def purge_queue() -> None:
"""
Deletes all MessageLog objects with status `IN_PROGRESS` or `PUBLISHED` add iterate through and purge all RabbitMQ
queues
"""
queued_messages = MessageLog.objects.filter(
status__in=['IN_PROGRESS', 'PUBLISHED'])
queued_messages.delete()
try:
carrot_settings = settings.CARROT
except AttributeError:
carrot_settings = {
'default_broker': DEFAULT_BROKER,
}
queues = carrot_settings.get('queues', [{
'name': 'default',
'host': DEFAULT_BROKER
}])
for queue in queues:
if type(queue['host']) is str:
filters = {'url': queue['host']}
else:
filters = queue['host']
host = VirtualHost(**filters)
channel = host.blocking_connection.channel()
channel.queue_purge(queue=queue['name'])
def get_host_from_name(name: str) -> VirtualHost:
"""
Gets a host object from a given queue name based on the Django configuration
If no queue name is provided (as may be the case from some callers), this function returns a VirtualHost based on
the CARROT.default_broker value.
May raise an exception if the given queue name is not registered in the settings.
"""
try:
carrot_settings = settings.CARROT
except AttributeError:
carrot_settings = {
'default_broker': DEFAULT_BROKER,
'queues': [{
'name': 'default',
'host': DEFAULT_BROKER
}]
}
try:
if not name:
try:
conf = carrot_settings.get('default_broker', {})
except AttributeError:
conf = {}
if not conf:
conf = {'url': DEFAULT_BROKER}
elif isinstance(conf, str):
conf = {'url': conf}
return VirtualHost(**conf)
queues = carrot_settings.get('queues', [])
queue_host = list(filter(lambda queue: queue['name'] == name,
queues))[0]['host']
try:
vhost = VirtualHost(**queue_host)
except TypeError:
vhost = VirtualHost(url=queue_host)
return vhost
except IndexError:
raise CarrotConfigException(
'Cannot find queue called %s in settings.CARROT queue list' % name)
def runner(options):
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
sys.path.append(BASE_DIR)
vhost = {
'host': options.host,
'port': options.port,
'name': options.name,
'username': options.username,
'password': options.password,
'secure': options.secure,
}
_vhost = VirtualHost(**vhost)
settings.configure(
DEBUG=True,
DATABASES={
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': 'local',
}
},
ROOT_URLCONF='carrot.urls',
INSTALLED_APPS=(
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.admin',
'django.contrib.staticfiles',
'carrot',
),
CARROT={
'default_broker': str(_vhost),
},
TEMPLATES=[
{
'BACKEND': 'django.template.backends.django.DjangoTemplates',
'DIRS': [os.path.join(BASE_DIR, 'templates')],
'APP_DIRS': True,
'OPTIONS': {
'context_processors': [
'django.template.context_processors.debug',
'django.template.context_processors.request',
'django.contrib.auth.context_processors.auth',
'django.contrib.messages.context_processors.messages',
],
},
},
],
STATIC_URL='/static/',
)
django.setup()
from django.test.runner import DiscoverRunner
test_runner = DiscoverRunner(verbosity=0, )
failures = test_runner.run_tests(['carrot'])
if failures:
sys.exit(failures)
def test_consumer_set(self, *args):
alt_settings = {
'queues': [{
'name': 'test',
'durable': True,
'queue_arguments': {'blah': True},
'exchange_arguments': {'blah': True},
}]
}
with override_settings(CARROT=alt_settings):
cs = ConsumerSet(VirtualHost('amqp://*****:*****@localhost:5672/test'), 'test', logger)
cs.start_consuming()
cs.stop_consuming()
def handle(self, **options):
"""
The actual handler process. Performs the following actions:
- Initiates and starts a new :class:`carrot.objects.ScheduledTaskManager`, which schedules all *active*
:class:`carrot.objects.ScheduledTask` instances to run at the given intervals. This only happens if the
**--no-scheduler** argument has not been provided - otherwise, the service only creates consumer objects
- Loops through the queues registered in your Django project's settings module, and starts a
new :class:`carrot.objects.ConsumerSet` for them. Each ConsumerSet will contain **n**
:class:`carrot.objects.Consumer` objects, where **n** is the concurrency setting for the given queue (as
defined in the Django settings)
- Enters into an infinite loop which monitors your database for changes to your database - if any changes
to the :class:`carrot.objects.ScheduledTask` queryset are detected, carrot updates the scheduler
accordingly
On receiving a **KeyboardInterrupt**, **SystemExit** or SIGTERM, the service first turns off each of the
schedulers in turn (so no new tasks can be published to RabbitMQ), before turning off the Consumers in turn.
The more Consumers/ScheduledTask objects you have, the longer this will take.
