title: Sails.js File upload with Skipper to AWS S3
body: <p>I have a form where you can upload a file. I upload the file directly with skipper and it works perfectly.</p>
  
  <pre><code>req.file('file').upload({
      adapter: require('skipper-s3'),
      key: 'key',
      secret: 'secret',
      bucket: 'bucketname'
  }, function (err, uploadedFiles) {
      if (err){
          // ko
      }
      else{
          // ok
      }
  });
  </code></pre>
  
  <p>But I want to resize first and then upload the file, so:</p>
  
  <pre><code>sharp(original).resize(800).quality(90).toBuffer(function(err, outputBuffer) {
      if (err) {
          // ko
      }
      // ok
      outputBuffer;
   });
  </code></pre>
  
  <p>So, my question is: How can upload the <code>outputBuffer</code> instead of <code>req.file('file')</code> ?</p>