readFileSync from an URL for Twitter media - node.js

Question

I need to use an URL to import a media to Twitter. But I can't figure out how to use an URL without having to download the image, save it temporarily on the server and deleted after...

I'm using Google Cloud to store the images that's why I can't access it directly.

That's what I'm trying to do :

var data = require('fs').readFileSync('https://www.example.com/image.png');

//Create the Twitter client
const client = new Twitter({
  consumer_key: process.env.consumer_key_dev,
  consumer_secret: process.env.consumer_secret_dev,
  access_token_key: user.val().access.token,
  access_token_secret: user.val().access.secret
});

// Make post request on media endpoint. Pass file data as media parameter
return client.post('media/upload', {media: data}, function(error, media, response) {

  if (!error) {

    // If successful, a media object will be returned.
    console.log(media);

    // Lets tweet it
    var status = {
      status: sendTweet,
      media_ids: media.media_id_string // Pass the media id string
    }

    return client.post('statuses/update', status, function(error, tweet, response) {
      if (!error) {
        console.log(tweet);
      }
    });

  }
});

But I get this error :

ERROR: { Error: ENOENT: no such file or directory, open 'https://storage.googleapis.com/...

Any idea on how I should do it?

Answer 1

The problem you have here is that trying you're using the 'File System (fs)' module to access a location not in your file system.

You would solve the getting of the image using the 'http' or 'https' modules. An example of usage would be:

const https = require('https');

function getImage(url, callback) {
    https.get(url, res => {
        // Initialise an array
        const bufs = [];

        // Add the data to the buffer collection
        res.on('data', function (chunk) {
            bufs.push(chunk)
        });

        // This signifies the end of a request
        res.on('end', function () {
            // We can join all of the 'chunks' of the image together
            const data = Buffer.concat(bufs);

            // Then we can call our callback.
            callback(null, data);
        });
    })
    // Inform the callback of the error.
    .on('error', callback);
}

// Then you 'get' your image like so:
getImage('https://www.example.com/image.png', function (err, data) {
    // Handle the error if there was an error getting the image.
    if (err) {
        throw new Error(err);
    }

    // Now you can use the rest of your code here:
    const client = new Twitter({ ... });
    // etc.
    // I've removed the rest because of size.
    return client.post(
        'media/upload',
        {media: data},
        function(error, media, response) {
            // ...
        }
    );
})

You cannot do http requests synchronously, and I strongly advise you try to avoid synchronous requests because of blocking (https://nodejs.org/en/docs/guides/blocking-vs-non-blocking/).