class MQTTTransportStage(PipelineStage):
"""
PipelineStage object which is responsible for interfacing with the MQTT protocol wrapper object.
This stage handles all MQTT operations and any other operations (such as ConnectOperation) which
is not in the MQTT group of operations, but can only be run at the protocol level.
"""
@pipeline_thread.runs_on_pipeline_thread
def _cancel_active_connect_disconnect_ops(self):
"""
Cancel any running connect or disconnect op. Since our ability to "cancel" is fairly limited,
all this does (for now) is to fail the operation
"""
ops_to_cancel = []
if self._active_connect_op:
# TODO: should this actually run a cancel call on the op?
ops_to_cancel.add(self._active_connect_op)
self._active_connect_op = None
if self._active_disconnect_op:
ops_to_cancel.add(self._active_disconnect_op)
self._active_disconnect_op = None
for op in ops_to_cancel:
op.error = errors.PipelineError(
"Cancelling because new ConnectOperation, DisconnectOperation, or ReconnectOperation was issued"
)
operation_flow.complete_op(stage=self, op=op)
@pipeline_thread.runs_on_pipeline_thread
def _execute_op(self, op):
if isinstance(op, pipeline_ops_mqtt.SetMQTTConnectionArgsOperation):
# pipeline_ops_mqtt.SetMQTTConnectionArgsOperation is where we create our MQTTTransport object and set
# all of its properties.
logger.info("{}({}): got connection args".format(
self.name, op.name))
self.hostname = op.hostname
self.username = op.username
self.client_id = op.client_id
self.ca_cert = op.ca_cert
self.sas_token = op.sas_token
self.client_cert = op.client_cert
self.transport = MQTTTransport(
client_id=self.client_id,
hostname=self.hostname,
username=self.username,
ca_cert=self.ca_cert,
x509_cert=self.client_cert,
)
self.transport.on_mqtt_connected_handler = self._on_mqtt_connected
self.transport.on_mqtt_connection_failure_handler = self._on_mqtt_connection_failure
self.transport.on_mqtt_disconnected_handler = self._on_mqtt_disconnected
self.transport.on_mqtt_message_received_handler = self._on_mqtt_message_received
self._active_connect_op = None
self._active_disconnect_op = None
self.pipeline_root.transport = self.transport
operation_flow.complete_op(self, op)
elif isinstance(op, pipeline_ops_base.ConnectOperation):
logger.info("{}({}): connecting".format(self.name, op.name))
self._cancel_active_connect_disconnect_ops()
self._active_connect_op = op
try:
self.transport.connect(password=self.sas_token)
except Exception as e:
self._active_connect_op = None
raise e
elif isinstance(op, pipeline_ops_base.ReconnectOperation):
logger.info("{}({}): reconnecting".format(self.name, op.name))
# We set _active_connect_op here because a reconnect is the same as a connect for "active operation" tracking purposes.
self._cancel_active_connect_disconnect_ops()
self._active_connect_op = op
try:
self.transport.reconnect(password=self.sas_token)
except Exception as e:
self._active_connect_op = None
raise e
elif isinstance(op, pipeline_ops_base.DisconnectOperation):
logger.info("{}({}): disconnecting".format(self.name, op.name))
self._cancel_active_connect_disconnect_ops()
self._active_disconnect_op = op
try:
self.transport.disconnect()
except Exception as e:
self._active_disconnect_op = None
raise e
elif isinstance(op, pipeline_ops_mqtt.MQTTPublishOperation):
logger.info("{}({}): publishing on {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_published():
logger.info("{}({}): PUBACK received. completing op.".format(
self.name, op.name))
operation_flow.complete_op(self, op)
self.transport.publish(topic=op.topic,
payload=op.payload,
callback=on_published)
elif isinstance(op, pipeline_ops_mqtt.MQTTSubscribeOperation):
logger.info("{}({}): subscribing to {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_subscribed():
logger.info("{}({}): SUBACK received. completing op.".format(
self.name, op.name))
operation_flow.complete_op(self, op)
self.transport.subscribe(topic=op.topic, callback=on_subscribed)
elif isinstance(op, pipeline_ops_mqtt.MQTTUnsubscribeOperation):
logger.info("{}({}): unsubscribing from {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_unsubscribed():
logger.info(
"{}({}): UNSUBACK received. completing op.".format(
self.name, op.name))
operation_flow.complete_op(self, op)
self.transport.unsubscribe(topic=op.topic,
callback=on_unsubscribed)
else:
operation_flow.pass_op_to_next_stage(self, op)
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_message_received(self, topic, payload):
"""
Handler that gets called by the protocol library when an incoming message arrives.
