Added a message queue

Added kombu, an interface to AMQP

Added react.py, sample reaction script with a kombu consumer.
Should be run separately. Just loops forever listening for
messages on the PASS_EVENTS queue/

Added queues.py, define an exchange and two queues to use
for the message queue

Replaced runthis.sh with audit.py, changed runthis.json to
audit.json. audit.py has send_message(), which sends a message
to the PASS_EVENTS queue

Configuration data for audit.py and react.py should be picked up
from audit.json and react.json.

Added H304, H302 to pep8 ignores

Change-Id: I32d5c007d3b00ee2ec33635bca1567da4447124c

entropy/audit.json

@@ -0,0 +1,11 @@
+{
+    "name" : "audit",
+    "hostname" : "localhost",
+    "cron-freq" :"*/5 * * * *",
+    "username" : "praneshp",
+    "ssh-key" : "id_rsa",
+    "mq_host": "localhost",
+    "mq_port": "5672",
+    "mq_user": "guest",
+    "mq_password": "guest"
+}

entropy/audit.py

@@ -0,0 +1,38 @@
+# Copyright (C) 2013 Yahoo! Inc. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import datetime
+
+from kombu import BrokerConnection
+from kombu.common import maybe_declare
+from kombu.pools import producers
+
+from queues import entropy_exchange
+from queues import PASS_KEY
+
+
+#TODO(praneshp) : this should be read from a conf file.
+
+
+def send_message(**kwargs):
+    connection = BrokerConnection('amqp://%(mq_user)s:%(mq_password)s@'
+                                  '%(mq_host)s:%(mq_port)s//' % kwargs)
+    message = {'From': __file__,
+               'Date': str(datetime.datetime.now())}
+    with producers[connection].acquire(block=True) as producer:
+        maybe_declare(entropy_exchange, producer.channel)
+        producer.publish(message,
+                         exchange=entropy_exchange,
+                         routing_key=PASS_KEY,
+                         serializer='json')

entropy/entropy.py

@@ -26,7 +26,11 @@ import time
 
 import croniter
 
-from entropy import utils
+sys.path.insert(0, os.path.join(os.path.abspath(os.pardir)))
+sys.path.insert(0, os.path.abspath(os.getcwd()))
+
+import audit
+import utils
 
 GOOD_MOOD = 1
 SCRIPT_REPO = os.path.dirname(__file__)
@@ -34,18 +38,22 @@ LOG_REPO = os.path.join(os.getcwd(), 'logs')
 
 
 def validate_cfg(file):
+    #TODO(praneshp): can do better here
     if GOOD_MOOD == 1:
         return True
     return False
 
 
-def do_something():
-    with open(os.path.join(os.getcwd(), 'test'), "a") as op:
-        op.write('starting audit ' + str(datetime.datetime.now()) + '\n')
+def do_something(**kwargs):
+    # Put a message on the mq
+    audit.send_message(**kwargs)
 
 
 def start_audit(**kwargs):
-    #TODO(praneshp): Start croniter job here
+    #TODO(praneshp): fix bug here, where thread wakes up 0.0003 seconds
+    #before it should, and then sleeps off and cannot wake up in time.
+    #We lose the  message this way.
+
     now = datetime.datetime.now()
     schedule = kwargs['schedule']
     cron = croniter.croniter(schedule, now)
@@ -54,7 +62,7 @@ def start_audit(**kwargs):
         now = datetime.datetime.now()
         logging.warning(str(now) + str(next_iteration))
         if now > next_iteration:
-            do_something()
+            do_something(**kwargs['mq_args'])
             next_iteration = cron.get_next(datetime.datetime)
         else:
             sleep_time = (next_iteration - now).total_seconds()
@@ -73,16 +81,22 @@ def register_audit(args):
     # Now validate cfg
     conf_file = os.path.join(SCRIPT_REPO, args.conf)
     validate_cfg(conf_file)
+
     # Now pick out relevant info
-    kwargs = {}
+    # TODO(praneshp) eventually this must become a function call
     with open(conf_file, 'r') as json_data:
         data = json.load(json_data)
-        kwargs['username'] = data['username']
-        # TODO(praneshp) eventually this must become a function call
-        # somewhere else
-        kwargs['sshkey'] = utils.get_key_path()
-        kwargs['name'] = data['name']
-        kwargs['schedule'] = data['cron-freq']
+        # stuff for the message queue
+        mq_args = {'mq_host': data['mq_host'],
+                   'mq_port': data['mq_port'],
+                   'mq_user': data['mq_user'],
+                   'mq_password': data['mq_password']}
+
+        # general stuff for the audit module
+        kwargs = {'sshkey': utils.get_key_path(),
+                  'name': data['name'],
+                  'schedule': data['cron-freq'],
+                  'mq_args': mq_args}
 
