> it's literally a new random problem every other boot because of this non-deterministic startup, which was never a problem with traditional init or /etc/rc

This gave me a good chuckle. Systemd literally was created to solve the awful race conditions and non-determinism in other init systems. And it has done a tremendous job at it. Hence the litany of options to ensure correct order and execution: https://www.freedesktop.org/software/systemd/man/latest/syst...

And outside of esoteric setups I haven't ever encountered the problems you mentioned with service files.

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direwolf20 an hour ago | parent | next [-]

systemd was created to solve the problems of a directory full of shell scripts. A single shell script has completely different problems. And traditional init uses inittab, which is not /etc/init.d, and works more like runit.

runit's approach is to just keep trying to start the shell script every 2 seconds until it works. One of those worse–is–better ideas. You can check for arbitrary conditions and error–exit, and it will keep trying. If you need the time synced you can just make your script fail if the time is not synced.

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blibble 2 hours ago | parent | prev [-]

yeah, many options that are complicated beyond the understanding of the distro maintainers, and yet still don't allow expression of common semantics required to support network services reliably

like "at least one real IP address is available" or "time has been synced"

and it's not esoteric, even ListenAddress with sshd doesn't even work reliably

the ONLY piece of systemd I've not had problems with is systemd-boot, and then it turned out they didn't write that

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jorvi an hour ago | parent [-]

> like "at least one real IP address is available" or "time has been synced"

"network-online.target is a target that actively waits until the network is “up”, where the definition of “up” is defined by the network management software. Usually it indicates a configured, routable IP address of some kind. Its primary purpose is to actively delay activation of services until the network has been set up."

For time sync checks, I assume one of the targets available will effectively mean a time sync has happened. Or you can do something with ExecStartPre. You could run a shell command that checks for the most recent time sync or forces one.

	▲	blibble an hour ago \| parent \| next [-]
		it's the "usually" that's the problem this service (untouched by me) had: After=local-fs.target network-online.target remote-fs.target time-sync.target but it was still started without an IP address, and then failed to bind just like this sort of problem: https://github.com/systemd/systemd/issues/4880#issuecomment-... the entire thing is unreliable and doesn't act like you'd expect > Or you can do something with ExecStartPre. You could run a shell command that checks for the most recent time sync or forces one. at that point I might as well go back to init=/etc/rc
	▲	direwolf20 an hour ago \| parent \| prev [-]
		Is it possible for network-online to mean that, or does network-on actually mean that? It is possible for a specification to be so abstract that it's useless.