checking command from orion to iot agent in Fiware - fiware

Question

I've used the FIWARE Orion Context Broker and IoTAgent-UL in my project. I've registered a virual device by sending a Json message carrying the device attributes, the command attributes, device endpoint address and the used protocol (UL2.0).
If I update the command attribute of the device entity in Orion Context Broker, how can i check that the command is sent to the IoTAgent successfully before it is forwarded to the device virtual device itself?
Moreover, can I make the IP address of a Raspberrypi the endpoint itself and assign a port to a device connected to the Raspberrypi? And how could this be done?
Finally, in case I have no physical device could I consider the IoTAgent's address an endpoint to check whether any update on the command attribute in the context broker will be forwarded to that endpoint?
Thanks

Answer 1

There are three ways of checking the update context/command has been sent to the agent, and from the agent or the device:
Check Orion or agent logs.
Check the MQTT broker logs, if you are using MQTT transport.
Check the device itself. If the command was received, you'll be able to see the effects of the command.
Regarding the place a Raspberry Pi may play in an architecture using IoT agents, typically it is used to replace the agent :) I mean, if having a device such as a Raspberry Pi, the usual scenario is to connect to the R-Pi all your sensors and actuators, as if it was a gateway, and then let the R-Pi connect directly to Orion Context Broker by implementing a NGSI client running in the R-Pi. Schematically:
Orion <---> R-Pi + NGSI client <---> sensor/actuator
Nevertheless, I guess you can use the R-Pi as if it was a final device (sensor or actuator) in order to test IoT agents. Regarding how to emulate the final device itself, I guess you'll have to run certain logic in the R-Pi in order to accept the UL messages from the IoT agent/MQTT broker. A simple netcat could help you; more complex emulation services could be run, of course. Schematically:
Orion <----> UL agent <---> R-Pi + netcat
Anyway, please observe always a final device (sensor or actuator) is required, either real, either simulated (running netcat or similar in a R-Pi/server), since the UL agent must have an endpoint where to send the UL payloads.
Orion <---> UL agent <---> R-Pi + netcat OR server + netcat OR real sensor/actuator