node-red-contrib-mqtt-gem

Add little features to Standard MQTT nodes for Node-RED using environment variables support and dynamic configuration capabilities.

Library extension developed by GEM srl - Sant'Agata sul Santerno (RA), Italy derived from Original Node-red core library

🚀 Features

node-red-contrib-mqtt-gem extends the standard Node-RED MQTT nodes with powerful dynamic configuration capabilities:

✅ Dynamic Broker Control

• Enable/Disable connections dynamically via environment variable (use "Auto connect" to enable/disable)
• Automatic connection management based on runtime configuration
• Visual status indicators (disabled nodes show "disabled" in gray)

🌍 Environment Variables Support

• Port Configuration: Use any environment variable for port numbers
• Auto-Connect Control: Dynamic connection behavior via custom variable names
• TLS Configuration: Runtime TLS enablement via any environment variable
• Protocol Version: Support for custom MQTT protocol versions (3.1, 3.1.1, 5.0)
• Complete Broker Settings: All broker parameters can be configured via any environment variable names

🔧 Enhanced Protocol Support

• MQTT v3.1 (legacy)
• MQTT v3.1.1 (standard)
• MQTT v5.0 (latest)
• Custom Protocol Selection: Text input for environment variable-based protocol selection

🎯 Smart Node Behavior

• Disabled brokers prevent IN/OUT nodes from processing messages
• Visual feedback with status indicators
• Seamless integration with existing Node-RED flows
• No conflicts with core MQTT nodes

📦 Installation

Via Node-RED Palette Manager (Recommended)

1. Open Node-RED editor
2. Go to Menu → Manage palette
3. Select Install tab
4. Search for node-red-contrib-mqtt-gem
5. Click Install

Via npm

npm install node-red-contrib-mqtt-gem

Manual Installation

cd ~/.node-red
npm install node-red-contrib-mqtt-gem

🔧 Configuration

Environment Variables Setup

You can use ANY variable names you prefer. The examples below use common naming conventions:

# Example with standard names
export MQTT_HOST="broker.example.com"
export MQTT_PORT="1883"
export MQTT_AUTOCONNECT="true"
export MQTT_USETLS="false"
export MQTT_PROTOCOL="5"

# Example with custom names
export MY_BROKER_ADDRESS="broker.example.com"
export MY_BROKER_PORT="1883"
export ENABLE_MQTT="true"
export USE_SSL="false"
export MQTT_VERSION="5"

# Example with company-specific names
export COMPANY_MQTT_SERVER="internal.company.com"
export PRODUCTION_MQTT_PORT="8883"
export MQTT_CONNECTION_ENABLED="true"

# Start Node-RED
node-red

Docker Configuration

# Dockerfile
FROM nodered/node-red:latest

# Install the plugin
RUN npm install node-red-contrib-mqtt-gem

# Set environment variables (use any names you prefer)
ENV MY_MQTT_HOST=broker.example.com
ENV MY_MQTT_PORT=1883
ENV MQTT_ENABLED=true
ENV USE_TLS=false
ENV PROTOCOL_VERSION=5

Docker Compose

version: '3.8'
services:
  node-red:
    image: nodered/node-red:latest
    ports:
      - "1880:1880"
    environment:
      - MY_MQTT_HOST=broker.example.com
      - MY_MQTT_PORT=1883
      - MQTT_ENABLED=true
      - USE_TLS=false
      - PROTOCOL_VERSION=5
    volumes:
      - node-red-data:/data
    command: >
      bash -c "npm install node-red-contrib-mqtt-gem && 
               npm start -- --userDir /data"

volumes:
  node-red-data:

🎮 Usage Examples

Basic Broker Configuration

Static Configuration:

Server: broker.example.com
Port: 1883
Auto Connect: true
Use TLS: false
Protocol: MQTT V3.1.1

Dynamic Configuration with Environment Variables (use any variable names):

Server: ${MY_BROKER_HOST}
Port: ${MY_BROKER_PORT}
Auto Connect: ${MQTT_ENABLED}
Use TLS: ${USE_SSL_CONNECTION}
Protocol: Custom → ${MQTT_VERSION}

Conditional MQTT Publishing

// In a Function node before mqtt-gem out
if (env.get("MY_MQTT_ENABLED") === "true") {
    return msg; // Send message
} else {
    return null; // Block message
}

Multi-Environment Setup

# Development Environment
export DEV_MQTT_HOST="dev-broker.internal"
export DEV_MQTT_PORT="1883"
export DEV_MQTT_ENABLED="true"

# Production Environment
export PROD_MQTT_HOST="prod-broker.company.com"
export PROD_MQTT_PORT="8883"
export PROD_MQTT_ENABLED="true"
export PROD_USE_TLS="true"

