systemd service

[DrTron]

As someone asked about this a while ago, I wrote a quick systemd service file for genmon.
It probably doesn't happen often, but if for some reason genmon dies, systemd will restart it, which it won't do with the crontab entry.
Just FYI...you'd have to change the path to startgenmon.sh and the working directory, obviously.

[Unit]
Description=genmon
After=network.target

[Service]
Type=forking
ExecStart=/usr/local/genmon/startgenmon.sh start
ExecReload=/usr/local/genmon/startgenmon.sh restart
ExecStop=/usr/local/genmon/startgenmon.sh stop
WorkingDirectory=/usr/local/genmon
StandardOutput=inherit
StandardError=inherit
Restart=always

[Install]
WantedBy=multi-user.target

[jgyates]

that is great info.

Question: if the startgenmon.sh script loads genloader.py which then loads multiple python scripts (genmon.py, genserv.py plus any add ons enabled), will systemd detect and restart based on the multiple python scripts dying?

[DrTron]

In it's current form, no.
It will detect spawned children and monitor them as a whole:

     CGroup: /system.slice/genmon.service
             ├─718629 /usr/local/genmon/genenv/bin/python /usr/local/genmon/genmon.py -c /etc/genmon/
             ├─718642 /usr/local/genmon/genenv/bin/python /usr/local/genmon/genserv.py -c /etc/genmon/
             └─718643 /usr/local/genmon/genenv/bin/python /usr/local/genmon/addon/genmqtt.py -c /etc/genmon/

That means that when all children have died, then the process is restarted, but not when just one of them dies.

It should be possible, though: for simplicity I chose to have the service call startgenmon.sh, mainly because that script checks a few parameters first before starting, such as the python environment, managed packages and such.
If the systemd service would be the one starting all the children above, then I think, yes, that would be possible. Maybe it's enough to have systemd call genloader.py, I'd have to see if that works.
I'm not a professional coder, though.