Writing a byte to test10.socket is actually the root cause of issue #19154:
depending on the timing, it's possible that PID1 closes the socket before socat
(or nc, it doesn't matter which tool is actually used) tries to write that one
byte to the socket. In this case writing to the socket returns EPIPE, which
causes socat to exit(1) and subsequently make the test fail.
Since we're only interested in connecting to the socket and triggering the rate
limit of the socket, this patch removes the parts that write the single byte to
the socket, which should remove the race for good.
Since it shouldn't matter whether the test uses socat or nc, let's switch back
to nc and hence remove the sole user of socat. The exit status of nc is however
ignored because some versions might choke when the socket is closed
unexpectedly.
Alternative to https://github.com/systemd/systemd/pull/20531.
Whenever a service triggered by another unit fails condition checks,
stop the triggering unit to prevent systemd busy looping trying to
start the triggered unit.
Those are all consumed by our parser, so they all support comments.
I was considering whether they should have a license header at all,
but in the end I decided to add it because those files are often created
by copying parts of real unit files. And if the real ones have a license,
then those might as well. It's easier to add it than to make an exception.
Depending on the timing, socat will either get ECONNREFUSED oder EPIPE
from systemd. The latter will cause it to exit(1) and subsequently the
test to fail.
We are not actually interested in the return code of socat though. The
test is supposed to check, whether rate limiting of a socket unit works
properly.
So ignore any failures from the socat invocation and instead check, if
test10.socket is in state "failed" with result "trigger-limit-hit" after
it has been triggered.
TriggerLimitIntervalSec= by default is set to 2s. A "sleep 10" should
give systemd enough time even on slower machines, to reach the trigger
limit.
For better readability, break the test into separate ExecStart lines.
Fixes#19154.
