[Mellanox] Don't start & stop pmon when config reload (sonic-net#671)

Author: stephenxs

config/main.py

@@ -48,6 +48,16 @@ def log_error(msg):
     syslog.syslog(syslog.LOG_ERR, msg)
     syslog.closelog()
 
+#
+# Load asic_type for further use
+#
+
+try:
+    version_info = sonic_device_util.get_sonic_version_info()
+    asic_type = version_info['asic_type']
+except KeyError, TypeError:
+    raise click.Abort()
+
 #
 # Helper functions
 #
@@ -314,13 +324,16 @@ def _abort_if_false(ctx, param, value):
         ctx.abort()
 
 def _stop_services():
+    # on Mellanox platform pmon is stopped by syncd
     services_to_stop = [
         'swss',
         'lldp',
         'pmon',
         'bgp',
         'hostcfgd',
     ]
+    if asic_type == 'mellanox' and 'pmon' in services_to_stop:
+        services_to_stop.remove('pmon')
 
     for service in services_to_stop:
         try:
@@ -358,6 +371,7 @@ def _reset_failed_services():
             raise
 
 def _restart_services():
+    # on Mellanox platform pmon is started by syncd
     services_to_restart = [
         'hostname-config',
         'interfaces-config',
@@ -369,6 +383,8 @@ def _restart_services():
         'lldp',
         'hostcfgd',
     ]
+    if asic_type == 'mellanox' and 'pmon' in services_to_restart:
+        services_to_restart.remove('pmon')
 
     for service in services_to_restart:
         try:
@@ -1350,8 +1366,7 @@ def asymmetric(ctx, interface_name, status):
 def platform():
     """Platform-related configuration tasks"""
 
-version_info = sonic_device_util.get_sonic_version_info()
-if (version_info and version_info.get('asic_type') == 'mellanox'):
+if asic_type == 'mellanox':
     platform.add_command(mlnx.mlnx)
 
 #