podman/test/system/130-kill.bats
Valentin Rothberg 10569c988f journald logger: fix race condition
Fix a race in journald driver.  Following the logs implies streaming
until the container is dead.  Streaming happened in one goroutine,
waiting for the container to exit/die and signaling that event happened
in another goroutine.

The nature of having two goroutines running simultaneously is pretty
much the core of the race condition.  When the streaming goroutines
received the signal that the container has exitted, the routine may not
have read and written all of the container's logs.

Fix this race by reading both, the logs and the events, of the container
and stop streaming when the died/exited event has been read.  The died
event is guaranteed to be after all logs in the journal which guarantees
not only consistencty but also a deterministic behavior.

Note that the journald log driver now requires the journald event
backend to be set.

Fixes: #10323
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
2021-05-26 14:51:58 +02:00

107 lines
4.1 KiB
Bash

#!/usr/bin/env bats -*- bats -*-
#
# tests for podman kill
#
load helpers
@test "podman kill - test signal handling in containers" {
# Start a container that will handle all signals by emitting 'got: N'
local -a signals=(1 2 3 4 5 6 8 10 12 13 14 15 16 20 21 22 23 24 25 26 64)
run_podman run -d $IMAGE sh -c \
"for i in ${signals[*]}; do trap \"echo got: \$i\" \$i; done;
echo READY;
while ! test -e /stop; do sleep 0.05; done;
echo DONE"
# Ignore output regarding pulling/processing container images
cid=$(echo "$output" | tail -1)
# Run 'logs -f' on that container, but run it in the background with
# redirection to a named pipe from which we (foreground job) read
# and confirm that signals are received. We can't use run_podman here.
local fifo=${PODMAN_TMPDIR}/podman-kill-fifo.$(random_string 10)
mkfifo $fifo
$PODMAN logs -f $cid >$fifo </dev/null &
podman_log_pid=$!
# Open the FIFO for reading, and keep it open. This prevents a race
# condition in which the container can exit (e.g. if for some reason
# it doesn't handle the signal) and we (this test) try to read from
# the FIFO. Since there wouldn't be an active writer, the open()
# would hang forever. With this exec we keep the FD open, allowing
# 'read -t' to time out and report a useful error.
exec 5<$fifo
# First container emits READY when ready; wait for it.
read -t 10 -u 5 ready
is "$ready" "READY" "first log message from container"
# Helper function: send the given signal, verify that it's received.
kill_and_check() {
local signal=$1
local signum=${2:-$1} # e.g. if signal=HUP, we expect to see '1'
run_podman kill -s $signal $cid
read -t 10 -u 5 actual || die "Timed out: no ACK for kill -s $signal"
is "$actual" "got: $signum" "Signal $signal handled by container"
}
# Send signals in random order; make sure each one is received
for s in $(fmt --width=2 <<< "${signals[*]}" | sort --random-sort);do
kill_and_check $s
done
# Variations: with leading dash; by name, with/without dash or SIG
kill_and_check -1 1
kill_and_check -INT 2
kill_and_check FPE 8
kill_and_check -SIGUSR1 10
kill_and_check SIGUSR2 12
# Done. Tell the container to stop, and wait for final DONE
run_podman exec $cid touch /stop
read -t 5 -u 5 done || die "Timed out waiting for DONE from container"
is "$done" "DONE" "final log message from container"
# Clean up
run_podman wait $cid
run_podman rm $cid
wait $podman_log_pid
}
@test "podman kill - rejects invalid args" {
# These errors are thrown by the imported docker/signal.ParseSignal()
local -a bad_signal_names=(0 SIGBADSIG SIG BADSIG %% ! "''" '""' " ")
for s in ${bad_signal_names[@]}; do
# 'nosuchcontainer' is fine: podman should bail before it gets there
run_podman 125 kill -s $s nosuchcontainer
is "$output" "Error: invalid signal: $s" "Error from kill -s $s"
run_podman 125 pod kill -s $s nosuchpod
is "$output" "Error: invalid signal: $s" "Error from pod kill -s $s"
done
# Special case: these too are thrown by docker/signal.ParseSignal(),
# but the dash sign is stripped by our wrapper in utils, so the
# error message doesn't include the dash.
local -a bad_dash_signals=(-0 -SIGBADSIG -SIG -BADSIG -)
for s in ${bad_dash_signals[@]}; do
run_podman 125 kill -s $s nosuchcontainer
is "$output" "Error: invalid signal: ${s##-}" "Error from kill -s $s"
done
# This error (signal out of range) is thrown by our wrapper
local -a bad_signal_nums=(65 -65 96 999 99999999)
for s in ${bad_signal_nums[@]}; do
run_podman 125 kill -s $s nosuchcontainer
is "$output" "Error: valid signals are 1 through 64" \
"Error from kill -s $s"
done
# 'podman create' uses the same parsing code
run_podman 125 create --stop-signal=99 $IMAGE
is "$output" "Error: valid signals are 1 through 64" "podman create"
}
# vim: filetype=sh