testsuite: test signal propagation

Problem: There is no test in the testsuite that verifies that the
broker propagates nonfatal signals to jobs.

Add a test as issues/t5105-signal-propagation.sh that ensures a
nested instance propagates SIGUSR1 down to a leaf child job.

Author: grondo

t/Makefile.am

@@ -344,6 +344,7 @@ dist_check_SCRIPTS = \
 	issues/t4711-job-list-purge-inactive.sh \
 	issues/t4771-flux-start-bash.sh \
 	issues/t4852-t_submit-legacy.sh \
+	issues/t5105-signal-propagation.sh \
 	python/__init__.py \
 	python/subflux.py \
 	python/tap \

t/issues/t5105-signal-propagation.sh

@@ -0,0 +1,36 @@
+#!/bin/sh
+# Run an 3 level nested instance, with a test job at the final level
+
+waitfile=$SHARNESS_TEST_SRCDIR/scripts/waitfile.lua
+
+cat <<EOF >test.py
+import signal
+import time
+import flux
+import os
+
+h = flux.Flux()
+level = h.attr_get("instance-level")
+jobid = os.getenv("FLUX_JOB_ID")
+signal.signal(
+    signal.SIGUSR1,
+    lambda x, y: print(f"job {jobid} in level {level} got SIGUSR1", flush=True),
+)
+open("ready", 'a').close()
+signal.pause()
+EOF
+
+id=$(flux submit --output=log flux start \
+     flux run flux start \
+     flux run flux python ./test.py)
+
+$waitfile -t 30 -v ready
+
+flux job kill -s SIGUSR1 $id
+
+$waitfile -t 30 -v -p "got SIGUSR1" log
+
+flux job status --json -v $id
+
+# vi: ts=4 sw=4 expandtab
+