Comment by rcxdude
2 days ago
I always dreaded trying to create a service with bash-based init scripts. Not only did it involve rolling a heck of a lot yourself (the thing you were running was generally expected to do the double-fork hack itself and otherwise do 'well behaved daemon' things), it varied significantly from distro to distro, and I was never confident I actually got it right (and indeed, I often saw cases where it had most definitely gone wrong). Whereas systemd has a pretty trivial interface for running most anything and having some confidence it'll actually work right (in part because it can actually enforce things, like actually killing every process that's part of a service instead of kind of hoping that killing whats in the PIDfile is sufficient).
> the thing you were running was generally expected to do the double-fork hack itself and otherwise do 'well behaved daemon' things
FreeBSD has a general utility that does this for you, daemon(8): https://man.freebsd.org/cgi/man.cgi?query=daemon&sektion=8
I also use it every time I need a service which should be restarted on crash. It's a very handy utility.
Is this really that hard to type?
https://github.com/openbsd/src/blob/master/etc/rc.d/watchdog...
> Is this really that hard to type?
Your link is irrelevant. It points to OpenBSD which uses rc, not sysv. The 3 lines of this rc startup script use a file of 400 lines of shell with commands that don't exist in SysVinit.
With sysv, the difficulty depended on the local tools because the launching scripts could not be shared across Linux distributions. Debian used the compiled helper `start-stop-daemon` while Redhat did not.
With sysv, some sysadmin tasks require external tools. Try to write a launching script with a smart autorestart in case of crash. Make it work even when the daemon forks. Do not assume that the daemon writes its initial PID anywhere. IIRC, to get this feature, we had to drop sysv for runit, two decades ago. Now it's just 2 lines in a systemd unit.
Init and run control aren't the same thing. Which is part of what's nice about sysv (which, yes, OpenBSD's init is based on). OpenBSD's run control system is particularly nice, and it's the sort of thing you can use with an init system that isn't constantly eating everything.
Probably not, but it looks a hell of a lot harder to understand than a unit file.
Huh? Not even remotely
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