On Apr 27, 2015 16:39, "Lennart Poettering" <lenn...@poettering.net> wrote: > > On Sun, 26.04.15 14:32, Peter Paule (systemd-de...@fedux.org) wrote: > > > BTW: I did the `echo "asdf" > /dev/stderr`-thing just to test if > > `/dev/stderr` worked as expected. > > /dev/stderr does not work for socket fds, and that's a kernel > limitation, systemd can't do much bout it. > > > What I do not understand is: What changed in systemd that the > > service-unit-thing worked in some earlier versions? > > We changed nspawn so that it may be included in shell > pipelines. Effectively this meant passing through the original > stdin/stdout that nspawn got all the way down to PID 1 inside the > container. We do so now if we are invoked non-interactively, i.e. with > stdin/stdout not being a tty. > > Previously, we would never pass through fds, but always create a pty > inside the container and automatically forward all bytes of > stdin/stdout from outside the container to it and back. However, that > broke shell pipelines, since it ate up the independent EOF on stdin > and stdout: ptys cannot signal those individually (there's only a > hangup that terminates both directions at once), but that's a property > you inherently need for any kind of pipelines. > > I am pretty sure that the new behaviour is a ton more correct though: > with this you get the same behaviour if you start a process > non-intractively as a service or inside an nspawn container, the same > fds, and hence the same (broken) /dev/stderr semantics. > > > And what can I do to make it work again? There seems to be no other > > logging target _today_ both for nginx and apache which makes them > > compatible with journald. > > Do not use /dev/stderr. If you are in a shell script replace this: > > echo foobar > /dev/stderr > > with this > > echo foobar 1>&2 > > The latter will just duplicate stdin to stderr, the former will reopen > stdin as stderr. Which is a difference, though an non-obvious one, > that is further complicated that GNU bash (though not necessarily > other shells) actually automatically do the second command if you pass > it the first command. The first command does not work (in non-bash > shells..) if stdout is a socket, the second command does.
I'm guessing from the error message that it's not a shell script but nginx itself configured to use "/dev/stderr" as its log file, so there's no >& that could be used... > > Lennart > > -- > Lennart Poettering, Red Hat
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