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May I pre-empt my question by stating that I am new to the RPi3 and node-red. I have been trying to create a new node for node red, on my Rpi3, and in my last attempt something has gone wrong. When node red powers up the flow is present and can be deployed, but this is then joined with an error drop-down stating "Flows stopped due to missing node types. Check logs for details."

My main question is...How do I undo or scratch what I have done to get back to a working system?

I've struggled to find useful documentation to solve the problem myself; I hope someone can help, please.

Q1, "How do you check the logs?" What are they, where are they, how do you access them and what will they tell you? Some detail on how to access them would be very useful as I can find no practical reference to "logs" how to turn them on, view them etc., on the node-red interface or website.

After reading the node-red website I picked up on the fact there is a node-red-admin facility. I installed this and eventually managed to get logged in; I can see from issuing a node-red-admin list command that there is an error with a node I have created. The list displays node-red-contrib-demo/sample H-invertor error.

I am assuming this is the source of the problem and I've tried to remove the offending node using the remove command.

Issuing a node-red-admin remove node-red-contrib-demo/sample returns a message saying I'm not logged in ??? How should I issue this command?

Q2 Will removing the erroneous node solve the problem?

Q2a if the answer to Q2 is "yes", how do you do it? A detailed description would be beneficial.

Q2b if the answer is "no" how do you effectively clear the 1883 webpage and invoke a clean node-red canvas?

As a general comment I was really impressed with node-red. The nodes worked well and really sped up deployment. Excitedly I realised the potential in creating new nodes, however poor practical documentation on the process of creating new nodes and how to recover when things go wrong has led me to reach out.

I hope someone can help, so myself and others can get back on track.

user2496949
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1 Answers1

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As you are using Node-RED on a Raspberry Pi, you should read the Pi-specific docs here: http://nodered.org/docs/hardware/raspberrypi - which includes how to access the log:

sudo journalctl -f -u nodered -o cat

Alternatively, you can use the command node-red-log which is a wrapper for the above (and I've raised an issue to get the docs updated to mention that).

Once you have access to the log you will be able to determine:

  1. what flow file your instance of node-red is using
  2. any errors associated with the node you are developing

To tidy up your current workspace you can either:

  1. search your workspace for any 'unknown' nodes and delete them. Once deleted, hit deploy and, assuming you've removed them all, your flows will be running again.

  2. alternatively, if you want to complete wipe your flows, delete the flow file mentioned in the node-red log and restart.

If you want help in the specifics of debugging your node implementation, you may want to head over to the Node-RED mailing list or slack channels - both linked from the bottom of https://nodered.org

knolleary
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