Upload image available at public URL to S3 using boto

Question

I'm working in a Python web environment and I can simply upload a file from the filesystem to S3 using boto's key.set_contents_from_filename(path/to/file). However, I'd like to upload an image that is already on the web (say https://pbs.twimg.com/media/A9h_htACIAAaCf6.jpg:large).

Should I somehow download the image to the filesystem, and then upload it to S3 using boto as usual, then delete the image?

What would be ideal is if there is a way to get boto's key.set_contents_from_file or some other command that would accept a URL and nicely stream the image to S3 without having to explicitly download a file copy to my server.

def upload(url):
    try:
        conn = boto.connect_s3(settings.AWS_ACCESS_KEY_ID, settings.AWS_SECRET_ACCESS_KEY)
        bucket_name = settings.AWS_STORAGE_BUCKET_NAME
        bucket = conn.get_bucket(bucket_name)
        k = Key(bucket)
        k.key = "test"
        k.set_contents_from_file(url)
        k.make_public()
                return "Success?"
    except Exception, e:
            return e

Using set_contents_from_file, as above, I get a "string object has no attribute 'tell'" error. Using set_contents_from_filename with the url, I get a No such file or directory error . The boto storage documentation leaves off at uploading local files and does not mention uploading files stored remotely.

Answer 1

Ok, from @garnaat, it doesn't sound like S3 currently allows uploads by url. I managed to upload remote images to S3 by reading them into memory only. This works.

def upload(url):
    try:
        conn = boto.connect_s3(settings.AWS_ACCESS_KEY_ID, settings.AWS_SECRET_ACCESS_KEY)
        bucket_name = settings.AWS_STORAGE_BUCKET_NAME
        bucket = conn.get_bucket(bucket_name)
        k = Key(bucket)
        k.key = url.split('/')[::-1][0]    # In my situation, ids at the end are unique
        file_object = urllib2.urlopen(url)           # 'Like' a file object
        fp = StringIO.StringIO(file_object.read())   # Wrap object    
        k.set_contents_from_file(fp)
        return "Success"
    except Exception, e:
        return e

Also thanks to How can I create a GzipFile instance from the “file-like object” that urllib.urlopen() returns?