planetstack/ec2_observer/event_manager.py

import threading
import requests, json

from planetstack.config import Config

import uuid
import os
import imp
import inspect
import base64
from fofum import Fofum
import json
import traceback

random_client_id=None
def get_random_client_id():
    global random_client_id

    if (random_client_id is None) and os.path.exists("/opt/planetstack/random_client_id"):
        # try to use the last one we used, if we saved it
        try:
            random_client_id = open("/opt/planetstack/random_client_id","r").readline().strip()
            print "get_random_client_id: loaded %s" % random_client_id
        except:
            print "get_random_client_id: failed to read /opt/planetstack/random_client_id"

    if random_client_id is None:
        random_client_id = base64.urlsafe_b64encode(os.urandom(12))
        print "get_random_client_id: generated new id %s" % random_client_id

        # try to save it for later (XXX: could race with another client here)
        try:
            open("/opt/planetstack/random_client_id","w").write("%s\n" % random_client_id)
        except:
            print "get_random_client_id: failed to write /opt/planetstack/random_client_id"

    return random_client_id

# decorator that marks dispatachable event methods
def event(func):
    setattr(func, 'event', func.__name__)
    return func

class EventHandler:
    # This code is currently not in use.
    def __init__(self):
        pass

    @staticmethod
    def get_events():
        events = []
        for name in dir(EventHandler):
            attribute = getattr(EventHandler, name)
            if hasattr(attribute, 'event'):
                events.append(getattr(attribute, 'event'))
        return events

    def dispatch(self, event, *args, **kwds):
        if hasattr(self, event):
            return getattr(self, event)(*args, **kwds)
            

class EventSender:
    def __init__(self,user=None,clientid=None):
        try:
            user = Config().feefie_client_user
        except:
            user = 'pl'

        try:
            clid = Config().feefie_client_id
        except:
            clid = get_random_client_id()
            print "EventSender: no feefie_client_id configured. Using random id %s" % clid

        self.fofum = Fofum(user=user)
        self.fofum.make(clid)

    def fire(self,**kwargs):
        kwargs["uuid"] = str(uuid.uuid1())
        self.fofum.fire(json.dumps(kwargs))

class EventListener:
    def __init__(self,wake_up=None):
        self.handler = EventHandler()
        self.wake_up = wake_up

    def handle_event(self, payload):
        payload_dict = json.loads(payload)

        if (self.wake_up):
            self.wake_up()

    def run(self):
        # This is our unique client id, to be used when firing and receiving events
        # It needs to be generated once and placed in the config file

        try:
            user = Config().feefie_client_user
        except:
            user = 'pl'

        try:
            clid = Config().feefie_client_id
        except:
            clid = get_random_client_id()
            print "EventListener: no feefie_client_id configured. Using random id %s" % clid

        f = Fofum(user=user)
        
        listener_thread = threading.Thread(target=f.listen_for_event,args=(clid,self.handle_event))
        listener_thread.start()