在 Google Compute Engine 上启用 Cors

Question

I'm deploying a node.js API, and a website on Google Compute Engine, every thing works fine on my local machine, also they both work well separately, but whenever i call my API i receive the following:

Access to XMLHttpRequest at 'my-api-domain' from origin 'my-website-domain' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

i use express and i use cors middleware to handle CORS, and it works on my machine, but it seems google disable this kind of response headers.

my express setup

const express = require('express')
const bodyParser = require('body-parser')
const user = require('../routes/user')
const cors = require('cors')

module.exports = function(app) {
    app.use(cors())
    app.use(express.json())
    app.use( bodyParser.json())
    app.use(bodyParser.urlencoded({
        extended: true
    }))
}

Note: I tried to send a get request to the api from the browser and it works and i recieve access-control-allow-origin: * in the response headers!

but when i call the same endpoint from the websites's origin these headers are not being sent.

Answer 1

• The error message is related to CORS and it shows that the process was not complete when a browser makes a simple request to Cloud Storage.

• Also I mentioned that to handle HTTP, Cloud Functions uses a particular HTTP framework(Express 4.16.3) in Node.js (6, 8, & 10) runtime.

If you answer the questions by guillaume blaquiere & sideshowbarker, we are able to better support.