Add a config reload command to create an initial config for L2 mode.

Step 1 in L2 config wiki actually serve the purpose of remove existing
minigraph config except for those that are absolutely necessary. We
should not skip that.

Author: hdwhdw

tests/l2/test_l2_configure.py

@@ -20,6 +20,15 @@
 ]
 
 
+def test_blah(duthosts, rand_one_dut_hostname, tbinfo):
+    duthost = duthosts[rand_one_dut_hostname]
+    logger.info("start printing fact")
+    logger.info(duthost.facts)
+    ext_minig_facts = duthost.get_extended_minigraph_facts(tbinfo)
+    logger.info("start printing minigraph fact")
+    logger.info(ext_minig_facts)
+
+
 def test_l2_config_and_upgrade(request, duthosts, rand_one_dut_hostname, localhost):
     """
     @summary: A testcase that verifies DB migrator does not add bad data.
@@ -71,7 +80,7 @@ def test_l2_config_and_upgrade(request, duthosts, rand_one_dut_hostname, localho
 
     # Step 4: Verifies no config fro minigraph is written into ConfigDB.
     try:
-        for table in ["TELEMETRY", "RESTAPI", "DEVICE_METADATA"]:
+        for table in ["TELEMETRY", "RESTAPI"]:
             count = int(duthost.shell('sonic-db-cli CONFIG_DB KEYS "{}|* | wc -l'.format(table))['stdout'])
             pytest_assert(count == 0, "{} table is not empty!".format(table))
     except Exception: