sysctl: add --strict option to fail if sysctl does not exists

systemd-sysctl currently fails silently under any of these conditions:
- Missing permission to write a sysctl.
- Invalid sysctl (path doesn't exists).
- Ignore failure flag ('-' in front of the sysctl name).

Because of this behaviour, configuration issues can go unnoticed as
there is no way to detect those unless going through the logs.

--strict option forces systemd-sysctl to fail if a sysctl is invalid or
if permission are insufficient. Errors on sysctl marked as "ignore
failure" will still be ignored.

4 files changed, 40 insertions, 0 deletions

diff --git a/test/TEST-76-SYSCTL/Makefile b/test/TEST-76-SYSCTL/Makefile
new file mode 100644
index 0000000000..9f65d4ca4f
--- /dev/null
+++ b/test/TEST-76-SYSCTL/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+all setup run clean clean-again:
+	@TEST_BASE_DIR=../ ./test.sh --$@
+
+.PHONY: all setup run clean clean-again
diff --git a/test/TEST-76-SYSCTL/test.sh b/test/TEST-76-SYSCTL/test.sh
new file mode 100755
index 0000000000..11a44afaf5
--- /dev/null
+++ b/test/TEST-76-SYSCTL/test.sh
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -e
+
+TEST_DESCRIPTION="Sysctl-related tests"
+
+# shellcheck source=test/test-functions
+. "${TEST_BASE_DIR:?}/test-functions"
+
+do_test "$@"
diff --git a/test/units/testsuite-76.service b/test/units/testsuite-76.service
new file mode 100644
index 0000000000..3c8a9e867f
--- /dev/null
+++ b/test/units/testsuite-76.service
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+[Unit]
+Description=TEST-76-SYSCTL
+
+[Service]
+ExecStartPre=rm -f /failed /testok
+ExecStart=/usr/lib/systemd/tests/testdata/units/%N.sh
+Type=oneshot
diff --git a/test/units/testsuite-76.sh b/test/units/testsuite-76.sh
new file mode 100755
index 0000000000..6ebdbc6a54
--- /dev/null
+++ b/test/units/testsuite-76.sh
@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eux
+set -o pipefail
+
+export SYSTEMD_LOG_LEVEL=debug
+
+echo "foo.bar=42" > /etc/sysctl.d/foo.conf
+[[ $(/usr/lib/systemd/systemd-sysctl /etc/sysctl.d/foo.conf)$? -eq 0 ]]
+[[ $(/usr/lib/systemd/systemd-sysctl --strict /etc/sysctl.d/foo.conf)$? -ne 0 ]]
+
+echo "-foo.foo=42" > /etc/sysctl.d/foo.conf
+[[ $(/usr/lib/systemd/systemd-sysctl /etc/sysctl.d/foo.conf)$? -eq 0 ]]
+[[ $(/usr/lib/systemd/systemd-sysctl --strict /etc/sysctl.d/foo.conf)$? -eq 0 ]]
+
+touch /testok