Convert that message into a pipeline event and pass it up for someone to handle.
"""
operation_flow.pass_event_to_previous_stage(
stage=self,
event=pipeline_events_mqtt.IncomingMQTTMessageEvent(
topic=topic, payload=payload),
)
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_connected(self):
"""
Handler that gets called by the transport when it connects.
"""
logger.info("_on_mqtt_connected called")
# self.on_connected() tells other pipeilne stages that we're connected. Do this before
# we do anything else (in case upper stages have any "are we connected" logic.
self.on_connected()
if self._active_connect_op:
logger.info("completing connect op")
op = self._active_connect_op
self._active_connect_op = None
operation_flow.complete_op(stage=self, op=op)
else:
logger.warning("Connection was unexpected")
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_connection_failure(self, cause):
"""
Handler that gets called by the transport when a connection fails.
"""
logger.error("{}: _on_mqtt_connection_failure called: {}".format(
self.name, cause))
if self._active_connect_op:
logger.info("{}: failing connect op".format(self.name))
op = self._active_connect_op
self._active_connect_op = None
op.error = cause
operation_flow.complete_op(stage=self, op=op)
else:
logger.warning("{}: Connection failure was unexpected".format(
self.name))
unhandled_exceptions.exception_caught_in_background_thread(cause)
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_disconnected(self, cause):
"""
Handler that gets called by the transport when the transport disconnects.
"""
logger.error("{}: _on_mqtt_disconnect called: {}".format(
self.name, cause))
# self.on_disconnected() tells other pipeilne stages that we're disconnected. Do this before
# we do anything else (in case upper stages have any "are we connected" logic.
self.on_disconnected()
# regardless of the cause, we wrap it in a ConnectionDroppedError object because that's
# the real problem at this point.
if cause:
try:
six.raise_from(errors.ConnectionDroppedError, cause)
except errors.ConnectionDroppedError as e:
cause = e
if self._active_disconnect_op:
logger.info("{}: completing disconnect op".format(self.name))
op = self._active_disconnect_op
self._active_disconnect_op = None
op.error = cause
operation_flow.complete_op(stage=self, op=op)
else:
logger.warning("{}: disconnection was unexpected".format(
self.name))
unhandled_exceptions.exception_caught_in_background_thread(cause)
class MQTTClientStage(PipelineStage):
"""
PipelineStage object which is responsible for interfacing with the MQTT protocol wrapper object.
This stage handles all MQTT operations and any other operations (such as ConnectOperation) which
is not in the MQTT group of operations, but can only be run at the protocol level.
"""
@pipeline_thread.runs_on_pipeline_thread
def _run_op(self, op):
if isinstance(op, pipeline_ops_mqtt.SetMQTTConnectionArgsOperation):
# pipeline_ops_mqtt.SetMQTTConnectionArgsOperation is where we create our MQTTTransport object and set
# all of its properties.
logger.info("{}({}): got connection args".format(
self.name, op.name))
self.hostname = op.hostname
self.username = op.username
self.client_id = op.client_id
self.ca_cert = op.ca_cert
self.sas_token = None
self.trusted_certificate_chain = None
self.transport = MQTTTransport(
client_id=self.client_id,
hostname=self.hostname,
username=self.username,
ca_cert=self.ca_cert,
)
self.transport.on_mqtt_connected = self.on_connected
self.transport.on_mqtt_disconnected = self.on_disconnected
self.transport.on_mqtt_message_received = self._on_message_received
self.pipeline_root.transport = self.transport
operation_flow.complete_op(self, op)
elif isinstance(op, pipeline_ops_base.SetSasTokenOperation):
# When we get a sas token from above, we just save it for later
logger.info("{}({}): got password".format(self.name, op.name))
self.sas_token = op.sas_token
operation_flow.complete_op(self, op)
elif isinstance(
op,
pipeline_ops_base.SetClientAuthenticationCertificateOperation):
# When we get a certificate from above, we just save it for later
logger.info("{}({}): got certificate".format(self.name, op.name))
self.trusted_certificate_chain = op.certificate
operation_flow.complete_op(self, op)
elif isinstance(op, pipeline_ops_base.ConnectOperation):
logger.info("{}({}): conneting".format(self.name, op.name))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_connected():
logger.info("{}({}): on_connected. completing op.".format(
self.name, op.name))
self.transport.on_mqtt_connected = self.on_connected
self.on_connected()
operation_flow.complete_op(self, op)
