Automation - Node-Red

Proven on:

	11 (bullseye)
	4
	19.3 / 20.3
	20.04.3	issues
	5.11

Node-Red Web Site

As always...

Start with:

• sudo apt update
• sudo apt upgrade

Installing Node-Red

Start by installing nodejs and the javascript package manager (npm)

FFFfffuuuuuu...

nodejs & npm versions are problematic.

For some reason, the versions available in all of the repositories tend to be out of date AND all attempts to update them fail in weird & wonderful ways.

I have found a procedure that seems to work

Use npm to install Node-RED

• sudo npm install -g node-red

Latest WTF?

Run it...

• node-red

Adding Autostart capability using SystemD

Then download three required files to their correct locations

• sudo wget https://raw.githubusercontent.com/node-red/raspbian-deb-package/master/resources/nodered.service -O /lib/systemd/system/nodered.service
• sudo wget https://raw.githubusercontent.com/node-red/raspbian-deb-package/master/resources/node-red-start -O /usr/bin/node-red-start
• sudo wget https://raw.githubusercontent.com/node-red/raspbian-deb-package/master/resources/node-red-stop -O /usr/bin/node-red-stop

Note: These 3 files are kinda rpi specific...

To run as a user other than Pi, you need to edit the nodered.service file. To edit this use sudo to edit the file /lib/systemd/system/nodered.service and change the lines 11, 12 and 13.

• sudo vi /lib/systemd/system/nodered.service

Replace the user name "pi" with a user on your actual system...

Another Note: If you find that you've outgrown Node-Reds available environment space...

i.e.: it starts crashing with a message like: FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory in the logs...

You can try editing line 16 of /lib/systemd/system/nodered.service and change the number 256 to something larger. (within as-yet undetermined limits...)

make the two scripts executable

• sudo chmod +x /usr/bin/node-red-st*

reload the systemd daemon

• sudo systemctl daemon-reload

enable Node-RED to run automatically

• sudo systemctl enable nodered.service

Start Node-RED

• sudo systemctl start nodered.service

Securing Node-RED

• Username/password based authentication
  • The suggestedadminAuth section is already there... edit it
  • You can create multiple users by duplicating the user object inside users: []
• Command-line Administration(how to get node-red-admin)

Useful management stuff

Learn about the current service status

• sudo systemctl status nodered.service

(Re-)Start the Node-RED background service

• sudo systemctl restart nodered.service

Stop the Node-RED background service

• sudo systemctl stop nodered.service

Disable the Node-RED background service

• sudo systemctl disable nodered.service

Get the service log since the last boot

• sudo journalctl -f -u nodered.service -b -o cat

Also

Node-RED can then be started and stopped by using the commands:

• node-red-start

and

• node-red-stop

Updating

Apparently, just run the install again...

• sudo npm install -g node-red

(pretty simple...)

Debugging Node-Red issues

ECONNRESET caused by MQTT

Error: Client network socket disconnected before secure TLS connection was established
Error: read ECONNRESET
Error: read ECONNRESET
Error: Client network socket disconnected before secure TLS connection was established

Hhhmmm...

ECONNREFUSED caused by alexa-home-conf

[error] [alexa-home-conf:919d2660.bd9218] Error: connect ECONNREFUSED 34.240.81.189:8883

Strange response from the creator: https://github.com/hardillb/node-red-contrib-alexa-home-skill/issues/51

Doesn't actually explain what's going on, but it's allegedly harmless. My question is: Why in fuck does it want to connect to a non-functional "alternate endpoint"?

Graceful restarts (maybe)

This is likely not needed when running under systemd...

From the Node-Red website

You can start a script as a daemon. But first install forever

sudo npm install -g --unsafe-perm forever

Then issue command:

forever start /usr/local/lib/node_modules/node-red/red.js

Things to do with Node-RED once it's installed

WIP:  These pages will appear as I get things updated from what's on the older wiki...

• Node-RED with Google Home
• Node-RED with InfluxDB
• Node-RED with Grafana

Some useful Node-Red tips

• Enable / Disable a Flow
• Search: node red function multiple inputs
• Node-Red stores it's data in ~/.node-red
• Palette Export or Backup

Some interesting Node-Red Add-Ons

• Machine learning package for node-red
• node-red-contrib-boolean-logic
  • Create "Buffer" from "Invert"
• node-red-contrib-google-home-notify
• node-red-dashboard
• node-red-node-ping
  • There seem to be other versions... possibly better...
• node-red-contrib-plex

Moving Node-Red to a new server

When creating a NEW server

NOTE: If you are updating to a much newer version of Node-Red, this is not likely the best technique...

Pretty easy actually...

Build the server & install everything as normal.

Then stop the node-red service and replace ~/.npm & ~/node-red with copies from the old server.

When Renaming a server

No longer seems to be an issue with current version of Node-Red...

(i.e.: Moving or cloning a VM...)

Seems to lose the flows. :(

They're not actually lost. :)

The flow files are named with the server name.

You can select a flow file in ~/.node-red/settings.js

Uncomment the line that says: //flowfile: 'flows.json', and change flows.json to the name of your actual flow file. (in the same folder...)

Then restart node-red

sudo systemctl restart nodered.service

If you are using other services on the server (i.e.: MQTT), you may run into further weirdness like having to tell nodes where to find these services. More research still required on this...