[test]: Mark VLAN related mirror test invalid in Debian Jessie (#608)

Signed-off-by: Shu0T1an ChenG <shuche@microsoft.com>

tests/test_mirror.py

@@ -1,6 +1,9 @@
 # This test suite covers the functionality of mirror feature in SwSS
 
+import platform
+import pytest
 import time
+from distutils.version import StrictVersion
 
 from swsscommon import swsscommon
 
@@ -97,6 +100,7 @@ def get_mirror_session_status(self, name):
                 assert False
         return status
 
+
     def test_MirrorAddRemove(self, dvs):
         """
         This test covers the basic mirror session creation and removal operations
@@ -223,6 +227,9 @@ def remove_fdb(self, vlan, mac):
         time.sleep(1)
 
 
+    # Ignore testcase in Debian Jessie
+    # TODO: Remove this skip if Jessie support is no longer needed
+    @pytest.mark.skipif(StrictVersion(platform.linux_distribution()[1]) <= StrictVersion('8.9'), reason="Debian 8.9 or before has no support")
     def test_MirrorToVlanAddRemove(self, dvs):
         """
         This test covers basic mirror session creation and removal operation
@@ -427,6 +434,9 @@ def test_MirrorToLagAddRemove(self, dvs):
         self.remove_mirror_session(session)
 
 
+    # Ignore testcase in Debian Jessie
+    # TODO: Remove this skip if Jessie support is no longer needed
+    @pytest.mark.skipif(StrictVersion(platform.linux_distribution()[1]) <= StrictVersion('8.9'), reason="Debian 8.9 or before has no support")
     def test_MirrorDestMoveVlan(self, dvs):
         """
         This test tests mirror session destination move from non-VLAN to VLAN
@@ -697,6 +707,7 @@ def remove_mirror_acl_dscp_rule(self, table, rule):
         tbl._del(table + "|" + rule)
         time.sleep(1)
 
+
     def test_AclBindMirror(self, dvs):
         """
         This test tests ACL associated with mirror session with DSCP value