Accessing environment details from a Node-red flow

General
1

The node-red usage message (on Linux) shows that you can specify various runtime settings (irrelevant options removed from example):

node-red --help
Node-RED v4.0.9
Usage: node-red [--settings settings.js] [--userDir DIR]
                [--port PORT] [flows.json]
  • How can a flow discover the current pathnames of the directory, settings & flows files and port?

I suspect this requires use of the admin API?

I have asked an AI to write me a function to do this but it's answers, of course, are [expletive deleted].

I'm interested particularly on NR running on Linux, but a cross-platform solution would be a bonus.

2

With the diagnostics endpoint. You can try with the Show System Info action.

3

Is there an example flow somewhere that shows how to do that?

I see this page https://nodered.org/docs/api/admin/methods/get/diagnostics/ which documents the response object but not how to get there.

4

Complete the Authorization then it should work

[{"id":"7aab978c3ba7bde7","type":"inject","z":"15cdbf1d258ebb57","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":140,"y":340,"wires":[["31434da3af04fa94"]]},{"id":"22b3a08164c63aba","type":"debug","z":"15cdbf1d258ebb57","name":"debug 2","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":480,"y":340,"wires":[]},{"id":"31434da3af04fa94","type":"http request","z":"15cdbf1d258ebb57","name":"","method":"GET","ret":"txt","paytoqs":"ignore","url":"http://localhost:1880/diagnostics","tls":"","persist":false,"proxy":"","insecureHTTPParser":false,"authType":"","senderr":false,"headers":[{"keyType":"other","keyValue":"Accept","valueType":"other","valueValue":"application/json"},{"keyType":"other","keyValue":"Authorization","valueType":"other","valueValue":"Bearer [token]"}],"x":310,"y":340,"wires":[["22b3a08164c63aba"]]}]

Full version:

[{"id":"7aab978c3ba7bde7","type":"inject","z":"15cdbf1d258ebb57","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{\"client_id\":\"node-red-admin\",\"grant_type\":\"password\",\"scope\":\"*\",\"username\":\"admin\",\"password\":\"password\"}","payloadType":"json","x":130,"y":420,"wires":[["23ad1faed6ab4680"]]},{"id":"22b3a08164c63aba","type":"debug","z":"15cdbf1d258ebb57","name":"debug 2","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":800,"y":420,"wires":[]},{"id":"31434da3af04fa94","type":"http request","z":"15cdbf1d258ebb57","name":"","method":"GET","ret":"txt","paytoqs":"ignore","url":"http://localhost:1880/diagnostics","tls":"","persist":false,"proxy":"","insecureHTTPParser":false,"authType":"","senderr":false,"headers":[{"keyType":"other","keyValue":"Accept","valueType":"other","valueValue":"application/json"},{"keyType":"other","keyValue":"Authorization","valueType":"msg","valueValue":"payload"}],"x":630,"y":420,"wires":[["22b3a08164c63aba"]]},{"id":"23ad1faed6ab4680","type":"http request","z":"15cdbf1d258ebb57","name":"","method":"POST","ret":"txt","paytoqs":"ignore","url":"http://localhost:1880/auth/token","tls":"","persist":false,"proxy":"","insecureHTTPParser":false,"authType":"","senderr":false,"headers":[],"x":290,"y":420,"wires":[["ff30f98494e9198a"]]},{"id":"ff30f98494e9198a","type":"function","z":"15cdbf1d258ebb57","name":"function 1","func":"msg.payload = \"Bearer \" + JSON.parse(msg.payload)[\"access_token\"];\nreturn msg;","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":460,"y":420,"wires":[["31434da3af04fa94"]]}]
5

OK thanks.
Now I can get the name (not the full pathname) of the flows file from /diagnostics

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But I can't find the settings file in any of the API methods?

To be clear, these are the values I'm trying to obtain:

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6

I conclude that it's not possible via the admin API so the fallback seems to be the exec node

journalctl --boot=0  --grep="Settings file" --lines=1 --output=cat | awk '{print $NF}'
and 
journalctl --boot=0  --grep="Flows file" --lines=1 --output=cat | awk '{print $NF}'

which gives /home/pi/.node-red/settings.js and /home/pi/.node-red/flows.json

Unfortunately while the above works if you start Node-red with node-red-start or the systemd script, it seems that the output from node-red --settings nonStandardSettings.js nonStandardFlows.json is not logged. Rather strange.

7

When you run node-red --settings ... that runs node-red in the command window. When you run it via the systemd script it uses the command line parameters specified in the script. The command
systemctl cat nodered
will show you the script. In particular, if you uncomment the line
#Environment="NODE_RED_OPTIONS=-v"
you can put the settings file option in there
`Environment="NODE_RED_OPTIONS='--settings /path/to/nonStandardSettings.js'"
then I think that will do it. I have not tested it however, so the syntax may not be completely correct.

If you are running it as a service then you can reduce the amount of output from journalctl by adding -u nodered so it only shows output from the nodered service.

8

Thanks Colin.

I did not know about systemctl cat nodered, did know about (but omitted) -u nodered

I was interested to discover within a flow what settings and flows file it is using, regardless of how it was started up.

Actually the journalctl approach even if it worked would probably fall down on a device with two Node-red instances running.

9

Also, on a pi, I think the journal is not file based so if node red has been running for a month then it will be long gone.

You could set something in your settings file that identifies which file it is, which you can interrogate at run time.