def stopkill(self):
"""Called to stop all scheduled RepeatedFunctions"""
try:
self.stop_event.set() #no more scheduling new events
while len(self.running_rep_functions[:]) != 0:
for repfunc_thread in self.running_rep_functions[:]:
repfunc_thread.stop_event.set(
) #stop this RepeatedFunction
for repfunc_thread in self.running_rep_functions[:]:
if not repfunc_thread.is_alive():
self.running_rep_functions.remove(repfunc_thread)
logger.debug("removed {}".format(repfunc_thread))
# now self.running_rep_functions is empty
self.stop_event.clear()
except Exception as e:
logger.error("Unexpected Error, sending to cloud {}".format(e))
formatted_publish_message(
topic=TOPIC_STATE,
payload=
"Error scheduling old timing events, consider restarting device: {} "
.format(e),
c_queue=pub_queue)
def config_on_message(self, unused_client, unused_userdata, message):
"""Callback when the device receives a config message on the config subscription."""
try:
config_payload = str(message.payload.decode('utf-8'))
if config_payload not in self.last_messages_payloads:
"""if config message received that was not received earlier"""
logger.info("new config message received")
self.last_messages_payloads.append(config_payload)
self.last_messages_payloads = self.last_messages_payloads[
-5:] #keep only most recent messages
#[Start Config Update]
#check_configuration_message(config_payload, self.scheduler_obj, self.modbus_reader_obj, self.publishing_queue) #gets final result update implemented [True/False] and log
#[End Config Update]
t = threading.Thread(target=check_configuration_message,
args=(
config_payload,
self.scheduler_obj,
self.modbus_reader_obj,
self.publishing_queue,
))
t.setDaemon = True
t.start()
else:
"""if config message received that was received earlier, e.g. through QoS1 MQTT Subscription"""
logger.info("Existing config message received again")
except Exception as e:
logger.error("Error in Paho Callback config_on_message {}",
format(e))
def on_message(self, unused_client, unused_userdata, message):
"""Callback when the device receives a message on a subscription."""
try:
payload = str(message.payload.decode('utf-8'))
logger.info(
' Received message \'{}\' on topic \'{}\' with Qos {}'.format(
payload, message.topic, str(message.qos)))
except Exception as e:
logger.error("Error in Paho Callback on_message {}", format(e))
def on_disconnect(self, unused_client, unused_userdata, rc):
"""Paho callback for when a device disconnects."""
try:
logger.warning('on_disconnect callback reason: {}: {}'.format(
rc, mqtt.error_string(rc)))
# Since a disconnect occurred, the next loop iteration will wait with
# exponential backoff.
self.should_backoff = True
except Exception as e:
logger.error("Error in Paho Callback on_disconnect{}", format(e))
def connect_serial(self):
"connect the serial port and modbus rtu master over serial port"
logger.debug("calling connect serial")
try:
if self.serial_port != "undefined": #if initialisized
self.serial_port.close()
logger.debug("serial port closed successfully")
except:
pass
try:
self.serial_connected = False
self.master_status = self.max_master_attemps
self.serial_port = serial.Serial(
port=self.port_config["port"],
baudrate=self.port_config["baudrate"],
bytesize=self.port_config["databits"],
parity=self.port_config["parity"],
stopbits=self.port_config["stopbits"],
xonxoff=0)
logger.debug("connected serial")
self.master = modbus_rtu.RtuMaster(self.serial_port)
self.master.set_timeout(self.port_config["timeout_connection"]
) #max waittime for modbus answers
self.master.set_verbose(
False) #if True, log additional modbus info
#Successfull, set flags
logger.debug("connected rtu master")
self.serial_connected = True
self.master_status = 0
with self.timing_queue.mutex: #reset timing events queue
self.timing_queue.queue.clear()
except Exception as e:
time.sleep(3)
logger.error(
"ERROR Serial Port connection not successful{}".format(e))
self.serial_connected = False
def on_connect(self, unused_client, unused_userdata, unused_flags, rc):
try:
"""Callback for when a device connects."""