# Staging Environment
export STAGING_BROKER="staging.company.com"
export STAGING_PORT="1883"
export STAGING_CONNECTION="false"  # Disabled in staging

Protocol Version Examples

# MQTT v3.1 (legacy)
export MY_PROTOCOL="3"

# MQTT v3.1.1 (standard)  
export BROKER_PROTOCOL="4"

# MQTT v5.0 (latest)
export MQTT_VERSION="5"

📋 Node Types

mqtt-gem-broker (Configuration Node)

Enhanced broker configuration with environment variable support for all parameters.

mqtt-gem in (Input Node)

MQTT subscriber with dynamic broker configuration. Shows "disabled" status when broker is disabled.

mqtt-gem out (Output Node)

MQTT publisher with dynamic broker configuration. Blocks messages when broker is disabled.

🔍 Environment Variables Reference

Important: You can use any variable names you prefer. The table below shows common examples, but you have complete freedom in naming:

Example Variable	Description	Default	Example Values
MY_MQTT_HOST	Broker hostname/IP	localhost	broker.example.com
BROKER_PORT	Broker port	1883	1883, 8883
MQTT_ENABLED	Auto-connect on startup (enable/disable connection and nodes)	true	true, false
USE_SSL	Enable TLS/SSL	false	true, false
PROTOCOL_VERSION	MQTT protocol version	4	3, 4, 5

Configuration Examples:

# Company-specific naming
export COMPANY_MQTT_BROKER="internal.company.com"
export COMPANY_MQTT_PORT="1883"

# Project-specific naming  
export PROJECT_A_BROKER="project-a.broker.com"
export PROJECT_A_ENABLED="true"

# Environment-specific naming
export PROD_MQTT_HOST="prod-broker.com"
export DEV_MQTT_HOST="dev-broker.com"

🧪 Testing

Test Flow Example

1. Create test brokers:

   • Active broker with MY_MQTT_ENABLED=true
   • Disabled broker with MQTT_CONNECTION=false

2. Add MQTT nodes:

   • Input nodes for both brokers
   • Output nodes for both brokers

3. Verify behavior:

   • Active broker: nodes work normally
   • Disabled broker: nodes show "disabled" status and don't process messages

Environment Variables Test

# Set test variables (use any names you prefer)
export TEST_MQTT_HOST="test.mosquitto.org"
export TEST_MQTT_PORT="1883" 
export TEST_CONNECTION_ENABLED="true"
export TEST_PROTOCOL_VERSION="5"

# Start Node-RED and verify configuration
node-red

🔧 Development

Local Development Setup

# Clone repository
git clone https://github.com/lucagem/node-red-contrib-mqtt-gem.git
cd node-red-contrib-mqtt-gem

# Install dependencies
npm install

# Setup development environment
npm run dev-setup

# Start development Node-RED instance
npm run dev

Development Commands

# Start development server
npm run dev

# Debug mode
npm run dev-debug

# Run tests (when available)
npm test

📝 Migration from Standard MQTT Nodes

1. Replace node types in your flows:

   • mqtt in → mqtt-gem in
   • mqtt out → mqtt-gem out
   • mqtt-broker → mqtt-gem-broker

2. Update broker configurations to use environment variables:

   • Replace static values with ${VARIABLE_NAME}
   • Set corresponding environment variables

3. Deploy and test the updated flow

❓ Troubleshooting

Common Issues

Q: Nodes show "disabled" status
A: Check that your auto-connect variable (e.g., MY_MQTT_ENABLED) is set to "true" (as string)

Q: Environment variables not resolving
A: Ensure variables are set before starting Node-RED and use correct syntax: ${YOUR_VARIABLE_NAME}

Q: Protocol version not working
A: For custom protocols, select "Custom..." in dropdown and enter ${YOUR_PROTOCOL_VAR} in text field

Q: TLS connection failing
A: Verify your TLS variable (e.g., USE_TLS="true") and correct port (usually 8883 for TLS)

Debug Mode

Enable Node-RED debug logging:

DEBUG=mqtt-gem* node-red

🤝 Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

📄 License

MIT License - see LICENSE file for details.

🔗 Links

• Repository: https://github.com/lucagem/node-red-contrib-mqtt-gem
• Issues: https://github.com/lucagem/node-red-contrib-mqtt-gem/issues
• Node-RED: https://nodered.org
• MQTT.org: https://mqtt.org

📊 Compatibility

• Node-RED: >= 2.0.0
• Node.js: >= 14.0.0
• MQTT: Versions 3.1, 3.1.1, 5.0

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Developed by GEM srl - Sant'Agata sul Santerno (RA), Italy
Author: Luca Tralli