Event notification listener for OpenStack

openstackEvents.py

########################################
#    Required changes to nova.conf     #
########################################
# notification_driver=nova.openstack.common.notifier.rpc_notifier
# notification_topics = notifications
# notify_on_state_change = vm_and_task_state
# instance_usage_audit_period = hour
# instance_usage_audit = True
# default_notification_level = INFO
# notify_api_faults = true
###### Restart Nova services after making the above changes #######

# Environment Variables: $AMQP_USER, $AMQP_PASSWORD, $AMQP_HOST
import os
from kombu import Connection, Exchange, Queue
from pprint import pprint

nova_x = Exchange('nova', type='topic', durable=False)
info_q = Queue('notifications.info', exchange=nova_x, durable=False, 
               routing_key='notifications.info')

def process_msg(body, message):
    print '='*80
    pprint(body)
    message.ack()

# Maybe wrap these in try/except: will raise KeyError if not found
AMQP_USER = os.environ['AMQP_USER']
AMQP_PASSWORD = os.environ['AMQP_PASSWORD']
AMQP_HOST = os.environ['AMQP_HOST']


# Maybe wrap this in a try/except: will raise socket.error if connection refused
with Connection('amqp://{0}:{1}@{2}//'.format(AMQP_USER, AMQP_PASSWORD, AMQP_HOST)) as conn:
    with conn.Consumer(info_q, callbacks=[process_msg]):
        try:
            while True:
                conn.drain_events()
        except KeyboardInterrupt:
            exit()

I also made a slightly modified version of the script in this gist which is much less verbose, which I used to correlate event start/end times:

#!/usr/bin/env python
########################################
#    Required changes to nova.conf     #
########################################
# notification_driver=nova.openstack.common.notifier.rpc_notifier
# notification_topics = notifications
# notify_on_state_change = vm_and_task_state
# instance_usage_audit_period = hour
# instance_usage_audit = True
# default_notification_level = INFO
# notify_api_faults = true
###### Make sure you restart Nova#######

from kombu import Connection, Exchange, Queue
from pprint import pprint

nova_x = Exchange('nova', type='topic', durable=False)
info_q = Queue('notifications.info', exchange=nova_x, durable=False,
               routing_key='notifications.info')

def process_msg(body, message):
    print '='*80
    print body['event_type']
    print body['publisher_id']
    print body['timestamp']
    #pprint(body)
    message.ack()

#Change guest:guest and the hostname to match your configuration
with Connection('amqp://guest:guest@localhost//') as conn:
    with conn.Consumer(info_q, callbacks=[process_msg]):
        try:
            while True:
                conn.drain_events()
        except KeyboardInterrupt:
            exit()

which produces output like:

compute.instance.exists
compute.devstack
2015-12-08 19:00:12.966361
================================================================================
floatingip.update.start
network.devstack
2015-12-08 19:35:23.684770
================================================================================

Well 2. is not an assumption you can make about all hosts running Nova. People will install nova and dependencies into virtual environments and wherever else they like if they don't want to interfere with their system python. I would suggest you drop the shebang and suggest people run it like </path/to/nova/env/>bin/python openstack_events.py. You can probably trust people to know where this directory is. If not, then maybe: wrap this in a PyPi package that ships kombu as a separate dependency OR write a bash script that creates a virtualenv, installs kombu, runs venv/bin/python openstackEvents.py

Made the changes to environment variables.
I think the bash script option is best. I quickly wrote one here: https://gist.github.com/vagelim/98c8792ba12dc8f90341
@talwai

Hello,
I had to replace routing_key='notifications.info' by routing_key='notifications.*' since I was not catching some nova messages like instance.create.{start,end} amongst others.