Coreflux

Time to Complete: 15 minutes | Difficulty: Beginner friendly

This guide will get you up and running with Coreflux MQTT Broker and MongoDB in under 15 minutes using Docker.

‍

‍

‍Quick Overview

Start MongoDB and Coreflux (2 min)
Connect LoT Notebook (3 min)
Create Data Simulator (2 min)
Create Data Pipeline (5 min)
Verify (3 min)

‍

https://youtu.be/h554ybSD_oc

‍

Prerequisites

Before you start, make sure you have:

Docker installed on your system
Visual Studio Code with LoT Notebook extension
Basic understanding of MQTT and IoT concepts

Need Help? Throughout this tutorial, you can get instant assistance at docs.coreflux.org using the Ask AI feature. Simply describe what you are trying to do, and get personalized guidance on LoT syntax, troubleshooting, and best practices.

Step 1: Start MongoDB and Coreflux MQTT Broker

Create a file called docker-compose.yml and paste the following:

services:
  mongodb:
    image: mongo:latest
    container_name: mongodb
    ports:
      - "27017:27017"
    environment:
      MONGO_INITDB_ROOT_USERNAME: admin
      MONGO_INITDB_ROOT_PASSWORD: coreflux_password
      MONGO_INITDB_DATABASE: iot_data
    volumes:
      - mongodb_data:/data/db
    networks:
      - iot_network

  coreflux:
    image: coreflux/coreflux-mqtt-broker:latest
    container_name: coreflux
    ports:
      - "1883:1883"
      - "1884:1884"
      - "5000:5000"
      - "443:443"
    depends_on:
      - mongodb
    networks:
      - iot_network

volumes:
  mongodb_data:

networks:
  iot_network:
    driver: bridge

Start with:

docker-compose up -d

Stop with:

docker-compose down

Step 2: Connect with LoT Notebook

Open VS Code with LoT Notebook extension
Connect to the broker with these settings:
- Host: localhost
- Port: 1883
- User: root
- Password: coreflux
Create a new file with the .lotnb extension

‍

‍

Tip: You can set the credentials and see connection status in the bottom left bar of VS Code.

Step 3: Create a Simple Data Pipeline

Not familiar with LoT syntax? Visit docs.coreflux.org and use the Ask AI feature for instant explanations and examples.

Create an Action to Generate Data

DEFINE ACTION GenerateData
ON EVERY 10 SECONDS DO
    PUBLISH TOPIC "sensors/temp" WITH RANDOM BETWEEN 20 AND 30

Create a Model to Standardize and Transform Data

DEFINE MODEL SensorData WITH TOPIC "processed/sensor/data"
    ADD "temperature" WITH TOPIC "sensors/temp" AS TRIGGER
    ADD "temp_fahrenheit" WITH (temperature * 9/5 + 32)
    ADD "timestamp" WITH TIMESTAMP "UTC"

Create MongoDB Route

DEFINE ROUTE mongo_route WITH TYPE MONGODB
    ADD MONGODB_CONFIG
        WITH CONNECTION_STRING "mongodb://admin:coreflux_password@mongodb:27017/iot_data?authSource=admin"
        WITH DATABASE "iot_data"

Update Model to Store Data

Add this to the end of your Model:

STORE IN "mongo_route"
    WITH TABLE "MachineProductionData"

Complete Model with storage:

DEFINE MODEL SensorData WITH TOPIC "processed/sensor/data"
    ADD "temperature" WITH TOPIC "sensors/temp" AS TRIGGER
    ADD "temp_fahrenheit" WITH (temperature * 9/5 + 32)
    ADD "timestamp" WITH TIMESTAMP "UTC"
    STORE IN "mongo_route"
        WITH TABLE "MachineProductionData"

Step 4: Verify Everything Works

Check MQTT Messages

Use MQTT Explorer to connect and see live data on topics:

sensors/temp (raw data)
processed/sensor/data (transformed data)

‍

‍

Check MongoDB Storage

Connect with MongoDB Compass using:

mongodb://admin:coreflux_password@localhost:27017

Verify data in the MachineProductionData collection.

‍

‍

Quick Troubleshooting

Cannot connect to MQTT broker?

Check if container is running: docker ps
Check logs: docker logs coreflux

Cannot connect to MongoDB?

Check if container is running: docker ps
Check logs: docker logs mongodb
Verify credentials match

Data not showing in MongoDB?

Verify Route is deployed in LoT Notebook
Check Model has STORE IN clause
Check MongoDB connection string uses correct hostname

Next Steps

Now that you have a working pipeline, you can:

Connect real IoT devices to your MQTT broker using MQTT or Routes to bridge existing systems
Create more complex data transformation models
Set up Grafana for data visualization
Explore other database integrations like PostgreSQL, MySQL, and OpenSearch

Resources

‍

Coreflux + MongoDB Quick Start Guide (15 Minutes)