get:
tags:
- "stats"
summary: "get service stats"
description: "Returns statistics"
operationId: "hello_world"
#produces:
#- "application/json"
parameters:
- name: "since"
in: "header"
description: "Date to retrieve information"
required: false
type: "string"
format: "date"
x-google-backend:
address: https://us-central1-<my-project>.cloudfunctions.net/<my-hello-function>
path_translation: CONSTANT_ADDRESS
protocol: h2
responses:
"200":
description: "successful operation"
schema:
$ref: "#"
"400":
description: "Invalid datetime supplied"
"404":
description: "Unknown path"
security:
- api_key: []
securityDefinitions:
api_key:
type: "apiKey"
name: "api_key"
in: "query"
definitions:
ApiResponse:
type: "object"
properties:
code:
type: "integer"
format: "int32"
type:
type: "string"
message:
type: "string"
What's missing? What am I doing wrong?

Answer 1

I tested your file and I reviewed your HTTP call. I noticed that in your security definitions you are naming the API key as api_key but in your URL you are using the parameter key, also, it is not necessary to set path_translation: CONSTANT_ADDRESS because this is the default directive
Additionally, you can check if your gateway is using the latest configuration.
This is the config that I used and works as expected (I changed the apikey to key and I removed path_translation)
swagger: "2.0"
info:
title: my-gateway
version: "1.0.0"
basePath: "/v1"
schemes:
- "https"
produces:
- application/json
paths:
/stats:
get:
tags:
- "stats"
summary: "get service stats"
description: "Returns statistics"
operationId: "hello_world"
parameters:
- name: "since"
in: "header"
description: "Date to retrieve information"
required: false
type: "string"
format: "date"
x-google-backend:
address: https://us-central1-[myproject].cloudfunctions.net/[functionname]
protocol: h2
responses:
"200":
description: "successful operation"
schema:
$ref: "#"
"400":
description: "Invalid datetime supplied"
"404":
description: "Unknown path"
security:
- api_key: []
securityDefinitions:
api_key:
type: "apiKey"
name: "key"
in: "query"
definitions:
ApiResponse:
type: "object"
properties:
code:
type: "integer"
format: "int32"
type:
type: "string"
message:
type: "string"