# A note on exceptions handling in Connect, Disconnct, and Reconnet:
#
# All calls into self.transport can raise an exception, and this is OK.
# The exception handler in PipelineStage.run_op() will catch these errors
# and propagate them to the caller. This is an intentional design of the
# pipeline, that stages, etc, don't need to worry about catching exceptions
# except for special cases.
#
# The code right below this comment is This is a special case. In addition
# to this "normal" exception handling, we add another exception handler
# into this class' Connect, Reconnect, and Disconnect code. We need to
# do this because transport.on_mqtt_connected and transport.on_mqtt_disconnected
# are both _handler_ functions instead of _callbacks_.
#
# Because they're handlers instead of callbacks, we need to change the
# handlers while the connection is established. We do this so we can
# know when the protocol is connected so we can move on to the next step.
# Once the connection is established, we change the handler back to its
# old value before finishing.
#
# The exception handling below is to reset the handler back to its original
# value in the case where transport.connect raises an exception. Again,
# this extra exception handling is only necessary in the Connect, Disconnect,
# and Reconnect case because they're the only cases that use handlers instead
# of callbacks.
#
self.transport.on_mqtt_connected = on_connected
try:
self.transport.connect(
password=self.sas_token,
client_certificate=self.trusted_certificate_chain)
except Exception as e:
self.transport.on_mqtt_connected = self.on_connected
raise e
elif isinstance(op, pipeline_ops_base.ReconnectOperation):
logger.info("{}({}): reconnecting".format(self.name, op.name))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_connected():
logger.info("{}({}): on_connected. completing op.".format(
self.name, op.name))
self.transport.on_mqtt_connected = self.on_connected
self.on_connected()
operation_flow.complete_op(self, op)
# See "A note on exception handling" above
self.transport.on_mqtt_connected = on_connected
try:
self.transport.reconnect(self.sas_token)
except Exception as e:
self.transport.on_mqtt_connected = self.on_connected
raise e
elif isinstance(op, pipeline_ops_base.DisconnectOperation):
logger.info("{}({}): disconnecting".format(self.name, op.name))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_disconnected():
logger.info("{}({}): on_disconnected. completing op.".format(
self.name, op.name))
self.transport.on_mqtt_disconnected = self.on_disconnected
self.on_disconnected()
operation_flow.complete_op(self, op)
# See "A note on exception handling" above
self.transport.on_mqtt_disconnected = on_disconnected
try:
self.transport.disconnect()
except Exception as e:
self.transport.on_mqtt_disconnected = self.on_disconnected
raise e
elif isinstance(op, pipeline_ops_mqtt.MQTTPublishOperation):
logger.info("{}({}): publishing on {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_published():
logger.info("{}({}): PUBACK received. completing op.".format(
self.name, op.name))
operation_flow.complete_op(self, op)
self.transport.publish(topic=op.topic,
payload=op.payload,
callback=on_published)
elif isinstance(op, pipeline_ops_mqtt.MQTTSubscribeOperation):
logger.info("{}({}): subscribing to {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_subscribed():
logger.info("{}({}): SUBACK received. completing op.".format(
self.name, op.name))
operation_flow.complete_op(self, op)
self.transport.subscribe(topic=op.topic, callback=on_subscribed)
elif isinstance(op, pipeline_ops_mqtt.MQTTUnsubscribeOperation):
logger.info("{}({}): unsubscribing from {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_unsubscribed():
logger.info(
"{}({}): UNSUBACK received. completing op.".format(
self.name, op.name))
operation_flow.complete_op(self, op)
self.transport.unsubscribe(topic=op.topic,
callback=on_unsubscribed)
else:
operation_flow.pass_op_to_next_stage(self, op)
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_message_received(self, topic, payload):
"""
Handler that gets called by the protocol library when an incoming message arrives.
Convert that message into a pipeline event and pass it up for someone to handle.
"""
operation_flow.pass_event_to_previous_stage(
stage=self,
event=pipeline_events_mqtt.IncomingMQTTMessageEvent(
topic=topic, payload=payload),
)
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_connected(self):
super(MQTTClientStage, self).on_connected()
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_disconnected(self):
super(MQTTClientStage, self).on_disconnected()
class MQTTTransportStage(PipelineStage):
"""
PipelineStage object which is responsible for interfacing with the MQTT protocol wrapper object.
