Client - Agent Information Reporting Error: "DEVICE_GROUP_NOT_FOUND" - mongodb

Question

It appears that IoT-Agent isn't receiving measures, Agent's log says device group not found [MONGO-ALARM]. Does anyone understand what this error means or how to fix it?
Agent's log:
time=2018-12-10T16:48:24.824Z | lvl=DEBUG | corr=n/a | trans=n/a | op=LWM2MLib.COAPRouter | msg=Handling request with method [POST] on url [/rd/1] with messageId [24748]
time=2018-12-10T16:48:24.826Z | lvl=DEBUG | corr=n/a | trans=n/a | op=LWM2MLib.UpdateRegistration | msg=Handling update registration request
time=2018-12-10T16:48:24.826Z | lvl=DEBUG | corr=n/a | trans=n/a | op=LWM2MLib.COAPUtils | msg=Extracting query parameters from request
time=2018-12-10T16:48:24.827Z | lvl=DEBUG | corr=n/a | trans=n/a | op=LWM2MLib.UpdateRegistration | msg=Updating device register with lifetime [undefined] and address [193.136.33.222].
{"op":"IOTAgent.LWM2MHandlers","time":"2018-12-10T16:48:24.827Z","lvl":"DEBUG","msg":"Handling update registration of the device"}
time=2018-12-10T16:48:24.829Z | lvl=DEBUG | corr=54b6621d-65fd-43db-ac9b-fade34e4d947 | trans=54b6621d-65fd-43db-ac9b-fade34e4d947 | op=IoTAgentNGSI.MongoDBGroupRegister | srv=n/a | subsrv=n/a | msg=Looking for group params ["resource","apikey"] with queryObj {} | comp=IoTAgent
time=2018-12-10T16:48:24.835Z | lvl=DEBUG | corr=54b6621d-65fd-43db-ac9b-fade34e4d947 | trans=54b6621d-65fd-43db-ac9b-fade34e4d947 | op=IoTAgentNGSI.MongoDBGroupRegister | srv=n/a | subsrv=n/a | msg=Device group for fields [["resource","apikey"]] not found: [{}] | comp=IoTAgent
**time=2018-12-10T16:48:24.836Z | lvl=ERROR | corr=54b6621d-65fd-43db-ac9b-fade34e4d947 | trans=54b6621d-65fd-43db-ac9b-fade34e4d947 | op=IoTAgentNGSI.Alarms | srv=n/a | subsrv=n/a | msg=Raising [MONGO-ALARM]: {"name":"DEVICE_GROUP_NOT_FOUND","message":"Couldn\t find device group","code":404} | comp=IoTAgent**
time=2018-12-10T16:48:24.836Z | lvl=DEBUG | corr=54b6621d-65fd-43db-ac9b-fade34e4d947 | trans=54b6621d-65fd-43db-ac9b-fade34e4d947 | op=IoTAgentNGSI.MongoDBDeviceRegister | srv=n/a | subsrv=n/a | msg=Looking for device with id [raspiSensorTV]. | comp=IoTAgent
time=2018-12-10T16:48:24.843Z | lvl=ERROR | corr=54b6621d-65fd-43db-ac9b-fade34e4d947 | trans=54b6621d-65fd-43db-ac9b-fade34e4d947 | op=IoTAgentNGSI.Alarms | srv=n/a | subsrv=n/a | msg=Releasing [MONGO-ALARM] | comp=IoTAgent
{"op":"IOTAgent.LWM2MHandlers","time":"2018-12-10T16:48:24.843Z","lvl":"DEBUG","msg":"Preregistered device found."}
time=2018-12-10T16:48:24.844Z | lvl=DEBUG | corr=n/a | trans=n/a | op=LWM2MLib.UpdateRegistration | msg=Update registration request ended successfully
{"time":"2018-12-10T16:48:24.894Z","lvl":"DEBUG","msg":"Observers created successfully."}
The log above appears everytime the device signals to have sent a measure, but my query for provisioned devices returns empty list:
curl -X GET \
'http://localhost:4041/iot/devices' \
-H 'fiware-service: smartGondor' \
-H 'fiware-servicepath: /gardens'
{"count":0,"devices":[]}
Any idea please?

Answer 1

Your request is showing that no devices have been successfully provisioned yet.
It is likely that you have either not provisioned a service group for your IoT Agent or not provisioned the device itself. If a measurement is received before a service group has been provisioned then the IoT Agent will not know how devices identify themselves or where to persist the measurements.
You can provision a service group in multiple ways, but one method would be as follows:
curl -iX POST \
'http://iot-agent:4041/iot/services' \
-H 'Content-Type: application/json' \
-H 'fiware-service: <xxxxxxx>' \
-H 'fiware-servicepath: <yyyyy>' \
-d '{
"services": [
{
"apikey": "<api-key>",
"cbroker": "http://orion:1026",
"entity_type": "Thing",
...etc
}
]
}'
Thereafter any unknown device responding with the correct <api-key> will create an entity called Thing.
Of course if you want to be more specific you can provision the device as shown:
curl -iX POST \
'http://iot-agent:4041/iot/devices' \
-H 'Content-Type: application/json' \
-H 'fiware-service: <xxxxxxx>' \
-H 'fiware-servicepath: <yyyyy>' \
-d '{
"devices": [
{
"device_id": "motion001",
"entity_name": "urn:ngsd-ld:Motion:001",
"entity_type": "Motion",
"attributes": [
{ "object_id": "c", "name": "count", "type": "Integer" }
],
}
]
}
'
This ensures that a device identifying as motion001 will be stored as a Motion entity and various mappings will take place.