Flask Cache S3 Objects with Redis

flask_cache_redis_s3.py

from StringIO import StringIO

from flask import send_file, Flask
import requests
import redis

app = Flask(__name__)
redis_server = redis.StrictRedis(host='localhost', port=6379)

@app.route('/img/<server>/<hash_string>')
def image(server, hash_string):
    """Handle image, use redis to cache image."""
    image_url = 'https://objects-us-east-1.dream.io/foobar/assets/images/aws-logo.png?AWSAccessKeyId=somekey&Expires=5436864673&Signature=somesignature'
    cached = redis_server.get(image_url)
    if cached:
        buffer_image = StringIO(cached)
        buffer_image.seek(0)
    else:
        r = requests.get(image_url)
        buffer_image = StringIO(r.content)
        buffer_image.seek(0)
        redis_server.setex(image_url, (60*60*24*7),
                           buffer_image.getvalue())
    return send_file(buffer_image, mimetype='image/jpeg')

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=80)
    
# thanks:
# https://stackoverflow.com/questions/30240370/python-flask-image-proxy