This stage handles all MQTT operations and any other operations (such as ConnectOperation) which
is not in the MQTT group of operations, but can only be run at the protocol level.
"""
@pipeline_thread.runs_on_pipeline_thread
def _cancel_pending_connection_op(self):
"""
Cancel any running connect, disconnect or reconnect op. Since our ability to "cancel" is fairly limited,
all this does (for now) is to fail the operation
"""
op = self._pending_connection_op
if op:
# TODO: should this actually run a cancel call on the op?
op.error = errors.PipelineError(
"Cancelling because new ConnectOperation, DisconnectOperation, or ReconnectOperation was issued"
)
operation_flow.complete_op(stage=self, op=op)
self._pending_connection_op = None
@pipeline_thread.runs_on_pipeline_thread
def _execute_op(self, op):
if isinstance(op, pipeline_ops_mqtt.SetMQTTConnectionArgsOperation):
# pipeline_ops_mqtt.SetMQTTConnectionArgsOperation is where we create our MQTTTransport object and set
# all of its properties.
logger.info("{}({}): got connection args".format(
self.name, op.name))
self.hostname = op.hostname
self.username = op.username
self.client_id = op.client_id
self.ca_cert = op.ca_cert
self.sas_token = op.sas_token
self.client_cert = op.client_cert
self.transport = MQTTTransport(
client_id=self.client_id,
hostname=self.hostname,
username=self.username,
ca_cert=self.ca_cert,
x509_cert=self.client_cert,
)
self.transport.on_mqtt_connected_handler = self._on_mqtt_connected
self.transport.on_mqtt_connection_failure_handler = self._on_mqtt_connection_failure
self.transport.on_mqtt_disconnected_handler = self._on_mqtt_disconnected
self.transport.on_mqtt_message_received_handler = self._on_mqtt_message_received
# There can only be one pending connection operation (Connect, Reconnect, Disconnect)
# at a time. The existing one must be completed or canceled before a new one is set.
# Currently, this means that if, say, a connect operation is the pending op and is executed
# but another connection op is begins by the time the CONACK is received, the original
# operation will be cancelled, but the CONACK for it will still be received, and complete the
# NEW operation. This is not desirable, but it is how things currently work.
# We are however, checking the type, so the CONACK from a cancelled Connect, cannot successfully
# complete a Disconnect operation.
self._pending_connection_op = None
self.pipeline_root.transport = self.transport
operation_flow.complete_op(self, op)
elif isinstance(op, pipeline_ops_base.UpdateSasTokenOperation):
logger.info("{}({}): saving sas token and completing".format(
self.name, op.name))
self.sas_token = op.sas_token
operation_flow.complete_op(self, op)
elif isinstance(op, pipeline_ops_base.ConnectOperation):
logger.info("{}({}): connecting".format(self.name, op.name))
self._cancel_pending_connection_op()
self._pending_connection_op = op
try:
self.transport.connect(password=self.sas_token)
except Exception as e:
logger.error("transport.connect raised error", exc_info=True)
self._pending_connection_op = None
op.error = e
operation_flow.complete_op(self, op)
elif isinstance(op, pipeline_ops_base.ReconnectOperation):
logger.info("{}({}): reconnecting".format(self.name, op.name))
