message_broker_azure_device_client.py

################################################################################
# The MIT License
#
# Copyright (c) 2022-2023, Prominence AI, Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining a
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#!/usr/bin/env python

import sys
from dsl import *

import threading
import time

################################################################################
# This example demonstrates the use of the Device Client Azure protocol to
# to send messages to an Azure IoT Hub. 
################################################################################

protocol_lib = \
    '/opt/nvidia/deepstream/deepstream/lib/libnvds_azure_proto.so'
broker_config_file = \
    '/opt/nvidia/deepstream/deepstream/sources/libs/azure_protocol_adaptor/device_client/cfg_azure.txt'

# Make sure to add your connection string to the cfg_azure.txt, or provide 
# the complete connection string here to override. 
connection_string = None

## 
# Function to be called on connection failure 
## 
def message_broker_connection_listener(client_data, status):
    print('Connection listener called with status:', status)

## 
# Function to be called on send-async result
## 
def message_broker_send_result_listener(client_data, status):
    print('Result listener called with status:', status)

## 
# Thread loop function to periodically send a pre-canned message
## 
def thread_function(name):

    # Simple message to send to the server
    unicode_message = "Hello remote server - edge device is messaging"
    
    # Maximum number of message to send. 
    message_limit = 10
    
    while message_limit:
        retval = dsl_message_broker_message_send_async('message-broker',
            topic = "/dsl/message",
            message = unicode_message.encode('ascii'),
            size = len(unicode_message),
            response_listener = message_broker_send_result_listener,
            client_data = None)
        print('dsl_message_broker_message_send_async returned ', 
            dsl_return_value_to_string(retval))
        time.sleep(2)
        
        message_limit -= 1
        
        

def main(args):

    # Since we're not using args, we can Let DSL initialize GST on first call
    while True:
    
        # Create a new Message Broker with the specs defined above
        retval = dsl_message_broker_new('message-broker', 
            broker_config_file = broker_config_file,
            protocol_lib = protocol_lib,
            connection_string = connection_string)
        if retval != DSL_RETURN_SUCCESS:
            break
            
        # Add a connection listener to be notified on connection failure.
        retval = dsl_message_broker_connection_listener_add('message-broker',
            message_broker_connection_listener, None)    

        # Connect to the remote server
        retval = dsl_message_broker_connect('message-broker')
        if retval != DSL_RETURN_SUCCESS:
            break
            
        # Start the messaging thread to send a number of canned messages.
        send_thread = threading.Thread(target=thread_function, args=(1,))
        
        send_thread.start()
        send_thread.join()
        
        retval = DSL_RETURN_SUCCESS
        break

    # Print out the final result
    print(dsl_return_value_to_string(retval))
    

    # Cleanup all DSL/GST resources
    dsl_delete_all()
    
if __name__ == '__main__':
    sys.exit(main(sys.argv))