class MessageBusClient:
def __init__(self, host=None, port=None, route=None, ssl=None):
config_overrides = dict(host=host, port=port, route=route, ssl=ssl)
self.config = load_message_bus_config(**config_overrides)
self.emitter = ExecutorEventEmitter()
self.client = self.create_client()
self.retry = 5
self.connected_event = Event()
self.started_running = False
@staticmethod
def build_url(host, port, route, ssl):
return '{scheme}://{host}:{port}{route}'.format(
scheme='wss' if ssl else 'ws',
host=host,
port=str(port),
route=route)
def create_client(self):
url = MessageBusClient.build_url(ssl=self.config.ssl,
host=self.config.host,
port=self.config.port,
route=self.config.route)
return WebSocketApp(url,
on_open=self.on_open,
on_close=self.on_close,
on_error=self.on_error,
on_message=self.on_message)
def on_open(self):
LOG.info("Connected")
self.connected_event.set()
self.emitter.emit("open")
# Restore reconnect timer to 5 seconds on sucessful connect
self.retry = 5
def on_close(self):
self.emitter.emit("close")
def on_error(self, error):
""" On error start trying to reconnect to the websocket. """
if isinstance(error, WebSocketConnectionClosedException):
LOG.warning('Could not send message because connection has closed')
else:
LOG.exception('=== ' + repr(error) + ' ===')
try:
self.emitter.emit('error', error)
if self.client.keep_running:
self.client.close()
except Exception as e:
LOG.error('Exception closing websocket: ' + repr(e))
LOG.warning("Message Bus Client will reconnect in %d seconds." %
self.retry)
time.sleep(self.retry)
self.retry = min(self.retry * 2, 60)
try:
self.emitter.emit('reconnecting')
self.client = self.create_client()
self.run_forever()
except WebSocketException:
pass
def on_message(self, message):
parsed_message = Message.deserialize(message)
self.emitter.emit('message', message)
self.emitter.emit(parsed_message.msg_type, parsed_message)
def emit(self, message):
if not self.connected_event.wait(10):
if not self.started_running:
raise ValueError('You must execute run_forever() '
'before emitting messages')
self.connected_event.wait()
try:
if hasattr(message, 'serialize'):
self.client.send(message.serialize())
else:
self.client.send(json.dumps(message.__dict__))
except WebSocketConnectionClosedException:
LOG.warning('Could not send {} message because connection '
'has been closed'.format(message.msg_type))
def wait_for_message(self, message_type, timeout=3.0):
"""Wait for a message of a specific type.
Arguments:
message_type (str): the message type of the expected message
timeout: seconds to wait before timeout, defaults to 3
Returns:
The received message or None if the response timed out
"""
return MessageWaiter(self, message_type).wait(timeout)
def wait_for_response(self, message, reply_type=None, timeout=3.0):
"""Send a message and wait for a response.
Arguments:
message (Message): message to send
reply_type (str): the message type of the expected reply.
Defaults to "<message.msg_type>.response".
timeout: seconds to wait before timeout, defaults to 3
Returns:
The received message or None if the response timed out
"""
message_type = reply_type or message.msg_type + '.response'
waiter = MessageWaiter(self, message_type) # Setup response handler
# Send message and wait for it's response
self.emit(message)
return waiter.wait(timeout)
def on(self, event_name, func):
self.emitter.on(event_name, func)
def once(self, event_name, func):
self.emitter.once(event_name, func)
def remove(self, event_name, func):
try:
if event_name in self.emitter._events:
LOG.debug("Removing found '" + str(event_name) + "'")
else:
LOG.debug("Not able to find '" + str(event_name) + "'")
self.emitter.remove_listener(event_name, func)
except ValueError:
LOG.warning('Failed to remove event {}: {}'.format(
event_name, str(func)))
for line in traceback.format_stack():
LOG.warning(line.strip())
if event_name in self.emitter._events:
LOG.debug("Removing found '" + str(event_name) + "'")
else:
LOG.debug("Not able to find '" + str(event_name) + "'")
LOG.warning("Existing events: " + str(self.emitter._events))
for evt in self.emitter._events:
LOG.warning(" " + str(evt))
LOG.warning(" " + str(self.emitter._events[evt]))
if event_name in self.emitter._events:
LOG.debug("Removing found '" + str(event_name) + "'")
else:
LOG.debug("Not able to find '" + str(event_name) + "'")
LOG.warning('----- End dump -----')
def remove_all_listeners(self, event_name):
'''
Remove all listeners connected to event_name.
