AIL-framework/bin/Helper.py

#!/usr/bin/env python2
# -*-coding:UTF-8 -*
"""
Queue helper module
============================

This module subscribe to a Publisher stream and put the received messages
into a Redis-list waiting to be popped later by others scripts.

..note:: Module ZMQ_Something_Q and ZMQ_Something are closely bound, always put
the same Subscriber name in both of them.

"""
import redis
try: # dirty to support python3
    import ConfigParser
except:
    import configparser
    ConfigParser = configparser
import os
import zmq
import time
import datetime
import json


class PubSub(object):

    def __init__(self):
        configfile = os.path.join(os.environ['AIL_BIN'], 'packages/config.cfg')
        if not os.path.exists(configfile):
            raise Exception('Unable to find the configuration file. \
                            Did you set environment variables? \
                            Or activate the virtualenv.')
        self.config = ConfigParser.ConfigParser()
        self.config.read(configfile)
        self.redis_sub = False
        self.zmq_sub = False
        self.subscribers = None
        self.publishers = {'Redis': [], 'ZMQ': []}

    def setup_subscribe(self, conn_name):
        if self.config.has_section(conn_name):
            channel = self.config.get(conn_name, 'channel')
        else:
            channel = conn_name.split('_')[1]
        if conn_name.startswith('Redis'):
            self.redis_sub = True
            r = redis.StrictRedis(
                host=self.config.get('RedisPubSub', 'host'),
                port=self.config.get('RedisPubSub', 'port'),
                db=self.config.get('RedisPubSub', 'db'))
            self.subscribers = r.pubsub(ignore_subscribe_messages=True)
            self.subscribers.psubscribe(channel)
        elif conn_name.startswith('ZMQ'):
            self.zmq_sub = True
            context = zmq.Context()

            self.subscribers = []
            addresses = self.config.get(conn_name, 'address')
            for address in addresses.split(','):
                new_sub = context.socket(zmq.SUB)
                new_sub.connect(address)
                new_sub.setsockopt(zmq.SUBSCRIBE, channel)
                self.subscribers.append(new_sub)

    def setup_publish(self, conn_name):
        if self.config.has_section(conn_name):
            channel = self.config.get(conn_name, 'channel')
        else:
            channel = conn_name.split('_')[1]
        if conn_name.startswith('Redis'):
            r = redis.StrictRedis(host=self.config.get('RedisPubSub', 'host'),
                                  port=self.config.get('RedisPubSub', 'port'),
                                  db=self.config.get('RedisPubSub', 'db'))
            self.publishers['Redis'].append((r, channel))
        elif conn_name.startswith('ZMQ'):
            context = zmq.Context()
            p = context.socket(zmq.PUB)
            p.bind(self.config.get(conn_name, 'address'))
            self.publishers['ZMQ'].append((p, channel))

    def publish(self, message):
        m = json.loads(message)
        channel_message = m.get('channel')
        for p, channel in self.publishers['Redis']:
            if channel_message is None or channel_message == channel:
                p.publish(channel, m['message'])
        for p, channel in self.publishers['ZMQ']:
            if channel_message is None or channel_message == channel:
                p.send('{} {}'.format(channel, m['message']))

    def subscribe(self):
        if self.redis_sub:
            for msg in self.subscribers.listen():
                if msg.get('data', None) is not None:
                    yield msg['data']
        elif self.zmq_sub:
            while True:
                for sub in self.subscribers:
                    try:
                        msg = sub.recv(zmq.NOBLOCK)
                        yield msg.split(' ', 1)[1]
                    except zmq.error.Again as e:
                        time.sleep(0.2)
                        pass
        else:
            raise Exception('No subscribe function defined')


class Process(object):

    def __init__(self, conf_section):
        configfile = os.path.join(os.environ['AIL_BIN'], 'packages/config.cfg')
        if not os.path.exists(configfile):
            raise Exception('Unable to find the configuration file. \
                            Did you set environment variables? \
                            Or activate the virtualenv.')
        modulesfile = os.path.join(os.environ['AIL_BIN'], 'packages/modules.cfg')
        self.config = ConfigParser.ConfigParser()
        self.config.read(configfile)
        self.modules = ConfigParser.ConfigParser()
        self.modules.read(modulesfile)
        self.subscriber_name = conf_section

        self.pubsub = None
        if self.modules.has_section(conf_section):
            self.pubsub = PubSub()
        else:
            raise Exception('Your process has to listen to at least one feed.')
        self.r_temp = redis.StrictRedis(
            host=self.config.get('RedisPubSub', 'host'),
            port=self.config.get('RedisPubSub', 'port'),
            db=self.config.get('RedisPubSub', 'db'))

        self.moduleNum = os.getpid()


    def populate_set_in(self):
        # monoproc
        src = self.modules.get(self.subscriber_name, 'subscribe')
        self.pubsub.setup_subscribe(src)
        for msg in self.pubsub.subscribe():
            in_set = self.subscriber_name + 'in'
            self.r_temp.sadd(in_set, msg)
            self.r_temp.hset('queues', self.subscriber_name,
                             int(self.r_temp.scard(in_set)))

    def get_from_set(self):
        # multiproc
        in_set = self.subscriber_name + 'in'
        self.r_temp.hset('queues', self.subscriber_name,
                         int(self.r_temp.scard(in_set)))
        message = self.r_temp.spop(in_set)
        timestamp = int(time.mktime(datetime.datetime.now().timetuple()))
        dir_name = os.environ['AIL_HOME']+self.config.get('Directories', 'pastes')

        if message is None:
            return None

        else:
            try:
                if ".gz" in message:
                    path = message.split(".")[-2].split("/")[-1]
                    #find start of path with AIL_HOME
                    index_s = message.find(os.environ['AIL_HOME'])
                    #Stop when .gz
                    index_e = message.find(".gz")+3 
                    complete_path = message[index_s:index_e]

                else:
                    path = "?"
                value = str(timestamp) + ", " + path
                self.r_temp.set("MODULE_"+self.subscriber_name + "_" + str(self.moduleNum), value)
                self.r_temp.set("MODULE_"+self.subscriber_name + "_" + str(self.moduleNum) + "_PATH", complete_path)
                self.r_temp.sadd("MODULE_TYPE_"+self.subscriber_name, str(self.moduleNum))
                return message

            except:
                path = "?"
                value = str(timestamp) + ", " + path
                self.r_temp.set("MODULE_"+self.subscriber_name + "_" + str(self.moduleNum), value)
                self.r_temp.set("MODULE_"+self.subscriber_name + "_" + str(self.moduleNum) + "_PATH", "?")
                self.r_temp.sadd("MODULE_TYPE_"+self.subscriber_name, str(self.moduleNum))
                return message

    def populate_set_out(self, msg, channel=None):
        # multiproc
        msg = {'message': msg}
        if channel is not None:
            msg.update({'channel': channel})
        self.r_temp.sadd(self.subscriber_name + 'out', json.dumps(msg))

    def publish(self):
        # monoproc
        if not self.modules.has_option(self.subscriber_name, 'publish'):
            return False
        dest = self.modules.get(self.subscriber_name, 'publish')
        # We can have multiple publisher
        for name in dest.split(','):
            self.pubsub.setup_publish(name)
        while True:
            message = self.r_temp.spop(self.subscriber_name + 'out')
            if message is None:
                time.sleep(1)
                continue
            self.pubsub.publish(message)