Express lambda return JSON from api call

Question

I have a serverless express app. In the app I have a app.get called '/', which should call an api, retrieve the data from the api and send it back to the user.

https://y31q4zn654.execute-api.eu-west-1.amazonaws.com/dev

I can see data as json on the page being returned.

This is my index.js of the lambda function:

const serverless = require('serverless-http');
const express = require('express');
const request = require('request');
const app = express()

app.get('/', function (req, res) {

  var options = { method: 'POST',
   url: 'https://some.api.domain/getTopNstc',
   headers:
    {   'Content-Type': 'application/json' },
   body: {},
   json: true
  };

  request(options, function (error, response, body) {
    console.log('request call')
   if (error) throw new Error(error);
  // res.status(200).send(response);
  res.json(response);
  });
});

module.exports.handler = serverless(app);

However I would to be able to call the lambda '/' via axios (or other promise-request library)

I've tried to use the following code to make a call to my lambda:

axios.get('https://y31q4zn654.execute-api.eu-west-1.amazonaws.com/dev', {
  headers: {
    'Content-Type': 'application/json',
   },
  body:{}
  }).then((res) => {
  console.log(res);
 });

Failed to load https://y31q4zn654.execute-api.eu-west-1.amazonaws.com/dev: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'myDomain' is therefore not allowed access. bundle.js:31 Cross-Origin Read Blocking (CORB) blocked cross-origin response https://y31q4zn654.execute-api.eu-west-1.amazonaws.com/dev with MIME type application/json. See https://www.chromestatus.com/feature/5629709824032768 for more details.

Api gateway config:

Answer 1

I concur with @KMo. Pretty sure this is a CORS issue. There is a module in npm exactly for this purpose, read up about it here.

To install it, run npm install -s cors

Then in your express app, add the following:

const express = require('express'); const app = express(); const cors = require('cors'); app.use(cors());