ws_redis_prod

# producer.py
# https://yeti.co/blog/establishing-a-websocket-pubsub-server-with-redis-and-asyncio-for-the-light-sensor/

import asyncio
from aioredis import create_connection, Channel
import websockets

async def subscribe_to_redis(path):
    conn = await create_connection(('localhost', 6379))

    # Set up a subscribe channel
    channel = Channel('lightlevel{}'.format(path), is_pattern=False)
    await conn.execute_pubsub('subscribe', channel)
    return channel, conn

async def consumer_handler(websocket, path):
    pass  # process websocket data

async def producer_handler(websocket, path):
    channel, conn = await subscribe_to_redis(path)
    try:
        while True:
            # Wait until data is published to this channel
            message = await channel.get()

            # Send unicode decoded data over to the websocket client
            await websocket.send(message.decode('utf-8'))

    except websockets.exceptions.ConnectionClosed:
        # Free up channel if websocket goes down
        await conn.execute_pubsub('unsubscribe', channel)
        conn.close()
        
async def handler(websocket, path):
    consumer_task = asyncio.ensure_future(
        consumer_handler(websocket, path))
    producer_task = asyncio.ensure_future(
        producer_handler(websocket, path))
    done, pending = await asyncio.wait(
        [consumer_task, producer_task],
        return_when=asyncio.FIRST_COMPLETED,
    )
    for task in pending:
        task.cancel()
        
if __name__ == '__main__':
    # Runs a server process on 8767. Just do 'python producer.py'
    loop = asyncio.get_event_loop()
    loop.set_debug(True)
    ws_server = websockets.serve(handler, 'localhost', 8767)
    loop.run_until_complete(ws_server)
    loop.run_forever()