logger.info('on_connect:{}'.format(mqtt.connack_string(rc)))
# After a successful connect, reset backoff time and stop backing off.
self.should_backoff = False
self.minimum_backoff_time = 2
logger.info('Subscribing to {} and {}'.format(
self.mqtt_command_topic, self.mqtt_config_topic))
# Subscribe to the config topic, QoS 1 enables message acknowledgement.
self.client.subscribe(self.mqtt_config_topic, qos=1)
# Subscribe to the commands topic, QoS not used
self.client.subscribe(self.mqtt_command_topic, qos=0)
except Exception as e:
logger.error("Error in Paho Callback on_connect{}", format(e))
def run(self):
self.alive = True
while True: #Endless Loop of reconfigure, connect_serial and read_modbus_event
logger.debug("RESTART the Modbus reader")
try:
self.reconfigure()
while self.alive == True: # do until stopkill is callled
self.connect_serial() #serial connected
self.read_modbus_event()
while self.alive == False: # do until startup is callled
logger.debug("Modbus reader haltering")
time.sleep(2)
except Exception as ex:
logger.error("Unexpected run modbus error {}".format(ex))
time.sleep(1)
def read_modbus_event(self):
"""read operations of the timing_queue with the Modbus RTU Master and Execute them with """
logger.debug("calling read_modbus_event")
while self.serial_connected and self.alive and self.master_status < self.max_master_attemps - 1:
request = self.timing_queue.get(
) #blocking call until new request is received
if self.alive == False: #discontinue if function is wished to be stopped
self.timing_queue.task_done()
break
slave_id = request["slave_id"]
startadress = request["startadress"]
function_code = request["function_code"]
display_name = request["display_name"]
result = (99999, "modbus_request_not_possible") #default
try:
if "quantity_of_x" in request:
result = self.master.execute(
slave=slave_id,
function_code=function_code,
starting_address=startadress,
quantity_of_x=request["quantity_of_x"]) #read
elif "output_value" in request:
result = self.master.execute(
slave=slave_id,
function_code=function_code,
starting_address=startadress,
output_value=request["output_value"]) #write
logger.debug(
"slave no {}, starting_adress {} with name {} and {} ".
format(slave_id, startadress, display_name, str(result)))
self.master_status = 0 #successfull read, reset to 0
except ModbusError as exc:
self.master_status = self.master_status + 1 #unsuccessfull, increase the status
logger.warning(
"ModbusError in read_modbus_event {}".format(ex))
except Exception as ex: #other error, like serial port etc.
logger.warning(
"Unexpected error in read_modbus_event {}".format(ex))
self.master_status = self.master_status + 5 #unsuccessfull, increase the status
self.serial_connected = False
payload = {
"na": display_name,
"res": result,
"sl": slave_id,
"time": time.time()
}
formatted_publish_message(topic=TOPIC_EVENT,
payload=payload,
c_queue=self.publishing_queue)
self.timing_queue.task_done()
logger.warning("Disconnected the Modbus, restarting")
try:
if self.serial_port != "undefined": #if not just initialisized
self.serial_port.close()
except Exception as ex:
logger.error("error closing serial port: {}".format(ex))
def startup(self):
"""Start or Restart the Scheduling events"""
#Step 1: Figure out what current setup_modbus.json is and its slaveconfig
unused_port_config, slaveconfig = read_setup(
self.publishing_queue) #wait to get newest setup
try:
while not self.stop_event.is_set():
#Step 2: For every operation in slaveconfig: find out details
for slave_name in slaveconfig: #looping through all exisiting slaves
operations = slaveconfig[slave_name]["operations"]
slave_id = slaveconfig[slave_name]["slave_id"]
for operation in operations: #looping for all operations of a specific slave
#[Start get Information of Operation]
op = operations[operation]
interval = (op["sampling_interval"]
) #interval for Scheduling events
process_request = {
"slave_id": slave_id,
"startadress": op["startadress"],
"function_code": op["function_code"],
"display_name": op["display_name"],
}
if "quantity_of_x" in op:
process_request["quantity_of_x"] = op[
"quantity_of_x"]
elif "output_value" in op:
process_request["output_value"] = op[
"output_value"]
else:
logger.error(
"FATAL ERROR, no output value or quantity_of_x {}"
.format(process_request))
#[End get Information of Operation]
self.stop_event.wait(
self.timeout_between_functions
) #timeout, so differet request will be executed at different times
if self.stop_event.is_set():
logger.warning(
"Error: unwanted break in scheduling new RepeatedFunctions"
)
return
#Step 3: For a specific operation schedule a specific RepeatedFunction every interval seconds
#[Start Schedule new RepeatedFunction]
rf = RepeatedFunction(interval, self.query_task,
(self, process_request))
rf.setDaemon = True
rf.start()
self.running_rep_functions.append(rf)
logger.debug(
"scheduleded {} \t at interval {} ".format(
process_request,
(str(interval) +
"s") if interval != 0 else "once occuring"))
#[End Schedule new RepeatedFunction]
logger.debug("ending this scheduler thread {}".format(
self.running_rep_functions))
return
except Exception as e: #should in no case occur
logger.error(
"Error scheduling new timing events, consider restarting device: {}"
.format(e))
formatted_publish_message(
topic=TOPIC_STATE,
payload=
"Error scheduling new timing events, consider restarting device: {} "
.format(e),
c_queue=pub_queue)
def publish_data(self):
"""Publish data from the publishing queue via MQTT
start_new_connection and initial_start_client must be run first.
