Python and requesting device details with chirpstack-api failed

ChirpStack (v4)
1

I try to read my devices with python and the chirpstack-api library. I am successful in requesting applications, device_grofiles, gateways, list from devices in an application but if I want to request details from a specifig device I get an error.

This is a working code for requesting applications

import grpc
from chirpstack_api import api as chirpstack


with open(chirpstack_pem, "rb") as f:
    credentials = grpc.ssl_channel_credentials(f.read())
channel = grpc.secure_channel(chirpstack_server, credentials)
auth_token = [("authorization", "Bearer %s" % chirpstack_token)]


if __name__ == "__main__":
    client = chirpstack.ApplicationServiceStub(channel)
    req = chirpstack.ListApplicationsRequest()
    req.limit = 10 #mandatory if you want details
    req.offset = 0
    req.tenant_id = tenant_id
    resp = client.List(req, metadata=auth_token)
    print(resp)

Here the code to request a single device

import grpc
from chirpstack_api import api as chirpstack


with open(chirpstack_pem, "rb") as f:
    credentials = grpc.ssl_channel_credentials(f.read())
channel = grpc.secure_channel(chirpstack_server, credentials)
auth_token = [("authorization", "Bearer %s" % chirpstack_token)]


if __name__ == "__main__":
    client = chirpstack.DeviceServiceStub(channel)
    req = chirpstack.GetDeviceRequest()
    req.dev_eui = "343233386B376510"
    resp = client.List(req, metadata=auth_token)
    print(resp)

And this is the error I get:

Traceback (most recent call last):
  File "C:\Users\ckroon\PycharmProjects\chripstack\chirpstack_device.py", line 21, in <module>
    resp = client.List(req, metadata=auth_token)
  File "C:\Users\ckroon\PycharmProjects\chripstack\venv\lib\site-packages\grpc\_channel.py", line 1160, in __call__
    return _end_unary_response_blocking(state, call, False, None)
  File "C:\Users\ckroon\PycharmProjects\chripstack\venv\lib\site-packages\grpc\_channel.py", line 1003, in _end_unary_response_blocking
    raise _InactiveRpcError(state)  # pytype: disable=not-instantiable
grpc._channel._InactiveRpcError: <_InactiveRpcError of RPC that terminated with:
	status = StatusCode.INTERNAL
	details = "failed to decode Protobuf message: ListDevicesRequest.limit: invalid wire type: LengthDelimited (expected Varint)"
	debug_error_string = "UNKNOWN:Error received from peer  {grpc_message:"failed to decode Protobuf message: ListDevicesRequest.limit: invalid wire type: LengthDelimited (expected Varint)", grpc_status:13, created_time:"2024-02-09T12:59:42.8224533+00:00"}"
>

Process finished with exit code 1

What could I do to get the correct information? I have the same issue with requesting the device key’s.

2

Hello, I think there’s a missing step in retrieving a particular device.
An application can contain multiple devices, so we would need a function to retrieve the list of devices within an application using:

req = chirpstack.ListDevicesRequest()
...
resp = client.List(req, metadata=auth_token)

Then, subsenquently, to obtain a particular device:

client = chirpstack.DeviceServiceStub(channel)
req = chirpstack.GetDeviceRequest()
req.dev_eui = "343233386B376510"
resp = client.Get(req, metadata=auth_token)
print(resp)

In your code to retrieve a particular device, you use client.List , I think it should be client.Get .

3

Thanks for the fast reaction. It was indeed the problem with “client.Get” instead if “client.List”