app.py

#!bin/python3

from flask import Flask
from redis import Redis, RedisError
import os
import socket

redis = Redis(host='redis', db=0, socket_connect_timeout=2, socket_timeout=2)

app = Flask(__name__)


@app.route('/')
def hello():
    try:
        visits = redis.incr('counter')
    except RedisError:
        visits = '<i>cannot connect to Redis, counter disabled</i>'

    html = '<h3>Hello {name}!</h3>' \
        '<b>Hostname:</b> {hostname}' \
        '<b>Visits:</b> {visits}'

    return html.format(
        name=os.getenv('NAME', 'world'),
        hostname=socket.gethostname(),
        visits=visits
    )


if __name__ == '__main__':
    app.run(host='0.0.0.0', port=80)