Is there a right way to update NR from a flow? Calling the official Pi script as a use case? From an exec node? Stop and restart of NR would be required of course. Expect the exec node to queue the task... so the actual Pi script runs as a separate process, which ensures the live NR instance can…

Working on a prototype experiment... Flow invokes bash script (1) via by exec node, sleeps, or watches pid of NR? Flow executes NR stop... yes this kills NR gracefully, so orphans an current active (ui) dashboard session Script (1) spawns Script (2) after sleep, or when pid NR disappears(?) Script…

Have you tried systemctl restart nodered from an exec node? I am not sure what that will do when it is invoked from within the process being restarted. I will see what I can find out.

look a this : [image] [EDIT] Displays if a new Node-Red update is available online, and update it from the Dashboard Share Your Projects This flow will search every 7 days if there is a new online version of Node-Red on https://nodered.org/ . If that is the case, [EDIT] : I…

I see that does (on a linux system) does a systemctl restart. I wonder if that is actually safe though, it depends on how it works whether killing the process that is running systemctl can cause problems.

That is why I abstract the restart via a separate script, the first script spawns from exec node, but is not a child process, just invoked by said active process, and shuts down NR. Then calls the install script. Then a spawned second script starts NR post install. By doing this, I am isolating e…

@SuperNinja Yes, I have my own variant of a 'watch' for new version flow as well. But my variant does not as yet, try to update NR. Will be interesting to see how the update sequence is done. I believe process isolation is the safe way to do any NR initialed NR updating.

If systemctl restart initiates a separate process to do the work, or just sends a message to a long running process then that is simpler and guaranteed to work.

You could use a separate node.js or python script that you run as a systemd service and that communicates with nodered over mqtt. This little service could than do the work of stopping/updating/starting and include error handling or even notify you if something goes wrong.

I have managed to glean some useful information on systemctl. This is from Colin Watson: "systemctl restart" is implemented as sending a single D-Bus method call (RestartUnit) to pid 1, so I believe this will indeed currently work since it's pid 1 that's doing the actual restart work and all tha…

Yeah, given systemctl has to be all powerful (compared to the services, most anyway) it controls, that model makes sense. There are other ways to control processes up and down the 'ring' scopes... if you know OS design, my reference to rings should be familiar. Recall on DG systems, there was a wa…

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Is there a right way to update NR from a flow?

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SuperNinja 22 November 2020 08:19 4

look a this :

Topic		Replies	Views
Run raspberry update script from nodered General	11	598	22 June 2021
Updating NR. What I thought should work doesn't General	11	521	4 April 2019
Locking up NR...and escape out from there General	18	2391	10 April 2019
Node-RED user api to restart the application (Node-RED) Core Development	23	675	25 March 2024
Upgrade node red within the flow editor General	7	690	11 June 2019

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Is there a right way to update NR from a flow?

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