I'd like to be able to pull an IoT Edge device's module twin via an HTTPS GET request just like the Azure Portal does. In the portal, I see this firing...
https://my-hub.azure-devices.net/twins/my-device/modules/my-module?api-version=2020-09-30&_=164130947416
...and returning JSON. I'd like to do the same outside of the portal (like in Postman or something).
Obviously, by being logged in to the portal, I have credentials that permit that.
I've tried creating a Shared Access Signature and using it as a header like so...
"Authorization": "SharedAccessSignature sr=my-hub.azure-devices.net&sig=...
...but I get back ErrorCode:IotHubUnauthorizedAccess;Unauthorized
Am I missing something? Maybe a step where I use that SAS to get some additional credential or something?
Or maybe I can't create a SAS that works with any device-id?
In the end, I'd just like to be able to GET the reported properties for a module twin from any of my IoT Hub devices. No setting, no subscribing.
The API you're referring to is documented here. You're doing the right thing, but perhaps your method of creating a Shared Access Signature isn't working. One easy way to create a valid SAS token is by using the az cli command: az iot hub generate-sas-token -n <iot-hub-name>. By default it will create a token for the iothubowner policy, which should give you access to the module twin.
I used Postman, with the Authorization header as you mentioned to check the twin of my device $edgeHub module:
https://<my-iot-hub>.azure-devices.net/twins/<device-id>/modules/$edgeHub?api-version=2020-05-31-preview