Raspberry Pi setup

Atmosphere

systemctl start triggercmdagent

Hi, i'm curious - i use python scripts to trigger my gpio pins on my raspberry... it appears that these are "Foreground" tasks... how do i do this in the background (so that when the pi reboots - it loads automatically again)

Any tips?

Russ

@atmosphere, in your commands.json file, make the ground field background instead of foreground. That way it will run in the context of the background service.

 {
  "trigger": "GPIO 6 on",
  "command": "python /root/gpio6on.py",
  "ground": "background",
  "voice": "6 on"
 },

Run this to install the background service:

/usr/share/triggercmdagent/app/src/installdaemon.sh

gutopa

Hi Russ..

Could you give me some tips about how to remove it from raspbian?

Thank you

Russ

@gutopa, you could uninstall the Raspberry Pi agent using these commands:

systemctl stop triggercmdagent
/usr/share/triggercmdagent/app/src/removedaemon.sh
apt remove triggercmdagent

Then you should delete the computer from your account on the website.

Erin Leiker

hello! my end goal is to launch an html file on my raspberry pi 3b+ using IFTTT (i have a small display plugged into my pi on which i'm expecting to see the file). i'm fairly sure i've gotten everything set up correctly in that i can see evidence of the command having run in IFTTT, my TRIGGERcmd dashboard, and in the CLI when i run "systemctl status triggercmdagent".

i have almost no native idea what i am doing, but i'm a pretty good tinkerer and an excellent copy-and-paster so the command i cobbled together is:
{"trigger":"myTriggerName","command":"chromium-browser file:///home/pi/myFile.html","ground":"background","voice":"myTriggerName","allowParams":"false"}

when i try to trigger that command via IFTTT or my TRIGGERcmd Triggers list, nothing actually happens other than the three locations i mention above showing some acknowledgement that the command was run. but when i run "chromium-browser file:///home/pi/myFile.html" via the CLI, the file opens in chromium exactly as i expect, so this all leads me to believe i have formatted the command incorrectly somehow.

any help here would be much appreciated!

Russ

@erin-leiker, I think the problem is you're running the triggercmd agent as a background daemon, and your command is running with "ground": "background", so you can't see the result of your command.

So to make it work, you'll need to:

Run the agent in the foreground by running the "triggercmdagent" command in a terminal window in X Windows.
Trigger your command in the foreground with "ground": "foreground" in your commands.json file.

Erin Leiker

@russ thank you for the tips! i did some googling on x windows, and it sounds like it's a way to access or view the pi remotely. do i still need x windows if i have the pi booting to the desktop and i have a screen on it so i can access it directly?

i updated the trigger to "foreground" and tried running triggercmdagent from the cli, but still i just see the log of the command having been run instead of the results of the command (opening that html file).

Russ

@erin-leiker, that's interesting. You might need to specify the full path of chromium-browser, so your command would be something like:

/path/to/chromium-browser file:///home/pi/myFile.html

To find the path, type this:

which chromium-browser

If you're booting to the GUI, that's X Windows. I'll boot up one of my Pi's and see if I can reproduce the problem you're having.

EDIT: I tried it on my Pi. I found that it worked with or without the full path. I tried /usr/bin/chromium-browser and just chromium-browser and both worked for me, so I don't know what's wrong in your case.
Can you try a simpler command, like echo Testing >> /tmp/test.txt ?
When I did that, it created a /tmp/test.txt file when I remotely ran the command.

Erin Leiker

@russ whew, i think i figured it out! if i'm right, it all comes down to users.

the instructions for installing on a raspberry pi are based on running all the commands/installations as a root user. the "chromuim-browser" command does not work when executed as the root user, only the default "pi" user. so i switched the command from "chromium-browser" to "xdg-open", which does essentially the same thing for my purposes, and it worked! well, almost.

i'm trying to launch an html file, and the mime type is "text/html" which opens with chromium by default for the pi user (yay!), but with the geany text editor for root (boo). i solved this by tweaking the command to run under the pi user, and it works as expected!

{"trigger":"myTriggerName","command":"su - pi -c 'xdg-open /home/pi/myFile.html'","ground":"foreground","voice":"myTriggerName","allowParams":"false"}

the only downside is that there is a noticeable delay in triggering this command. and i also have to open a terminal window, switch to the root user, and then run "triggercmdagent" before i can successfully trigger it. with this info, do you happen to know if/how i can:

auto run triggercmdagent on boot? the install instructions seem to state that it will launch in the background on boot, so i changed the command to "background" but no dice. still have to run triggercmdagent from terminal as root.
run/install triggercmdagent under the pi user instead of root? i think that would help speed up the execution of the command significantly.

thank you so much!

Russ

@erin-leiker, please give this a try:

Run this as your pi user to allow root to send stuff to your pi user's Xwindows:

xhost si:localuser:root

Install the background service as root with:

/usr/share/triggercmdagent/app/src/installdaemon.sh

Make sure this variable is set when your command runs as root in the context of your triggercmdagent:

export DISPLAY=:0.0

Your agent will be running in background mode, so the commands need "ground": "background" to run that way.

I suggest testing with galculator. It's an xwindows calculator app.