def connect(self):
"""
Connect the client to IBM Watson IoT Platform using the underlying Paho MQTT client
# Raises
ConnectionException: If there is a problem establishing the connection.
"""
self.logger.debug(
"Connecting... (address = %s, port = %s, clientId = %s, username = %s)"
% (self.address, self.port, self.clientId, self.username))
try:
self.connectEvent.clear()
self.logger.debug(
"Connecting with clientId %s to host %s on port %s with keepAlive set to %s"
% (self.clientId, self.address, self.port, self.keepAlive))
self.client.connect(self.address,
port=self.port,
keepalive=self.keepAlive)
self.client.loop_start()
if not self.connectEvent.wait(timeout=60):
self.client.loop_stop()
self._logAndRaiseException(
ConnectionException(
"Operation timed out connecting to IBM Watson IoT Platform: %s"
% (self.address)))
except socket.error as serr:
self.client.loop_stop()
self._logAndRaiseException(
ConnectionException(
"Failed to connect to IBM Watson IoT Platform: %s - %s" %
(self.address, str(serr))))
def _onConnect(self, mqttc, userdata, flags, rc):
"""
Called when the broker responds to our connection request.
The value of rc determines success or not:
0: Connection successful
1: Connection refused - incorrect protocol version
2: Connection refused - invalid client identifier
3: Connection refused - server unavailable
4: Connection refused - bad username or password
5: Connection refused - not authorised
6-255: Currently unused.
"""
if rc == 0:
self.connectEvent.set()
self.logger.info("Connected successfully: %s" % (self.clientId))
# Restoring previous subscriptions
with self._subLock:
if len(self._subscriptions) > 0:
for subscription in self._subscriptions:
# We use the underlying mqttclient subscribe method rather than _subscribe because we are
# claiming a lock on the subscriptions list and do not want anything else to modify it,
# which that method does
(result, mid) = self.client.subscribe(
subscription,
qos=self._subscriptions[subscription])
if result != paho.MQTT_ERR_SUCCESS:
self._logAndRaiseException(
ConnectionException(
"Unable to subscribe to %s" %
subscription))
self.logger.debug("Restored %s previous subscriptions" %
len(self._subscriptions))
elif rc == 1:
self._logAndRaiseException(
ConnectionException("Incorrect protocol version"))
elif rc == 2:
self._logAndRaiseException(
ConnectionException("Invalid client identifier"))
elif rc == 3:
self._logAndRaiseException(
ConnectionException("Server unavailable"))
elif rc == 4:
self._logAndRaiseException(
ConnectionException("Bad username or password: (%s, %s)" %
(self.username, self.password)))
elif rc == 5:
self._logAndRaiseException(
ConnectionException(
"Not authorized: s (%s, %s, %s)" %
(self.clientId, self.username, self.password)))
else:
self._logAndRaiseException(
ConnectionException("Unexpected connection failure: %s" %
(rc)))