support/run-test: add test for systemd using dbus-broker

Add four new tests for systemd (rw and ro in each case):
  - use dbus-broker instead of the original dbus
  - use the original dbus, with dbus-broker installed

The first two extend the existing IfUpDown test cases by just enabling
dbus-broker; the second ones extend this further, by explicitly enabling
the original dbus.

For one of the tests, we overload the test_run() function to test that
the dbus-broker daemon is indeed running as root. We need not replicate
that check in the other dbus-broker-only test, and it does not make
sense to test that in tests that have the original dbus enabled.

Presence of the original dbus and dbus-broker on the same system is
valid: the original dbus is used as the default system bus daemon. We do
not test switching between the two at runtime, though as this is really
too corner-case specific. We just test to ensure the original dbus
system bus daemon is not impacted by the presence of dbus-broker.

Note: the 'full' test-case enables all systemd options, and some of them
do pull the original dbus package, so we can't use that to test the
integration of dbus-broker; instead, we extend the ifupdown case, which
does not enable the original dbus.

The default external toolchain for cortex-A9 is the old ARM toolchain
which has kernel headers 4.10 Since dbus-broker needs toolchain headers
>= 4.17, it can't be selected with this toolchain. Switch the systemd
tests to the Bootlin toolchains instead. We switch all of them to make
things easier. Note that we will need to take care in the future that
the headers version used in the bootlin toolchain doesn't get bigger
than the kernel that is used. The kernel is currently 5.10, the headers
in the bleeding edge bootlin toolchain are 5.4.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Norbert Lange <nolange79@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

support/testing/tests/init/test_systemd.py

@@ -9,6 +9,7 @@ class InitSystemSystemdBase(InitSystemBase):
         BR2_cortex_a9=y
         BR2_ARM_ENABLE_VFP=y
         BR2_TOOLCHAIN_EXTERNAL=y
+        BR2_TOOLCHAIN_EXTERNAL_BOOTLIN=y
         BR2_INIT_SYSTEMD=y
         BR2_TARGET_GENERIC_GETTY_PORT="ttyAMA0"
         # BR2_TARGET_ROOTFS_TAR is not set
@@ -76,6 +77,29 @@ class TestInitSystemSystemdRoIfupdown(InitSystemSystemdBase):
         self.check_systemd("squashfs")
 
 
+class TestInitSystemSystemdRoIfupdownDbusbroker(TestInitSystemSystemdRoIfupdown):
+    config = TestInitSystemSystemdRoIfupdown.config + \
+        """
+        BR2_PACKAGE_DBUS_BROKER=y
+        """
+
+    def test_run(self):
+        # Parent class' test_run() method does exactly that, no more:
+        self.check_systemd("squashfs")
+
+        # Check that the dbus-broker daemon is running as non-root
+        cmd = "find /proc/$(pidof dbus-broker) -maxdepth 1 -name exe -user dbus"
+        out, _ = self.emulator.run(cmd)
+        self.assertEqual(len(out), 1)
+
+
+class TestInitSystemSystemdRoIfupdownDbusbrokerDbus(TestInitSystemSystemdRoIfupdownDbusbroker):
+    config = TestInitSystemSystemdRoIfupdownDbusbroker.config + \
+        """
+        BR2_PACKAGE_DBUS=y
+        """
+
+
 class TestInitSystemSystemdRwIfupdown(InitSystemSystemdBase):
     config = InitSystemSystemdBase.config + \
         """
@@ -88,6 +112,29 @@ class TestInitSystemSystemdRwIfupdown(InitSystemSystemdBase):
         self.check_systemd("ext2")
 
 
+class TestInitSystemSystemdRwIfupdownDbusbroker(TestInitSystemSystemdRwIfupdown):
+    config = TestInitSystemSystemdRwIfupdown.config + \
+        """
+        BR2_PACKAGE_DBUS_BROKER=y
+        """
+
+    def test_run(self):
+        # Parent class' test_run() method does exactly that, no more:
+        self.check_systemd("ext2")
+
+        # Check that the dbus-broker daemon is running as non-root
+        cmd = "find /proc/$(pidof dbus-broker) -maxdepth 1 -name exe -user dbus"
+        out, _ = self.emulator.run(cmd)
+        self.assertEqual(len(out), 1)
+
+
+class TestInitSystemSystemdRwIfupdownDbusbrokerDbus(TestInitSystemSystemdRwIfupdownDbusbroker):
+    config = TestInitSystemSystemdRwIfupdownDbusbroker.config + \
+        """
+        BR2_PACKAGE_DBUS=y
+        """
+
+
 class TestInitSystemSystemdRoFull(InitSystemSystemdBase):
     config = InitSystemSystemdBase.config + \
         """