Node-RED: Visual Automation for Your Homelab

Node-RED is a flow-based programming tool that lets you wire together APIs, services, and devices with a visual interface. Perfect for homelab automation without writing code. Here's how to get started.

What is Node-RED?

Node-RED is:

• Visual programming - Drag, drop, and connect nodes
• Event-driven - React to events in real-time
• Highly extensible - Thousands of community nodes
• Lightweight - Runs on a Raspberry Pi

Common homelab uses:

• Home automation triggers
• API integrations
• Data transformations
• Alert notifications
• Scheduled tasks

Docker Installation

docker-compose.yml

services:
  node-red:
    image: nodered/node-red:latest
    container_name: node-red
    environment:
      - TZ=America/New_York
    ports:
      - "1880:1880"
    volumes:
      - node_red_data:/data
    restart: unless-stopped

volumes:
  node_red_data:

Access at http://your-server:1880

Your First Flow

Let's create a simple HTTP endpoint that returns system info:

1. Drag an http in node - Set method to GET, URL to /status
2. Drag an exec node - Command: uptime
3. Drag a template node - Format the response
4. Drag an http response node - Send the response

Connect them: http in → exec → template → http response

Deploy and visit http://your-server:1880/status

Essential Nodes

Built-in

Node	Purpose
inject	Trigger flows manually or on schedule
debug	View message data
function	JavaScript code
change	Modify message properties
switch	Conditional routing
http request	Make HTTP calls
exec	Run shell commands

Community Must-Haves

Install via Menu → Manage Palette:

• node-red-contrib-home-assistant - Home Assistant integration
• node-red-node-discord - Discord messaging
• node-red-contrib-influxdb - Metrics storage
• node-red-contrib-telegrambot - Telegram notifications
• node-red-dashboard - Create web dashboards

Practical Examples

Example 1: Discord Notifications for Container Health

[
  {
    "id": "exec-docker",
    "type": "exec",
    "command": "docker ps --filter health=unhealthy --format '{{.Names}}'",
    "addpay": false
  },
  {
    "id": "check-output",
    "type": "switch",
    "property": "payload",
    "rules": [
      { "t": "nempty" }
    ]
  },
  {
    "id": "discord-notify",
    "type": "discord-send",
    "channel": "YOUR_CHANNEL_ID"
  }
]

Schedule with inject node → Every 5 minutes.

Example 2: Daily Backup Reminder

// Function node - Check if backup ran today
const fs = global.get('fs');
const lastBackup = fs.statSync('/backups/latest').mtime;
const today = new Date();
const hoursSince = (today - lastBackup) / 1000 / 60 / 60;

if (hoursSince > 24) {
    msg.payload = `⚠️ Backup is ${Math.round(hoursSince)} hours old!`;
    return msg;
}
return null;

Example 3: API Data Transformation

Pull data from one API, transform, send to another:

[inject (cron)] → [http request (source)] → [function (transform)] → [http request (destination)]

Dashboard Creation

Install node-red-dashboard for instant web UIs:

# Within Node-RED
Menu → Manage Palette → Install → node-red-dashboard

Add dashboard nodes:

• ui_gauge - Display metrics
• ui_chart - Line/bar charts
• ui_button - Trigger actions
• ui_text - Display text
• ui_switch - Toggle controls

Access dashboard at http://your-server:1880/ui

Environment Variables

Secure credentials with environment variables:

docker-compose.yml

environment:
  - DISCORD_WEBHOOK=https://discord.com/api/webhooks/...
  - API_KEY=your-secret-key

Access in function nodes:

const webhook = env.get("DISCORD_WEBHOOK");

Flow Import/Export

Export

1. Select nodes
2. Ctrl+E (or Menu → Export)
3. Copy JSON or download file

Import

1. Ctrl+I (or Menu → Import)
2. Paste JSON or upload file
3. Click Import

Tips from Experience

1. Name your nodes - Future you will thank you
2. Use link nodes - Clean up complex flows
3. Comment everything - Add comment nodes explaining logic
4. Separate concerns - One flow per function
5. Backup flows - Export regularly to Git
6. Use context - Store data between messages

Security

⚠️ Node-RED has no authentication by default!

Add to settings.js:

adminAuth: {
    type: "credentials",
    users: [{
        username: "admin",
        password: "$2b$08$...", // bcrypt hash
        permissions: "*"
    }]
}

Generate hash:

node -e "console.log(require('bcryptjs').hashSync('your-password', 8));"

Learn More

• Node-RED Introduction
• Example Flows

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What automations have you built with Node-RED? Share on Discord!