Getting binary content in node.js with http.request

You need to set encoding to response, not request:

req = https.request(options, function(res) {
    res.setEncoding('binary');

    var data = [ ];

    res.on('data', function(chunk) {
        data.push(chunk);
    });
    res.on('end', function() {
        var binary = Buffer.concat(data);
        // binary is your data
    });
    res.on('error', function(err) {
        console.log("Error during HTTP request");
        console.log(err.message);
    });
});

Here is useful answer: Writing image to local server

The accepted answer did not work for me (i.e., setting encoding to binary), even the user who asked the question mentioned it did not work.

Here's what worked for me, taken from: http://chad.pantherdev.com/node-js-binary-http-streams/

http.get(url.parse('http://myserver.com:9999/package'), function(res) {
    var data = [];

    res.on('data', function(chunk) {
        data.push(chunk);
    }).on('end', function() {
        //at this point data is an array of Buffers
        //so Buffer.concat() can make us a new Buffer
        //of all of them together
        var buffer = Buffer.concat(data);
        console.log(buffer.toString('base64'));
    });
});

Edit: Update answer following a suggestion by Semicolon

1. Don't call setEncoding() method, because by default, no encoding is assigned and stream data will be returned as Buffer objects
2. Call Buffer.from() in on.data callback method to convert the chunk value to a Buffer object.

http.get('my_url', (response) => {
  const chunks = [];
  response.on('data', chunk => chunks.push(Buffer.from(chunk))) // Converte `chunk` to a `Buffer` object.
    .on('end', () => {
      const buffer = Buffer.concat(chunks);
      console.log(buffer.toString('base64'));
    });
});

Running on NodeJS 6.10(and 8.10, tested in Feb 2019) in the AWS Lambda environment, none of the solutions above worker for me.

What did work for me was the following:

https.get(opt, (res) => {
    res.setEncoding('binary');
    let chunks = [];

    res.on('data', (chunk) => {
        chunks.push(Buffer.from(chunk, 'binary'));
    });

    res.on('end', () => {
        let binary = Buffer.concat(chunks);
        // binary is now a Buffer that can be used as Uint8Array or as
        // any other TypedArray for data processing in NodeJS or 
        // passed on via the Buffer to something else.
    });
});

Take note the res.setEncoding('binary'); and Buffer.from(chunk, 'binary') lines. One sets the response encoding and the other creates a Buffer object from the string provided in the encoding specified previously.