Lightweightm2m-iotagent can't connect to mongodb

Question

I am setting up a demo on IoT using LWM2M device on FIWARE platform (using Orion CB). However, the lightweightm2m-iotagent cannot connect to the mongodb. Any idea why this happen? Below is the error I am getting:

{
    "message": "Cannot read property 'findOne' of undefined",
    "name": "TypeError"
}

I am using docker-compose file (below) to start all services.

version: "3.1"

services:
        mongo:
                image: mongo:3.2
                command: --nojournal
                ports: 
                 - "27017:27017"
                expose:
                 - "27017"
        orion:
                image: fiware/orion
                links:
                 - mongo
                ports: 
                 - "1026:1026"
                command: -dbhost mongo -logLevel DEBUG
                depends_on:
                 - mongo
                expose: 
                 - "1026"
        lightweightm2m-iotagent:
                image: telefonicaiot/lightweightm2m-iotagent
                hostname: idas
                links:
                 - orion
                expose: 
                 - "4041"
                 - "5684"
                ports: 
                 - "4041:4041"
                 - "5684:5684/udp"
        mosquitto:
                image: ansi/mosquitto
                ports: 
                 - "1883:1883"
                expose: 
                 - "1883"

Answer 1

This issue was solved by adding the following (in lightweightm2m-iotagent definition)

environment: 
   - IOTA_MONGO_HOST=mongo