smoketest: T3871: add running_in_smoketest_harness() base class method

Replace repeated `os.path.exists('/tmp/vyos.smoketests.hint')` checks
across multiple test files with a shared method on VyOSUnitTestSHIM.TestCase,
following the existing debug_on() convention.

Author: c-po

smoketest/scripts/cli/base_vyostest_shim.py

@@ -48,11 +48,16 @@ class TestCase(unittest.TestCase):
         # certain failure condition.
         debug = False
         mgmt_daemon_pid = 0
+        smoketest_hint_file = '/tmp/vyos.smoketests.hint'
 
         @staticmethod
         def debug_on():
             return os.path.exists('/tmp/vyos.smoketest.debug')
 
+        @classmethod
+        def running_in_smoketest_harness(cls):
+            return os.path.exists(cls.smoketest_hint_file)
+
         @classmethod
         def setUpClass(cls):
             cls._session = ConfigSession(os.getpid())

smoketest/scripts/cli/test_interfaces_bonding.py

@@ -366,7 +366,7 @@ def test_bonding_evpn_multihoming(self):
     def test_bonding_member_mtu(self):
         # This Smoketest only works on our CI platform where we force the NIC
         # to virtio and an MTU of only 1500 bytes max
-        if not os.path.exists('/tmp/vyos.smoketests.hint'):
+        if not self.running_in_smoketest_harness():
             self.skipTest('Not running under VyOS CI/CD QEMU environment!')
 
         for interface in self._interfaces:

smoketest/scripts/cli/test_protocols_static.py

@@ -596,7 +596,7 @@ def test_05_dhcp_default_route(self):
         # When running via vyos-build under the QEMU environment a local DHCP
         # server is available. This test verifies that the default route is set.
         # When not running under the VyOS QEMU environment, this test is skipped.
-        if not os.path.exists('/tmp/vyos.smoketests.hint'):
+        if not self.running_in_smoketest_harness():
             self.skipTest('Not running under VyOS CI/CD QEMU environment!')
 
         interface = 'eth0'
@@ -635,7 +635,7 @@ def test_06_dhcp_default_route_for_vrf(self):
         # When running via vyos-build under the QEMU environment a local DHCP
         # server is available. This test verifies that the default route is set.
         # When not running under the VyOS QEMU environment, this test is skipped.
-        if not os.path.exists('/tmp/vyos.smoketests.hint'):
+        if not self.running_in_smoketest_harness():
             self.skipTest('Not running under VyOS CI/CD QEMU environment!')
 
         interface = 'eth0'
@@ -683,7 +683,7 @@ def test_07_dhcp_interface_static_routes(self):
         # When running via vyos-build under the QEMU environment a local DHCP
         # server is available. This test verifies that static routes with
         # dhcp-interface are configured correctly.
-        if not os.path.exists('/tmp/vyos.smoketests.hint'):
+        if not self.running_in_smoketest_harness():
             self.skipTest('Not running under VyOS CI/CD QEMU environment!')
 
         dhcp_interface = 'eth0'

smoketest/scripts/cli/test_system_console.py

@@ -14,7 +14,6 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import os
 import unittest
 
 from base_vyostest_shim import VyOSUnitTestSHIM
@@ -60,7 +59,7 @@ def test_multiple_kernel_consoles(self):
             self.cli_commit()
 
     def test_fbcon_and_serial_con_switch(self):
-        if not os.path.exists('/tmp/vyos.smoketests.hint'):
+        if not self.running_in_smoketest_harness():
             self.skipTest('Not running under VyOS CI/CD QEMU environment!')
 
         grub_vars = get_grub_vars()