Node-RED

What it's good for#

Node-RED is for the jobs that fall between apps. Turn the heating down when everyone's phone leaves the house. Check a web page every morning and tell you if a price drops. Take a message from one service, tidy it up, and pass it to another. Each box, called a node, does one small thing: listen for something, make a web request, wait, compare, send. A chain of them is a flow.

It suits people who like tinkering but don't want to write and look after a program for every little job. You can drop into a line of JavaScript when a box doesn't do quite what you want, but a lot gets done without any.

Signing in#

Open it with the Flow Editor button on its page. The login is admin, and the password is in the Login Details shown when the install finishes; press Welcome on the app's page to see it again.

A plain Node-RED has no login at all, and anyone who opens the editor can run any command on your server with it. So LibrePortal writes the login into Node-RED's settings before it ever starts, checks after the install that the editor refuses anyone without it, and won't let Node-RED start if the login is ever missing from its settings.

To change the password, use Reset Admin Password on the Tools tab. Leave the box empty to have a strong one made for you. It changes the password in Node-RED and in LibrePortal together, and everyone signed in to the editor is signed out.

Your first flow#

From there, swap the ends for something useful. Double-click any node to change its settings; the help panel on the right explains what each one does. Node-RED's own cookbook is full of small, complete examples.

Adding nodes and a dashboard#

Node-RED comes with the basics. Thousands more nodes, for smart-home kit, databases, chat services and the rest, can be added from Manage palette in the editor's main menu. It downloads them from the public Node-RED library, and they're kept with the rest of Node-RED's data, so they survive updates and come back with a restore.

One worth knowing about is Dashboard 2.0 (@flowfuse/node-red-dashboard). It adds nodes for buttons, gauges, charts and switches, and turns them into a web page you can open on your phone to see and control your flows.

Webhooks and HTTP endpoints#

An http in node makes your flow answer a web address, like http://192.168.1.50:<port>/doorbell. They're served on the same port as the editor, so they get the same protection: only your trusted places can reach them. The editor's login doesn't cover them, though, so anyone who can reach the port can call them.

If a service on the internet has to reach one, you'll need to make the port public, or give Node-RED a domain, where it answers at flows.<your domain>. Either way, the editor becomes reachable from the internet too, protected only by its password.

Works with#

The one pairing LibrePortal knows about is ntfy: a flow can send a notification to your phone. Use an http request node set to POST, with the address http://ntfy-service:80/ and your topic after it, and put the message in msg.payload. Headers such as Title and Priority go in msg.headers. It talks to ntfy over LibrePortal's own network, so it works even when ntfy is private. The Works with list on Node-RED's page turns to connected once a deployed flow uses ntfy this way.

Good to know#

• Passwords saved in your flows are encrypted with a key LibrePortal made at install. Never change it: Node-RED could no longer read the passwords and tokens already saved in your flows.
• Backups include all of Node-RED's data: flows, the encrypted credentials, settings and the extra nodes you've installed.
• Updates are automatic, but only ever rebuilds of the exact release LibrePortal pins (5.0.7); a newer Node-RED reaches new installs, not this one. Nodes you've added from the palette stay as they are, so update them from Manage palette now and then.
• One per server. LibrePortal's login check and the Tools tab find Node-RED by its container name, so it can't run as several copies.