import logging
import redis  # http://pypi.python.org/pypi/redis


class RedisHandler(logging.Handler):
    def __init__(self, lname, conn, *args, **kwargs):
        logging.Handler.__init__(self, *args, **kwargs)
        self.lname = lname
        self.channel = lname + ":chan"
        self.redis_conn = conn

    def emit(self, record):
        msg = self.format(record)
        try:
            self.redis_conn.pipeline()\
                .publish(self.channel, msg)\
                .rpush(self.lname, msg)\
                .ltrim(self.lname, -1000, -1)\  # keep only the last 1000 log entries
                .execute()
        except redis.RedisError:
            pass


# Usage example

if __name__ == '__main__':

    import socket

    host = socket.gethostname().split('.')[0]
    fmt = '%(asctime)s  {0}  %(name)s  %(levelname)s  %(message)s'.format(host)
    logging.basicConfig(format=fmt, level=logging.INFO)
    logger = logging.getLogger(__name__)
    handler = RedisHandler('foolog', redis.StrictRedis('redis.example.com'))
    handler.setFormatter(logging.Formatter(fmt))
    logger.addHandler(handler)
    logger.info('Logger set up.')