Azure-docs: Transparent gateway pattern device provisioning

[krokoko]

Hello,

I was wondering if there is any guidelines/information/tutorials concerning the provisioning of downstream devices connected to an iot edge gateway in transparent mode (can we use the automatic provisioning samples in Azure IoT SDK C for instance ?). Related tutorial : https://docs.microsoft.com/en-us/azure/iot-edge/how-to-create-transparent-gateway-linux

Thank you !

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Document Details

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• ID: 71acc49c-a23e-493f-c3f5-4ec46846616c
• Version Independent ID: bd3abb8d-1b48-0efd-f6a4-1b3f7a12c039
• Content: Create a transparent gateway with Azure IoT Edge - Linux
• Content Source: articles/iot-edge/how-to-create-transparent-gateway-linux.md
• Service: iot-edge
• GitHub Login: @kgremban
• Microsoft Alias: kgremban

[DiegoRamirez-MSFT]

hello @krokoko We are investigating this issue now. Thank you for reporting it

[asergaz]

Hello @krokoko , last time I checked DPS was not integrated with IoT Edge Leaf Devices. I am double checking with product group and if not you can open a new feature request here.

Thank you!

[krokoko]

Hello @sergaz-msft, thank you for the reply. I will wait for your feedback. So if i'm right the only way for now is to use the certificates with the connection string ? Thank you !

[krokoko]

Just to rephraze my question : what is the process to provision a leaf device using a gateway in transparent mode ? As DPS is not available, how can I interact from IoT hub with my device ? The connection string on leaf device is the one from the gateway so i see nowhere the device identity. Thank you !

[kgremban]

Hi @krokoko, yesterday we published a new article specifically about configuring leaf devices to communicate through gateways. Check that out and see if it helps answer some questions: https://docs.microsoft.com/en-us/azure/iot-edge/how-to-connect-downstream-device

For a transparent gateway scenario, the connection string on the leaf device is an IoT Hub connection string that you append the gateway info onto. The leaf device has its own identity with IoT Hub, and can receive direct methods or device twin updates as usual. This info is summarized in the conceptual article, https://docs.microsoft.com/en-us/azure/iot-edge/iot-edge-as-gateway#cheat-sheet.

[krokoko]

Hello @kgremban ,

Thank you for the links. I already have a system running which is build in the same way that the tutorial explains: a downstream device is connected to an edge gateway (both have their identities in IoT Hub), and the device stream data on a regular basis. This is working fine.

My question is about eventual guidelines/support about putting in production this architecture, as some features are not supported, everything seems to be manual for now.

Also, do you have a list of supported features of the azure iot c sdk for a device communicating with an edge device in transparent mode ? As far as I see now, DPS is not available neither upload of files, but is there anything else ?

Thank you !

[chipalost]

Hi @krokoko, provisioning leaf devices that connect to an Edge device is something that we're investigating. What is your scenario?

1. Leaf devices connects to the internet, uses DPS to provision it's own device identity, and is also told the Edge device to which it should connect as a transparent gateway.
2. Leaf device does not have connectivity and instead connects to Edge device, the Edge device then provides connectivity to DPS for the leaf device, the leaf device then uses that access to provision it's device identity and connect to IoT Hub through the Edge device.

[krokoko]

Hello @chipalost ,

Thank you for the answer. My scenario would be the second one, where my device will not have connectivity and will connect directly to the edge gateway. Is it today a supported feature or it's under discussion ? Thanks !

[chipalost]

Doesn't this reduce the value of DPS? The first value of DPS is that at time of manufacturing you have one global endpoint to burn into your devices. When the device boots it can use that endpoint to go determine it's identity.
You've lost the global endpoint in your scenario. You have no idea to which gateway the device will connect at time of manufacturing. You can only add this to the device once you've determined to where the device will be deployed. Why not provision the device identity and add it to the device at the same time when you add the gateway location?

[krokoko]

Hello @chipalost ,

Ok make sense, thank you for the clarification :)