well, systemd's got them beat there!
… and the warrant canary we publish every Monday morning.
Ubuntu boxes: usually ok as long as you stay away from anything python related in the core system.
Doubtful the motivation was /etc/rc being too slow
daemontools, runit, s6 solve that problem
IIRC before PulseAudio we had to mess around with ALSA directly (memory hazy, it was a while ago). It could be a bit of a pain.
ALSA was kind of OK after mixing was enabled by default and if you didn't need to switch outputs of a running application between anything but internal speakers and headphones (which worked basically in hardware). With any additional devices that you could add and remove, ALSA became a more serious limitation, depending. You could usually choose your audio devices (including microphones) at least at the beginning of a video conference / playing a movie etc, but it was janky (unreliable, list of 20 devices for one multi-channel sound card) and needed explicit support from all applications. Not sure if it ever worked with Bluetooth.
It does, with the help of BlueALSA[0].
I get ALSA followed the Unix philosophy of doing one thing but I want my audio mixer to play multiple sounds at once.
I didn't actually know anything about Linux at the time and started with Gentoo because I saw a meme saying "install Gentoo" and people told me not to start with that distro. So it's possible I messed up the default config by accident.
Either way PulseAudio worked after I emerged it.
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.
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, it's really dumb, and effective. 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.
traditional inittab is older than that and there's not any reason to use it when you could be using runit, really.
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
"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.
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
You could also try targeting NetworkManager or networkd's "wait-online" services. Or if that doesn't work, something is telling systemd that you have an IP when you don't. NetworkManager has "ipv4.may-fail" and "ipv6.may-fail" that might be errenously true.
> at that point I might as well go back to init=/etc/rc
The difference is that systemd is much better at ensuring correctness. If you write the invoked shell command properly, it'll communicate failure or success correct and systemd will then communicate that state to the unit. It's still a lot more robust than before.
the problem is systemd
> The difference is that systemd is much better at ensuring correctness.
yeah, whatever mate
There is so much granularity and flexibility in what you can do it seems rather unlikely you cannot make it happen correctly. And if it is truly a bug... open an issue? They're rather responsive to it. And it isn't like the legacy init systems were bug free from inception (well, lord knows they were still chock full of bugs even when they were replaced).
Edit: sitting here with a grin .. HN downvoting the advice of checking logs, debugging and opening an issue. I wish the companies y'all work at good luck.. they'll need it.
I'm a pragmatist: I just want it to work
my solution to MULTIPLE different services binding to IP addresses is to turn on non-local ip binding
> There is so much granularity and flexibility in what you can do it seems rather unlikely you cannot make it happen correctly.
I've written an init before (in C), I know how the netlink interface to set an IP address and add routing table entries works
I understand the difference between monotonic and wall clocks
I know what's going on at every, single, level
and I can't stand how unreliable systemd makes nearly every single one of my, bluntly, completely vanilla systems
> And if it is truly a bug... open an issue?
did you read the link I pasted earlier?
I'm not wasting my time with that level of idiocy (from LP himself)
So basically it just doesn't work sometimes for no particular reason.
> The difference is that systemd is much better at ensuring correctness
Uh, well, you just said that it isn't, because some targets like network-online.target don't work from user unit files.
I'm not a systemd hater or anything, but I continue to read stuff from Poettering which to me is deeply disturbing given the programs he works on.
Saying it's not a bug that service is launched despite a stated required prerequisite dependency failed... WTF?
Sure, I agree with him that most computers should probably boot despite NTP being unable to sync. But proposing that the solution to that is breaking Requires is just wild to me.
The question in that issue is around the semantics of time-sync.target. Targets are synchronization points for the system and don't (afaik) generally make promises about the units that are ordered before them (in this case chrony-wait.service.
Does that answer your specific objection of "proposing that the solution to that is breaking Requires is just wild to me"? Basically, what is proposed in that issue is not breaking Requires=. The proposition is that the user add their own, specific Requires= as a drop-in configuration since that's not a generally-applicable default.
Targets[1]: Target units do not offer any additional functionality on top of the generic functionality provided by units. They merely group units, allowing a single target name to be used in Wants= and Requires= settings to establish a dependency on a set of units defined by the target, and in Before= and After= settings to establish ordering.
boot-complete.target[2]: Order units that shall only run when the boot process is considered successful after the target unit and pull in the target from it, also with Requires=.
Note use of "only run" with a reference to Requires=.
time-sync.target[3]: This target provides stricter clock accuracy guarantees than time-set.target (see above), but likely requires network communication and thus introduces unpredictable delays. Services that require clock accuracy and where network communication delays are acceptable should use this target.
Especially note the last sentence there.
The documentation clearly indicates that targets can fail, and that services that needs the target to be successful, should use Requires= to specify that.
If the above is not true, the Requires= and Targets documentation should be rewritten to explicitly say that targets might fulfill Requires= regardless of state. Also, the documentation for time-sync.target should explicitly remove the last sentence and instead state there is no functional difference between Requires=time-sync.target and Wants=time-sync.target, it is best-effort only.
[1]: https://www.freedesktop.org/software/systemd/man/latest/syst...
[2]: https://www.freedesktop.org/software/systemd/man/latest/syst...
[3]: https://www.freedesktop.org/software/systemd/man/latest/syst...
If he really don't want targets to deliver failed/success guarantees, then they've massively miscommunicated in their documentation. That in my book is a huge deal.
In either case the issue should in no circumstance be casually dismissed as not-a-bug without further action.
I'm sure the project would accept a documentation patch to amend this discrepancy. At the end of the day (despite what some people on the internet might like to allege), systemd is a free software project that, despite having (more or less) a BIFL, is ultimately a relatively bazaar-like project.
Though since these targets and unit properties are very core to systemd-the-service manager, I do think that this is a bigger documentation oversight than most.
To me this is a huge red flag for a senior contributer to a core systems component, signalling some fundamental lack of understanding or imagination.
I very much disagree with not fixing time-sync.target, but if he had instead written a well-reasoned explanation for why time-sync.target should not propagate failed states and flagging it as a documentation bug, then that's something I'd respect and would be fine with. Or, even better IMHO, he'd fix time-sync.target and state that users who wants to boot regardless should use Wants instead.
It is possible for a specification to be so abstract that it's useless.
I am not seeing these kind of systemd issues with Fedora / RHEL.
It just works
pulseaudio I had to fight every single day, with my "exotic" setup of one set of speakers and a headset
with pipewire, I've never had to even touch it
systemd: yesterday I had a network service on one machine not start up because the IP it was trying to bind to wasn't available yet
the dependencies for the .service file didn't/can't express the networking semantics correctly
this isn't some hacked up .service file I made, it's that from an extremely popular package from a very popular distro
(yeah I know, use a socket activated service......... more tight coupling to the garbage software)
the day before that I had a service fail to start because the wall clock was shifted by systemd-timesyncd during startup, and then the startup timeout fired because the clock advanced more than the timeout
then the week before that I had a load of stuff start before the time was synced, because chrony has some weird interactions with time-sync.target
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
for what? to save maybe a second of boot time
if the distro maintainers don't understand the systemd dependency model after a decade then it's unfit for purpose