app.py

import time
import redis
from flask import Flask

app = Flask(__name__)
cache = redis.Redis(host='redis', port=6379)


def get_count():
    retries = 5
    while True:
        try:
            return cache.incr('hits')
        except redis.exceptions.ConnectionError as exc:
            if retries == 0:
                raise exc
            retries -= 1
            time.sleep(0.3)


@app.route('/')
def hello():
    cnt = get_count()
    return 'Hello World! cnt={}\n'.format(cnt)


if __name__ == '__main__':
    app.run(host='0.0.0.0', debug=True)