Q:

Meteor Fiber issue with callback in knox

I'm having difficulty understanding where exactly I should implement wrapAsync/bindEnvironment in the code I'm working on. I am making a call to a url with http/knox and uploading it to my S3 bucket which works, but when I try to call the function in the callback, I get hit with a Meteor code must always run within a Fiber. 
I tried to wrap the callback in bindEnvironment and attempted to use wrapAsync, but must have not understood exactly how this works. Any guidance will be greatly appreciated!
http.get(imageUrl, function(res) {
  let headers = {
    'Content-Length': res.headers['content-length']
    , 'Content-Type': res.headers['content-type']
  };
  S3.knox.putStream(res, `/${imageName}`, headers, function(err, res) {
    if (err) {
      log.error(`(imageUpload): Error uploading image with knox: ${err}`);
    } else {
      let amazonImagePath = `https://s3.amazonaws.com/${bucketName}/${imageName}`;
      // TODO Figure out why fiber issue is happening with expenseInsert in callback
      expenseInsert(expenseObj, amazonImagePath);
    }
  });
});

A:

Try this:
S3.knox.putStream(res, `/${imageName}`, headers, Meteor.bindEnvironment(function(err, res) {
    //rest of the code    
}));

