Created question in FIWARE Q/A platform on 18-12-2022 at 16:12
Please, ANSWER this question AT https://stackoverflow.com/questions/74842815/iotagent-json-over-mqtt-doesnt-receive-measurements-from-mosquitto

Question:
IoTAgent (JSON) over MQTT doesn't receive measurements from mosquitto

Description:
Goal: to use the IoTAgent (JSON) provided by FIWARE with the MQTT transport protocol. In particular, I would like to provision a service group rather than individual devices, such that anonymous devices can send their measurements to the IoTAgent via the Mosquitto Broker.
Problem: Mosquitto Broker receives messages (sent by an MQTT publisher) but IoTAgent does not. Both are on the same network (I used docker compose), so ruled out this could be the reason of the problem.
The docker-compose.yaml file looks like this:
version: "3.5"
services:
mosquitto:
image: eclipse-mosquitto:1.6.14
hostname: mosquitto
container_name: mosquitto
expose:

• "1883"
• "9001"
  ports:
• "1883:1883"
• "9001:9001"
  networks:
• default

iot-agent:
image: fiware/iotagent-json:latest
hostname: iot-agent
container_name: fiware-iot-agent
depends_on:

• mongo-db
• mosquitto
  networks:
• default
  expose:
• "4041"
  ports:
• "4041:4041"
  environment:
• IOTA_CB_HOST=orion
• IOTA_CB_PORT=1026
• IOTA_CB_NGSI_VERSION=ld
• IOTA_JSON_LD_CONTEXT=http://context/ngsi-context.jsonld
• IOTA_NORTH_PORT=4041
• IOTA_MQTT_HOST=mosquitto
• IOTA_MQTT_PORT=1883
• IOTA_MQTT_QOS=1
• IOTA_MQTT_KEEPALIVE=60
• IOTA_DEFAULT_RESOURCE= # Default is blank. I'm using MQTT so I don't need a resource
• IOTA_REGISTRY_TYPE=mongodb
• IOTA_MONGO_HOST=mongo-db
• IOTA_MONGO_PORT=27017
• IOTA_MONGO_DB=iotagentjson
• IOTA_LOG_LEVEL=DEBUG
• IOTA_TIMESTAMP=true
• IOTA_AUTOCAST=true
• IOTA_FALLBACK_TENANT=openiot

The full docker-compose.yaml is available on GitLab repository.
The service group provisioning is shown below:
{
"services": [
{
"apikey": "4jggokgpepnvsb2uv4s40d59ov",
"entity_type": "TrafficFlowObserved",
"resource": "",
"expressionLanguage": "jexl",
"attributes": [

,

,

]
}
]
}

I expect the IoTAgent to receive measurements from anonymous devices as well as mosquitto. Instead, currently, the IoTAgent does not receive the measurements and gives the following error when I provision the service group: DEVICE_GROUP_NOT_FOUND.
The logs are shown on GitLab repository
I can't figure out the problem.