sdnotify tests: try real hard to kill socat processes

podman gating tests are hanging in the new Fedora CI setup;
long and tedious investigation suggests that 'socat' processes
are being left unkilled, which then causes BATS to hang when
it (presumably) runs a final 'wait' in its end cleanup.

The two principal changes are to exec socat in a subshell
with fd3 closed, and to pkill its child processes before
killing the process itself. I don't know if both are needed.
The pkill definitely is; the exec may just be superstition.
Since I've wasted more than a day of PTO time on this, I'm
okay with a little superstition. What I do know is that with
these two changes, my reproducer fails to reproduce in over
one hour of trying (normally it fails within 5 minutes).

AND, update: only rawhide (f35) leaves stray socat processes
behind. f33 and ubuntu do not, so 'pkill -P' fails.

I really have no idea what's going on.

Signed-off-by: Ed Santiago <santiago@redhat.com>
This commit is contained in:
Ed Santiago
2021-03-11 13:12:11 -07:00
parent 8d33bfabaa
commit 660a72993c

View File

@ -42,14 +42,22 @@ function _start_socat() {
_SOCAT_LOG="$PODMAN_TMPDIR/socat.log" _SOCAT_LOG="$PODMAN_TMPDIR/socat.log"
rm -f $_SOCAT_LOG rm -f $_SOCAT_LOG
socat unix-recvfrom:"$NOTIFY_SOCKET",fork \ # Execute in subshell so we can close fd3 (which BATS uses).
system:"(cat;echo) >> $_SOCAT_LOG" & # This is a superstitious ritual to try to avoid leaving processes behind,
# and thus prevent CI hangs.
(exec socat unix-recvfrom:"$NOTIFY_SOCKET",fork \
system:"(cat;echo) >> $_SOCAT_LOG" 3>&-) &
_SOCAT_PID=$! _SOCAT_PID=$!
} }
# Stop the socat background process and clean up logs # Stop the socat background process and clean up logs
function _stop_socat() { function _stop_socat() {
if [[ -n "$_SOCAT_PID" ]]; then if [[ -n "$_SOCAT_PID" ]]; then
# Kill all child processes, then the process itself.
# This is a superstitious incantation to avoid leaving processes behind.
# The '|| true' is because only f35 leaves behind socat processes;
# f33 (and perhaps others?) behave nicely. ARGH!
pkill -P $_SOCAT_PID || true
kill $_SOCAT_PID kill $_SOCAT_PID
fi fi
_SOCAT_PID= _SOCAT_PID=
@ -57,6 +65,7 @@ function _stop_socat() {
if [[ -n "$_SOCAT_LOG" ]]; then if [[ -n "$_SOCAT_LOG" ]]; then
rm -f $_SOCAT_LOG rm -f $_SOCAT_LOG
fi fi
_SOCAT_LOG=
} }
# Check that MAINPID=xxxxx points to a running conmon process # Check that MAINPID=xxxxx points to a running conmon process