# We set _active_connect_op here because a reconnect is the same as a connect for "active operation" tracking purposes.
self._cancel_pending_connection_op()
self._pending_connection_op = op
try:
self.transport.reconnect(password=self.sas_token)
except Exception as e:
logger.error("transport.reconnect raised error", exc_info=True)
self._pending_connection_op = None
op.error = e
operation_flow.complete_op(self, op)
elif isinstance(op, pipeline_ops_base.DisconnectOperation):
logger.info("{}({}): disconnecting".format(self.name, op.name))
self._cancel_pending_connection_op()
self._pending_connection_op = op
try:
self.transport.disconnect()
except Exception as e:
logger.error("transport.disconnect raised error",
exc_info=True)
self._pending_connection_op = None
op.error = e
operation_flow.complete_op(self, op)
elif isinstance(op, pipeline_ops_mqtt.MQTTPublishOperation):
logger.info("{}({}): publishing on {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_published():
logger.info("{}({}): PUBACK received. completing op.".format(
self.name, op.name))
operation_flow.complete_op(self, op)
self.transport.publish(topic=op.topic,
payload=op.payload,
callback=on_published)
elif isinstance(op, pipeline_ops_mqtt.MQTTSubscribeOperation):
logger.info("{}({}): subscribing to {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_subscribed():
logger.info("{}({}): SUBACK received. completing op.".format(
self.name, op.name))
operation_flow.complete_op(self, op)
self.transport.subscribe(topic=op.topic, callback=on_subscribed)
elif isinstance(op, pipeline_ops_mqtt.MQTTUnsubscribeOperation):
logger.info("{}({}): unsubscribing from {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_unsubscribed():
logger.info(
"{}({}): UNSUBACK received. completing op.".format(
self.name, op.name))
operation_flow.complete_op(self, op)
self.transport.unsubscribe(topic=op.topic,
callback=on_unsubscribed)
else:
operation_flow.pass_op_to_next_stage(self, op)
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_message_received(self, topic, payload):
"""
Handler that gets called by the protocol library when an incoming message arrives.
Convert that message into a pipeline event and pass it up for someone to handle.
"""
operation_flow.pass_event_to_previous_stage(
stage=self,
event=pipeline_events_mqtt.IncomingMQTTMessageEvent(
topic=topic, payload=payload),
)
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_connected(self):
"""
Handler that gets called by the transport when it connects.
"""
logger.info("_on_mqtt_connected called")
# self.on_connected() tells other pipeline stages that we're connected. Do this before
# we do anything else (in case upper stages have any "are we connected" logic.
self.on_connected()
if isinstance(self._pending_connection_op,
pipeline_ops_base.ConnectOperation) or isinstance(
self._pending_connection_op,
pipeline_ops_base.ReconnectOperation):
logger.info("completing connect op")
op = self._pending_connection_op
self._pending_connection_op = None
operation_flow.complete_op(stage=self, op=op)
else:
# This should indicate something odd is going on.
# If this occurs, either a connect was completed while there was no pending op,
# OR that a connect was completed while a disconnect op was pending
logger.warning("Connection was unexpected")
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_connection_failure(self, cause):
"""
Handler that gets called by the transport when a connection fails.
:param Exception cause: The Exception that caused the connection failure.
"""
logger.error("{}: _on_mqtt_connection_failure called: {}".format(
self.name, cause))
if isinstance(self._pending_connection_op,
pipeline_ops_base.ConnectOperation) or isinstance(
self._pending_connection_op,
pipeline_ops_base.ReconnectOperation):
logger.info("{}: failing connect op".format(self.name))
op = self._pending_connection_op
self._pending_connection_op = None
op.error = cause
operation_flow.complete_op(stage=self, op=op)
else:
logger.warning("{}: Connection failure was unexpected".format(
self.name))
unhandled_exceptions.exception_caught_in_background_thread(cause)
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_disconnected(self, cause=None):
"""
Handler that gets called by the transport when the transport disconnects.
:param Exception cause: The Exception that caused the disconnection, if any (optional)
"""
logger.error("{}: _on_mqtt_disconnect called: {}".format(
self.name, cause))
# self.on_disconnected() tells other pipeilne stages that we're disconnected. Do this before
# we do anything else (in case upper stages have any "are we connected" logic.
self.on_disconnected()
if isinstance(self._pending_connection_op,
pipeline_ops_base.DisconnectOperation):
logger.info("{}: completing disconnect op".format(self.name))
op = self._pending_connection_op
self._pending_connection_op = None
if cause:
# Only create a ConnnectionDroppedError if there is a cause,
# i.e. unexpected disconnect.
try:
six.raise_from(errors.ConnectionDroppedError, cause)
except errors.ConnectionDroppedError as e:
op.error = e
operation_flow.complete_op(stage=self, op=op)
else:
logger.warning("{}: disconnection was unexpected".format(
self.name))
# Regardless of cause, it is now a ConnectionDroppedError
try:
six.raise_from(errors.ConnectionDroppedError, cause)
except errors.ConnectionDroppedError as e:
unhandled_exceptions.exception_caught_in_background_thread(e)
class MQTTTransportStage(PipelineStage):
"""
PipelineStage object which is responsible for interfacing with the MQTT protocol wrapper object.
This stage handles all MQTT operations and any other operations (such as ConnectOperation) which
is not in the MQTT group of operations, but can only be run at the protocol level.