     #Start a thread to run a cron job for this audit script
     t = threading.Thread(name=kwargs['name'], target=start_audit,
@@ -99,6 +113,7 @@ def register_repair(args):
 
 def init():
     logging.warning('Initializing')
+    #TODO(praneshp): come up with  to start all registered reaction scripts
 
 
 def parse():
@@ -124,6 +139,8 @@ def parse():
 
 
 if __name__ == '__main__':
+    #TODO(praneshp): AMQP, json->yaml, reaction scripts(after amqp)
     logging.basicConfig(filename=os.path.join(
                         LOG_REPO, 'entropy-' + str(time.time()) + '.log'))
+    init()
     parse()

entropy/queues.py

@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright (C) 2013 Yahoo! Inc. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from kombu import Exchange
+from kombu import Queue
+
+PASS_KEY = 'pass'
+FAIL_KEY = 'fail'
+
+entropy_exchange = Exchange('entropy_exchage', type='fanout')
+pass_events = Queue('pass', entropy_exchange, routing_key=PASS_KEY)
+fail_events = Queue('fail', entropy_exchange, routing_key=FAIL_KEY)

entropy/react.json

@@ -0,0 +1,10 @@
+{
+    "name" : "react",
+    "hostname" : "localhost",
+    "username" : "praneshp",
+    "ssh-key" : "id_rsa",
+    "mq_host": "localhost",
+    "mq_port": "5672",
+    "mq_user": "guest",
+    "mq_password": "guest"
+}

entropy/react.py

@@ -0,0 +1,66 @@
+# Copyright (C) 2013 Yahoo! Inc. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+import json
+import logging
+import os
+
+from kombu import BrokerConnection
+from kombu.mixins import ConsumerMixin
+
+from queues import pass_events
+
+
+SCRIPT_REPO = os.path.dirname(__file__)
+conf_file = os.path.join(SCRIPT_REPO, 'react.json')
+
+
+class SomeConsumer(ConsumerMixin):
+    def __init__(self, connection):
+        self.connection = connection
+        return
+
+    def get_consumers(self, Consumer, channel):
+        return [Consumer(pass_events, callbacks=[self.on_message])]
+
+    def on_message(self, body, message):
+        logging.warning("Received message: %r" % body)
+        message.ack()
+        return
+
+
+def recv_message(**kwargs):
+    connection = BrokerConnection('amqp://%(mq_user)s:%(mq_password)s@'
+                                  '%(mq_host)s:%(mq_port)s//' % kwargs)
+    with connection as conn:
+        try:
+            SomeConsumer(conn).run()
+        except KeyboardInterrupt:
+            logging.warning('Quitting %s' % __name__)
+
+
+def parse_conf():
+    with open(conf_file, 'r') as json_data:
+        data = json.load(json_data)
+        # stuff for the message queue
+        mq_args = {'mq_host': data['mq_host'],
+                   'mq_port': data['mq_port'],
+                   'mq_user': data['mq_user'],
+                   'mq_password': data['mq_password']}
+        return mq_args
+
+
+if __name__ == '__main__':
+    logging.warning('starting react script %s' % __file__)
+    mq_args = parse_conf()
+    recv_message(**mq_args)

entropy/runthis.json

@@ -1,7 +0,0 @@
-{
-    "name" : "runthis",
-    "hostname" : "localhost",
-    "cron-freq" :"*/5 * * * *",
-    "username" : "praneshp",
-    "ssh-key" : "id_rsa"
-}

requirements.txt

@@ -2,4 +2,4 @@
 Pbr>=0.5.21,<1.0
 sphinx>=1.1.2,<1.2
 croniter>=0.3.3
-
+kombu==3.0.7

tox.ini

@@ -22,6 +22,6 @@ commands =
 commands = {posargs}
 
 [flake8]
-ignore = H233
+ignore = H233,H302,H304
 builtins = _
 exclude = .idea,.tox,docs,.git