def create_devices_and_find_endpoints(stations):
'''
Creates all stations that currently do not exist in the IoT Hub as new devices.
Adds 'hub_endpoint' attribute to all stations (no matter whether it already exists in the hub or not)
which can be used to send messages to the stations
'''
# TODO: make create_and_get_devices indepentent of stations to allow reusing it in other iot use cases
connection_string = os.getenv("IOT_HUB_CONNECTION_STRING")
host = os.getenv("IOT_HUB_HOSTNAME")
try:
iot_manager = IoTHubRegistryManager(connection_string)
# note that 'get_devices() only works for cnt of devices <= 1000,
# otherwise querying keys is more complex AND time consuming
dev_list = iot_manager.get_devices()
# convert list to dict for easy access
devices = {
dev_list[i].device_id: dev_list[i]
for i in range(0, len(dev_list))
}
del dev_list
new_devices = []
for station in stations.values():
device_name = station.get('station_name',
station.get('station_id', ''))
device = devices.get(device_name, None)
if device != None:
# if device already exists, only add its endpoint to the station
station['hub_endpoint'] = get_endpoint_uri(
host, device_name,
device.authentication.symmetric_key.primary_key)
else:
# otherwise create device object and add its endpoint to station
# the actual creation of the device in the hub happens at the end in a bulk
new_device, new_endpoint = create_device(device_name, host)
station['hub_endpoint'] = new_endpoint
new_devices.append(new_device)
# splitting operations in chunks prevents to large messages
# that raise exceptions
insert_chunks = chunks(new_devices, __CHUNK_SIZE)
for chunk in insert_chunks:
iot_manager.bulk_create_or_update_devices(chunk)
except Exception as ex:
print("Unexpected error {0}".format(ex))
def delete_all_devices():
'''
Deletes all devices in the Azure IoT Hub. This function is not
used in the Azure Function but can be useful, if you want to reset
the Azure Environment.
'''
connection_string = os.getenv("IOT_HUB_CONNECTION_STRING")
iot_manager = IoTHubRegistryManager(connection_string)
dev_list = iot_manager.get_devices()
delete_list = []
for d in dev_list:
dev = ExportImportDevice(id=d.device_id)
dev.import_mode = "delete"
delete_list.append(dev)
# splitting operations in chunks prevents to large messages
# that raise exceptions
del_chunks = chunks(delete_list, __CHUNK_SIZE)
for chunk in del_chunks:
iot_manager.bulk_create_or_update_devices(chunk)
replaced_twin = iothub_registry_manager.replace_twin(device_id, new_twin)
print(replaced_twin)
print("")
# Update twin
twin_patch = Twin()
twin_patch.properties = TwinProperties(desired={"telemetryInterval": 3000})
updated_twin = iothub_registry_manager.update_twin(device_id, twin_patch,
twin.etag)
print(updated_twin)
print("The twin patch has been successfully applied")
# Get devices
max_number_of_devices = 10
devices = iothub_registry_manager.get_devices(max_number_of_devices)
if devices:
x = 0
for d in devices:
print_device_info("Get devices {0}".format(x), d)
x += 1
else:
print("No device found")
# Delete the device
iothub_registry_manager.delete_device(device_id)
print("GetServiceStatistics")
registry_statistics = iothub_registry_manager.get_service_statistics()
print(registry_statistics)
