From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 17 Feb 2025 10:34:27 +0000 (+0100)
Subject: test: fix racy machined test
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1237732;p=thirdparty%2Fsystemd.git

test: fix racy machined test

Previously, one of the io.systemd.Machine.Open() tests would invoke a
command line via machined, and then check if it ran properly. This was
implemented in a racy fashion: the client side would immediately close
the pty fd allocated for the operation, thus triggering an immediate
SIGHUP on the other side. Now, depending whether this client was quicker
in closing or the server was quicker in executing the command line this
was a race.

Fix this comprehensively: let's first wait for the varlink operation to
complete via the new "systemd-notify --fork" logic (because varlinkctl
sends out READY=1 once handing off to --exec). Secondly let's use
varlinkctl's --exec logic to invoke a process which keeps open the open
pty until we kill it (we just use sleep for that).

(Also add some more tests for the varlinkctl --exec stuff)
---

diff --git a/test/units/TEST-13-NSPAWN.machined.sh b/test/units/TEST-13-NSPAWN.machined.sh
index 5bc24236747..4875e48f809 100755
--- a/test/units/TEST-13-NSPAWN.machined.sh
+++ b/test/units/TEST-13-NSPAWN.machined.sh
@@ -388,9 +388,18 @@ varlinkctl call /run/systemd/machine/io.systemd.Machine io.systemd.Machine.Open
 varlinkctl call /run/systemd/machine/io.systemd.Machine io.systemd.Machine.Open '{"name": ".host", "mode": "shell"}'
 
 rm -f /tmp/none-existent-file
-varlinkctl call /run/systemd/machine/io.systemd.Machine io.systemd.Machine.Open '{"name": ".host", "mode": "shell", "user": "root", "path": "/bin/sh", "args": ["/bin/sh", "-c", "echo $FOO > /tmp/none-existent-file"], "environment": ["FOO=BAR"]}'
+
+# We need to make sure the acquired pty fd stays open if we invoke a command
+# server side, to not generate early SIGHUP. Hence, let's just invoke "sleep
+# infinity" client side, once we acquired the fd (passing it to it), and kill
+# it once we verified everything worked.
+PID=$(systemd-notify --fork -- varlinkctl --exec call /run/systemd/machine/io.systemd.Machine io.systemd.Machine.Open '{"name": ".host", "mode": "shell", "user": "root", "path": "/bin/bash", "args": ["/bin/bash", "-c", "echo $FOO > /tmp/none-existent-file"], "environment": ["FOO=BAR"]}' -- sleep infinity)
 timeout 30 bash -c "until test -e /tmp/none-existent-file; do sleep .5; done"
 grep -q "BAR" /tmp/none-existent-file
+kill "$PID"
+
+# Test varlinkctl's --exec fd passing logic properly
+assert_eq "$(varlinkctl --exec call /run/systemd/machine/io.systemd.Machine io.systemd.Machine.Open '{"name": ".host", "mode": "shell", "user": "root", "path": "/bin/bash", "args": ["/bin/bash", "-c", "echo $((7 + 8))"]}' -- bash -c 'read -r -N 2 x <&3 ; echo "$x"')" 15
 
 # test io.systemd.Machine.MapFrom
 varlinkctl call /run/systemd/machine/io.systemd.Machine io.systemd.Machine.MapFrom '{"name": "long-running", "uid":0, "gid": 0}'
diff --git a/test/units/TEST-74-AUX-UTILS.varlinkctl.sh b/test/units/TEST-74-AUX-UTILS.varlinkctl.sh
index a0797469a46..921fadf998c 100755
--- a/test/units/TEST-74-AUX-UTILS.varlinkctl.sh
+++ b/test/units/TEST-74-AUX-UTILS.varlinkctl.sh
@@ -160,3 +160,9 @@ done
 varlinkctl info /run/systemd/io.systemd.Hostname
 varlinkctl introspect /run/systemd/io.systemd.Hostname io.systemd.Hostname
 varlinkctl call /run/systemd/io.systemd.Hostname io.systemd.Hostname.Describe '{}'
+
+# Validate that --exec results in the very same values
+varlinkctl call /run/systemd/io.systemd.Hostname io.systemd.Hostname.Describe '{}' | jq > /tmp/describe1.json
+varlinkctl --exec call /run/systemd/io.systemd.Hostname io.systemd.Hostname.Describe '{}' -- jq > /tmp/describe2.json
+cmp /tmp/describe1.json /tmp/describe2.json
+rm /tmp/describe1.json /tmp/describe2.json