Will do nothing if self.connection_working and self.run_publish are not set to true beforehand.
"""
try:
while self.connection_working == True and self.run_publish == True:
# [Start Queue message from queue]
while True:
try:
#[Start Do Exponential Backoff and Reconnect]
if self.should_backoff and (
datetime.datetime.utcnow() -
self.last_client_restart).seconds > 5:
logger.info("Backoff detected, reconnect")
self.do_exponential_backoff()
self.start_new_connection()
#[End Do Exponential Backoff and Reconnect]
publish_request = self.publishing_queue.get(
timeout=1
) #wait for newest message from publishing_queue that is queued to be puplished
break #if element was in queue
except queue.Empty:
pass
sub_topic = publish_request["sub_topic"]
payload = publish_request["payload"]
qos = int(publish_request["qos"])
mqtt_topic = "/devices/{}/{}".format(
DEVICE_ID, sub_topic) #where message is published
# [End message from queue]
# [START jwt_refresh]
seconds_since_issue = (datetime.datetime.utcnow() -
self.jwt_iat).seconds
if seconds_since_issue + 60 >= int(60 * JWT_EXPIRES_MINUTES):
logger.info(
"Refreshing JWT token and connection after {}s".format(
seconds_since_issue))
self.start_new_connection()
# [END jwt_refresh]
# [START Precaution before publish on recent opened connection]
elapsed_seconds_since_restart = (
datetime.datetime.utcnow() -
self.last_client_restart).seconds
if elapsed_seconds_since_restart < 20: #if paho mqtt not ready
if elapsed_seconds_since_restart < 5:
logger.debug(
"MQTT just after connection restart, pausing message send for 5 seconds"
)
time.sleep(max(0, 5 - elapsed_seconds_since_restart)
) #up to 5 seconds sleep
if qos == 0:
logger.debug("Set message from qos 0 to qos 1")
qos = 1 #set to qos 1 until stable connection and fully set up
# [END Precaution before publish on recent opened connection]
# [Start State messages delay]
if sub_topic == TOPIC_STATE:
#TOPIC_STATE can be refreshed no more than once per second & 6000 times per minute per project in the Google Cloud, optimum once each 5 or 10 seconds max.
time_difference_state = (
datetime.datetime.utcnow() -
self.last_state_message_queued).seconds
if 0 <= time_difference_state < 5:
logger.info("State message, Sleeping for {}".format(
5 - time_difference_state))
time.sleep(max(0, 5 - time_difference_state))
self.last_state_message_queued = datetime.datetime.utcnow()
# [End State messages delay]
self.client.publish(
mqtt_topic, payload, qos=qos,
retain=True) # Publish payload to the MQTT topic.
self.publishing_queue.task_done()
except Exception as e:
logger.error(
'An error occured during publishing data {}'.format(e))
self.connection_working == False
def on_publish(self, unused_client, unused_userdata, unused_mid):
"""Paho callback when a message is sent to the broker."""
try:
logger.info('on_publish')
except Exception as e:
logger.error("Error in Paho Callback on_publish {}", format(e))
