[feature request] Allow execution of crons for exclusive "service" user (a user with no shell)

[ScrumpyJack]

My use case for cronmaster is as a scheduler with a nice UI. I don't use it as a UI for existing crontabs that users may have.

So I'd like to be able to create a cronmaster "system" user specfically without a shell (/bin/nologin or whatever), for the exclusive use of cronmaster, then schedule backups, monitoring and the like.

cron (i use cronie) has no problem with this, but cronmaster uses nsenter to change namespace and su to the executionUser user and fails if that user doesn't have a shell.

Maybe could you add the -s swich to su to fix this?

something like

) => nsenter -t 1 -m -u -i -n -p su -s ${executionShell} - ${executionUser} -c '${escapedCommand}';

https://github.com/fccview/cronmaster/blob/main/app/_consts/nsenter.ts#L4

I've not tested this.

[fccview]

Hey,

I'm gonna investigate this, I have no issues in this being an optional env variable, just needs a bunch of testing, so I may need you to assist me once I got something to show for ❤️

And yeah, I couldn't think of any cleaner way of running host machine jobs without using nsenter, this was always the biggest challenge not gonna lie