Args:
event_name: event from which to remove listeners
'''
if event_name is None:
raise ValueError
self.emitter.remove_all_listeners(event_name)
def run_forever(self):
self.started_running = True
self.client.run_forever()
def close(self):
self.client.close()
self.connected_event.clear()
class MessageBusClient:
def __init__(self, host='0.0.0.0', port=8181, route='/core', ssl=False):
self.config = MessageBusClientConf(host, port, route, ssl)
self.emitter = ExecutorEventEmitter()
self.client = self.create_client()
self.retry = 5
self.connected_event = Event()
self.started_running = False
@staticmethod
def build_url(host, port, route, ssl):
return '{scheme}://{host}:{port}{route}'.format(
scheme='wss' if ssl else 'ws',
host=host,
port=str(port),
route=route)
def create_client(self):
url = MessageBusClient.build_url(ssl=self.config.ssl,
host=self.config.host,
port=self.config.port,
route=self.config.route)
return WebSocketApp(url, on_open=self.on_open, on_close=self.on_close,
on_error=self.on_error, on_message=self.on_message)
def on_open(self):
LOG.info("Connected")
self.connected_event.set()
self.emitter.emit("open")
# Restore reconnect timer to 5 seconds on sucessful connect
self.retry = 5
def on_close(self):
self.emitter.emit("close")
def on_error(self, error):
""" On error start trying to reconnect to the websocket. """
if isinstance(error, WebSocketConnectionClosedException):
LOG.warning('Could not send message because connection has closed')
else:
LOG.exception('=== ' + repr(error) + ' ===')
try:
self.emitter.emit('error', error)
if self.client.keep_running:
self.client.close()
except Exception as e:
LOG.error('Exception closing websocket: ' + repr(e))
LOG.warning(
"Message Bus Client will reconnect in %d seconds." % self.retry
)
time.sleep(self.retry)
self.retry = min(self.retry * 2, 60)
try:
self.emitter.emit('reconnecting')
self.client = self.create_client()
self.run_forever()
except WebSocketException:
pass
def on_message(self, message):
parsed_message = Message.deserialize(message)
self.emitter.emit('message', message)
self.emitter.emit(parsed_message.msg_type, parsed_message)
def emit(self, message):
if not self.connected_event.wait(10):
if not self.started_running:
raise ValueError('You must execute run_forever() '
'before emitting messages')
self.connected_event.wait()
try:
if hasattr(message, 'serialize'):
self.client.send(message.serialize())
else:
self.client.send(json.dumps(message.__dict__))
except WebSocketConnectionClosedException:
LOG.warning('Could not send {} message because connection '
'has been closed'.format(message.msg_type))
def wait_for_response(self, message, reply_type=None, timeout=None):
"""Send a message and wait for a response.
Args:
message (Message): message to send
reply_type (str): the message type of the expected reply.
Defaults to "<message.msg_type>.response".
timeout: seconds to wait before timeout, defaults to 3
Returns:
The received message or None if the response timed out
"""
response = []
def handler(message):
"""Receive response data."""
response.append(message)
# Setup response handler
self.once(reply_type or message.msg_type + '.response', handler)
# Send request
self.emit(message)
# Wait for response
start_time = time.monotonic()
while len(response) == 0:
time.sleep(0.2)
if time.monotonic() - start_time > (timeout or 3.0):
try:
self.remove(reply_type, handler)
except (ValueError, KeyError):
# ValueError occurs on pyee 1.0.1 removing handlers
# registered with once.
# KeyError may theoretically occur if the event occurs as
# the handler is removed
pass
return None
return response[0]
def on(self, event_name, func):
self.emitter.on(event_name, func)
def once(self, event_name, func):
self.emitter.once(event_name, func)
def remove(self, event_name, func):
try:
if not event_name in self.emitter._events:
LOG.debug("Not able to find '"+str(event_name)+"'")
self.emitter.remove_listener(event_name, func)
except ValueError:
LOG.warning('Failed to remove event {}: {}'.format(event_name,
str(func)))
for line in traceback.format_stack():
LOG.warning(line.strip())
if not event_name in self.emitter._events:
LOG.debug("Not able to find '"+str(event_name)+"'")
LOG.warning("Existing events: " + str(self.emitter._events))
for evt in self.emitter._events:
LOG.warning(" "+str(evt))
LOG.warning(" "+str(self.emitter._events[evt]))
if event_name in self.emitter._events:
LOG.debug("Removing found '"+str(event_name)+"'")
else:
LOG.debug("Not able to find '"+str(event_name)+"'")
LOG.warning('----- End dump -----')
def remove_all_listeners(self, event_name):
"""Remove all listeners connected to event_name.
Arguments:
event_name: event from which to remove listeners
"""
if event_name is None:
raise ValueError
self.emitter.remove_all_listeners(event_name)
def run_forever(self):
self.started_running = True
self.client.run_forever()
def close(self):
self.client.close()
self.connected_event.clear()
def run_in_thread(self):
"""Launches the run_forever in a separate daemon thread."""
t = Thread(target=self.run_forever)
t.daemon = True
t.start()
return t