"""
@pipeline_thread.runs_on_pipeline_thread
def _cancel_pending_connection_op(self):
"""
Cancel any running connect, disconnect or reconnect op. Since our ability to "cancel" is fairly limited,
all this does (for now) is to fail the operation
"""
op = self._pending_connection_op
if op:
# NOTE: This code path should NOT execute in normal flow. There should never already be a pending
# connection op when another is added, due to the SerializeConnectOps stage.
# If this block does execute, there is a bug in the codebase.
error = pipeline_exceptions.OperationCancelled(
"Cancelling because new ConnectOperation, DisconnectOperation, or ReconnectOperation was issued"
) # TODO: should this actually somehow cancel the operation?
op.complete(error=error)
self._pending_connection_op = None
@pipeline_thread.runs_on_pipeline_thread
def _execute_op(self, op):
if isinstance(op, pipeline_ops_mqtt.SetMQTTConnectionArgsOperation):
# pipeline_ops_mqtt.SetMQTTConnectionArgsOperation is where we create our MQTTTransport object and set
# all of its properties.
logger.debug("{}({}): got connection args".format(
self.name, op.name))
self.hostname = op.hostname
self.username = op.username
self.client_id = op.client_id
self.ca_cert = op.ca_cert
self.sas_token = op.sas_token
self.client_cert = op.client_cert
self.transport = MQTTTransport(
client_id=self.client_id,
hostname=self.hostname,
username=self.username,
ca_cert=self.ca_cert,
x509_cert=self.client_cert,
websockets=self.pipeline_root.pipeline_configuration.
websockets,
)
self.transport.on_mqtt_connected_handler = CallableWeakMethod(
self, "_on_mqtt_connected")
self.transport.on_mqtt_connection_failure_handler = CallableWeakMethod(
self, "_on_mqtt_connection_failure")
self.transport.on_mqtt_disconnected_handler = CallableWeakMethod(
self, "_on_mqtt_disconnected")
self.transport.on_mqtt_message_received_handler = CallableWeakMethod(
self, "_on_mqtt_message_received")
# There can only be one pending connection operation (Connect, Reconnect, Disconnect)
# at a time. The existing one must be completed or canceled before a new one is set.
# Currently, this means that if, say, a connect operation is the pending op and is executed
# but another connection op is begins by the time the CONNACK is received, the original
# operation will be cancelled, but the CONNACK for it will still be received, and complete the
# NEW operation. This is not desirable, but it is how things currently work.
# We are however, checking the type, so the CONNACK from a cancelled Connect, cannot successfully
# complete a Disconnect operation.
self._pending_connection_op = None
self.pipeline_root.transport = self.transport
op.complete()
elif isinstance(op, pipeline_ops_base.UpdateSasTokenOperation):
logger.debug("{}({}): saving sas token and completing".format(
self.name, op.name))
self.sas_token = op.sas_token
op.complete()
elif isinstance(op, pipeline_ops_base.ConnectOperation):
logger.info("{}({}): connecting".format(self.name, op.name))
self._cancel_pending_connection_op()
self._pending_connection_op = op
try:
self.transport.connect(password=self.sas_token)
except Exception as e:
logger.error("transport.connect raised error")
logger.error(traceback.format_exc())
self._pending_connection_op = None
op.complete(error=e)
elif isinstance(op, pipeline_ops_base.ReconnectOperation):
logger.info("{}({}): reconnecting".format(self.name, op.name))
