NodeJS HTTP GET returns empty body - ajax

Question

Here's a NodeJS code snippet I'm debugging. The url is correct, and a GET request to it with Postman returns a 200 OK with the following headers. The response body is a valid JSON string.
Headers (arrows represent column divisors)
Accept-Ranges →bytes
Age →0
Cache-Control →max-age=300
Connection →keep-alive
Content-Encoding →gzip
Content-Length →255
Content-Type →application/json
Date →Tue, 24 Jan 2017 22:37:28 GMT
Expires →Tue, 24 Jan 2017 17:47:43 GMT
Last-Modified →Tue, 24 Jan 2017 01:03:08 GMT
Server →nginx
Vary →Accept-Encoding
Via →1.1 varnish
X-Cache →HIT
X-Cache-Hits →1
X-Served-By →cache-yul8926-YUL
X-Timer →S1485297448.259768,VS0,VE89
The problem:
I've discovered that res.on('data', function(chunk) { never gets called which causes body to remain empty.
When res.on('end', function() { is called body still has length = 0. Any ideas why the data callback is not getting called?
http.get(url, function(res) {
var body = '';
res.on('data', function(chunk) {
body += chunk;
});
res.on('end', function() {
var data = JSON.parse(body);
cb(data, undefined);
});
}).on('error', function(err) {
console.log("Something went wrong");
console.log(err);
});
Also worth nothing, cb is a callback function defined outside of this snippet.

Answer 1

After the lovely advice from jfriend00 I discovered that res.statusCode was 301 (Moved Permanently). Seems that the website was redirecting to the same URL but with https protocol instead of http.
When testing the REST API with Postman it did not mention the fact the request was redirected. Postman displayed a 200 OK response (???) According to the Postman Docs it will default to following redirects silently.
The solution:
I replaced all instances of http with https and it worked great.
https.get(url, function(res) {
var body = '';
res.on('data', function(chunk) {
body += chunk;
});
res.on('end', function() {
var data = JSON.parse(body);
cb(data, undefined);
});
}).on('error', function(err) {
console.log("Something went wrong");
console.log(err);
});