Authenticating `IoTHubRegistryManager` using the `from_token_credential` constructor

Problem

• Hi azure team; we have a need to manage several IoT hubs; sending cloud to device messages for eg. So far, we have been using the from_connection_string constructor to do this. However this is a bit clunky as it requires us to have the connection string encoded as a secret for each of the IoT hubs.

• We are instead hoping to use from_token_credential to achieve authentication to all the IoT hubs within a subscription.

Attempt and error faced

We are following the instructions as given here to try out C2D messaging for a simulated device; the only difference being

# This line is removed
registry_manager = IoTHubRegistryManager(CONNECTION_STRING)

# This is added
from azure.identity import EnvironmentCredential
credential = EnvironmentCredential()
registry_manager = IoTHubRegistryManager.from_token_credential(
            url="azure-simlab1.azure-devices.net",
            token_credential=credential.get_token(os.environ.get("scopes")),
        ) 

Upon running the command; it either

• Throws when an invalid scope is passed;
• Or just hangs; the simulated device does not receive a message.
• It works perfectly fine if we switch back to the connection string method.

Question

• What is the correct scope for such a request?
• Is the EnvironmentCredential the correct approach?

Thanks! Sahil

[sgoyal1012]

@vishnureddy17 that worked! Thanks for the quick turnaround, really appreciate it 😃

Here is the code that worked

credential = EnvironmentCredential()
registry_manager = IoTHubRegistryManager.from_token_credential(
    url="azure-simlab1.azure-devices.net",
    token_credential=credential,
)

[vishnureddy17]

@sgoyal1012 , if you update your azure-iot-hub to version 2.5.0, you should be able to send the messages. Please let me know if this resolves it, thanks!