# We set _active_connect_op here because a reconnect is the same as a connect for "active operation" tracking purposes.
self._cancel_pending_connection_op()
self._pending_connection_op = op
try:
self.transport.reconnect(password=self.sas_token)
except Exception as e:
logger.error("transport.reconnect raised error")
logger.error(traceback.format_exc())
self._pending_connection_op = None
op.complete(error=e)
elif isinstance(op, pipeline_ops_base.DisconnectOperation):
logger.info("{}({}): disconnecting".format(self.name, op.name))
self._cancel_pending_connection_op()
self._pending_connection_op = op
try:
self.transport.disconnect()
except Exception as e:
logger.error("transport.disconnect raised error")
logger.error(traceback.format_exc())
self._pending_connection_op = None
op.complete(error=e)
elif isinstance(op, pipeline_ops_mqtt.MQTTPublishOperation):
logger.info("{}({}): publishing on {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_published():
logger.debug("{}({}): PUBACK received. completing op.".format(
self.name, op.name))
op.complete()
self.transport.publish(topic=op.topic,
payload=op.payload,
callback=on_published)
elif isinstance(op, pipeline_ops_mqtt.MQTTSubscribeOperation):
logger.info("{}({}): subscribing to {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_subscribed():
logger.debug("{}({}): SUBACK received. completing op.".format(
self.name, op.name))
op.complete()
self.transport.subscribe(topic=op.topic, callback=on_subscribed)
elif isinstance(op, pipeline_ops_mqtt.MQTTUnsubscribeOperation):
logger.info("{}({}): unsubscribing from {}".format(
self.name, op.name, op.topic))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def on_unsubscribed():
logger.debug(
"{}({}): UNSUBACK received. completing op.".format(
self.name, op.name))
op.complete()
self.transport.unsubscribe(topic=op.topic,
callback=on_unsubscribed)
else:
self.send_op_down(op)
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_message_received(self, topic, payload):
"""
Handler that gets called by the protocol library when an incoming message arrives.
Convert that message into a pipeline event and pass it up for someone to handle.
"""
self.send_event_up(
pipeline_events_mqtt.IncomingMQTTMessageEvent(topic=topic,
payload=payload))
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_connected(self):
"""
Handler that gets called by the transport when it connects.
"""
logger.info("_on_mqtt_connected called")
# self.on_connected() tells other pipeline stages that we're connected. Do this before
# we do anything else (in case upper stages have any "are we connected" logic.
self.on_connected()
if isinstance(self._pending_connection_op,
pipeline_ops_base.ConnectOperation) or isinstance(
self._pending_connection_op,
pipeline_ops_base.ReconnectOperation):
logger.debug("completing connect op")
op = self._pending_connection_op
self._pending_connection_op = None
op.complete()
else:
# This should indicate something odd is going on.
# If this occurs, either a connect was completed while there was no pending op,
# OR that a connect was completed while a disconnect op was pending
logger.warning("Connection was unexpected")
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_connection_failure(self, cause):
"""
Handler that gets called by the transport when a connection fails.
:param Exception cause: The Exception that caused the connection failure.
"""
logger.error("{}: _on_mqtt_connection_failure called: {}".format(
self.name, cause))
if isinstance(self._pending_connection_op,
pipeline_ops_base.ConnectOperation) or isinstance(
self._pending_connection_op,
pipeline_ops_base.ReconnectOperation):
logger.debug("{}: failing connect op".format(self.name))
op = self._pending_connection_op
self._pending_connection_op = None
op.complete(error=cause)
else:
logger.warning("{}: Connection failure was unexpected".format(
self.name))
handle_exceptions.handle_background_exception(cause)
@pipeline_thread.invoke_on_pipeline_thread_nowait
def _on_mqtt_disconnected(self, cause=None):
"""
Handler that gets called by the transport when the transport disconnects.
:param Exception cause: The Exception that caused the disconnection, if any (optional)
"""
if cause:
logger.error("{}: _on_mqtt_disconnect called: {}".format(
self.name, cause))
else:
logger.info("{}: _on_mqtt_disconnect called".format(self.name))
# self.on_disconnected() tells other pipeilne stages that we're disconnected. Do this before
# we do anything else (in case upper stages have any "are we connected" logic.
self.on_disconnected()
if self._pending_connection_op:
# on_mqtt_disconnected will cause any pending connect op to complete. This is how Paho
# behaves when there is a connection error, and it also makes sense that on_mqtt_disconnected
# would cause a pending connection op to fail.
logger.debug("{}: completing pending {} op".format(
self.name, self._pending_connection_op.name))
op = self._pending_connection_op
self._pending_connection_op = None
if isinstance(op, pipeline_ops_base.DisconnectOperation):
# Swallow any errors if we intended to disconnect - even if something went wrong, we
# got to the state we wanted to be in!
if cause:
handle_exceptions.swallow_unraised_exception(
cause,
log_msg=
"Unexpected disconnect with error while disconnecting - swallowing error",
)
op.complete()
else:
if cause:
op.complete(error=cause)
else:
op.complete(
error=transport_exceptions.ConnectionDroppedError(
"transport disconnected"))
else:
logger.warning("{}: disconnection was unexpected".format(
self.name))
# Regardless of cause, it is now a ConnectionDroppedError
e = transport_exceptions.ConnectionDroppedError(cause=cause)
handle_exceptions.handle_background_exception(e)