:param options: provided by **argparse** (see above for the full list of available options)
"""
signal.signal(signal.SIGTERM, self.terminate)
# check if carrot service is already running, and warn the user if so
running_pids = []
for q in psutil.process_iter():
if 'python' in q.name():
if len(q.cmdline()) > 1 and 'manage.py' in q.cmdline(
)[1] and 'carrot' in q.cmdline()[2]:
if not q._pid == os.getpgid(0):
running_pids.append(q._pid)
if running_pids:
self.stdout.write(
self.style.WARNING(
'WARNING: Carrot service is already running with the following PID. Running more '
'than one instance of carrot may lead to a memory leak:\n%s'
% '\n'.join([str(pid) for pid in running_pids])))
run_scheduler = options['run_scheduler']
try:
queues = [
q for q in settings.CARROT['queues']
if q.get('consumable', True)
]
except (AttributeError, KeyError):
queues = [{'name': 'default', 'host': DEFAULT_BROKER}]
if run_scheduler:
self.scheduler = ScheduledTaskManager()
try:
# scheduler
if self.scheduler:
self.scheduler.start()
self.stdout.write(
self.style.SUCCESS('Successfully started scheduler'))
# logger
loglevel = getattr(logging, options.get('loglevel', 'DEBUG'))
logger = logging.getLogger('carrot')
logger.setLevel(loglevel)
file_handler = logging.FileHandler(options['logfile'])
file_handler.setLevel(loglevel)
stream_handler = logging.StreamHandler()
stream_handler.setLevel(loglevel)
formatter = logging.Formatter(LOGGING_FORMAT)
file_handler.setFormatter(formatter)
stream_handler.setFormatter(formatter)
logger.addHandler(file_handler)
logger.addHandler(stream_handler)
# consumers
for queue in queues:
kwargs = {
'queue': queue['name'],
'logger': logger,
'concurrency': queue.get('concurrency', 1),
}
if queue.get('consumer_class', None):
kwargs['consumer_class'] = queue.get('consumer_class')
try:
vhost = VirtualHost(**queue['host'])
except TypeError:
vhost = VirtualHost(url=queue['host'])
c = ConsumerSet(host=vhost, **kwargs)
c.start_consuming()
self.active_consumer_sets.append(c)
self.stdout.write(
self.style.SUCCESS(
'Successfully started %i consumers for queue %s' %
(c.concurrency, queue['name'])))
self.stdout.write(
self.style.SUCCESS(
'All queues consumer sets started successfully. Full logs are at %s.'
% options['logfile']))
qs = ScheduledTask.objects.filter(active=True)
self.pks = [t.pk for t in qs]
while True:
time.sleep(1)
if not self.run:
self.terminate()
if self.scheduler or options['testmode']:
new_qs = ScheduledTask.objects.filter(active=True)
if new_qs.count() > len(self.pks):
print(
'New active scheduled tasks have been added to the queryset'
)
new_tasks = new_qs.exclude(
pk__in=self.pks) or [ScheduledTask()]
for new_task in new_tasks:
print('adding new task %s' % new_task)
self.scheduler.add_task(new_task)
self.pks = [t.pk for t in new_qs]
elif new_qs.count() < len(self.pks):
self.pks = [t.pk for t in new_qs]
if options['testmode']:
print('TESTMODE:', options['testmode'])
raise SystemExit()
except Exception as err:
self.stderr.write(self.style.ERROR(err))
except (KeyboardInterrupt, SystemExit):
# self.terminate()
pass
def test_consumer(self, *args):
consumer = Consumer(VirtualHost('amqp://*****:*****@localhost:5672/test'), 'test', logger, 'test')
consumer.task_log = ['blah']
log = MessageLog.objects.create(task='carrot.tests.test_task', uuid=1234, status='PUBLISHED', task_args='()')
consumer.get_task_type({'type': 'carrot.tests.test_task'}, None)
p = Properties()
self.assertEqual(consumer.get_message_log(p, None), log)
p.message_id = 4321
consumer.get_message_log(p, None)
consumer.fail(log, 'test error')
consumer.connection = consumer.connect()
consumer.run()
consumer.reconnect()
consumer.on_connection_open(consumer.connection)
consumer.channel = consumer.connection.channel
consumer.on_channel_open(consumer.channel)
consumer.on_exchange_declare()
consumer.on_queue_declare()
consumer.on_bind()
p.message_id = 1234
consumer.on_message(consumer.channel, p, p, b'{}')
log.status = 'PUBLISHED'
log.save()
consumer.on_message(consumer.channel, p, p, b'{}')
consumer.on_channel_closed(consumer.channel, 1, 'blah')
p.headers = {'type':'carrot.tests.test_task'}
log.delete()
log = MessageLog.objects.create(task='carrot.tests.test_task', uuid=1234, status='PUBLISHED', task_args='()')
self.assertEqual(str(log), 'carrot.tests.test_task')
consumer.on_message(consumer.channel, p, p, b'{}')
log.delete()
p.headers = {'type': 'carrot.tests.dict_task'}
log = MessageLog.objects.create(task='carrot.tests.dict_task', uuid=1234, status='PUBLISHED', task_args='()')
consumer.on_message(consumer.channel, p, p, b'{}')
log.delete()
p.headers = {'type':'carrot.tests.failing_task'}
log = MessageLog.objects.create(task='carrot.tests.failing_task', uuid=1234, status='PUBLISHED', task_args='()')
consumer.on_message(consumer.channel, p, p, b'{}')
log.delete()
log = MessageLog.objects.create(task='carrot.tests.test_task', uuid=1234, status='PUBLISHED', task_args='()')
consumer.serializer = MessageSerializer()
consumer.on_message(consumer.channel, p, p, b'{}')
log.delete()
log = MessageLog.objects.create(task='carrot.tests.test_task', uuid=1234, status='PUBLISHED', task_args='()')
consumer.serializer.failing_method = 'get_task'
consumer.on_message(consumer.channel, p, p, b'{}')
consumer.active_message_log = log
consumer.on_consumer_cancelled(1)
consumer.stop()
consumer.on_cancel()
consumer.channel = None
consumer.stop()
consumer.close_connection()
consumer.on_channel_closed(consumer.channel, 1, 'blah')
consumer.on_connection_closed(consumer.connection)
consumer.shutdown_requested = True
consumer.on_channel_closed(consumer.channel, 1, 'blah')
consumer.on_connection_closed(consumer.connection)