Fix display disorder problem of show mirror_session (#2447)

* Fix display disorder problem of mirror_session

acl_loader/main.py

@@ -842,8 +842,10 @@ def show_session(self, session_name):
                                          val.get("monitor_port", ""), val.get("src_port", ""), val.get("direction", "").lower()])
 
         print("ERSPAN Sessions")
+        erspan_data = natsorted(erspan_data)
         print(tabulate.tabulate(erspan_data, headers=erspan_header, tablefmt="simple", missingval=""))
         print("\nSPAN Sessions")
+        span_data = natsorted(span_data)
         print(tabulate.tabulate(span_data, headers=span_header, tablefmt="simple", missingval=""))
 
     def show_policer(self, policer_name):

tests/show_mirror_test.py

@@ -0,0 +1,43 @@
+import os
+import sys
+from swsscommon.swsscommon import SonicV2Connector
+from click.testing import CliRunner
+from utilities_common.db import Db
+
+import acl_loader.main as acl_loader_show
+from acl_loader import *
+from acl_loader.main import *
+
+class TestShowMirror(object):
+    def test_mirror_show(self):
+        runner = CliRunner()
+        aclloader = AclLoader()
+        aclloader.configdb.set_entry("MIRROR_SESSION", "session1", {"direction": "BOTH", "dst_port": "Ethernet30", "src_port": "Ethernet40", "type": "SPAN"})
+        aclloader.configdb.set_entry("MIRROR_SESSION", "session2", {"direction": "BOTH", "dst_port": "Ethernet7", "src_port": "Ethernet8", "type": "SPAN"})
+        aclloader.configdb.set_entry("MIRROR_SESSION", "session11", {"direction": "RX", "dst_port": "Ethernet9", "src_port": "Ethernet10", "type": "SPAN"})
+        aclloader.configdb.set_entry("MIRROR_SESSION", "session15", {"direction": "TX", "dst_port": "Ethernet2", "src_port": "Ethernet3", "type": "SPAN"})
+        aclloader.read_sessions_info()
+        context = {
+            "acl_loader": aclloader
+        }
+        expected_output = """\
+ERSPAN Sessions
+Name              Status    SRC IP    DST IP    GRE    DSCP    TTL    Queue    Policer    Monitor Port    SRC Port               Direction
+----------------  --------  --------  --------  -----  ------  -----  -------  ---------  --------------  ---------------------  -----------
+test_session_db1  active                                                                                   Ethernet40,Ethernet48  rx
+
+SPAN Sessions
+Name       Status    DST Port    SRC Port    Direction    Queue    Policer
+---------  --------  ----------  ----------  -----------  -------  ---------
+session1   active     Ethernet30  Ethernet40  both
+session2   active     Ethernet7   Ethernet8   both
+session11  active     Ethernet9   Ethernet10  rx
+session15  active     Ethernet2   Ethernet3   tx
+"""
+        result = runner.invoke(acl_loader_show.cli.commands['show'].commands['session'], [], obj=context)
+        assert result.exit_code == 0
+        print (result.output)
+        #The state of mirror_session depends on the state_db table entry. This case does not care about the state and is uniformly set to active.
+        result_output = result.output.replace('error', 'active')
+        result_output = result_output.replace('inactive', 'active')
+        assert result_output == expected_output