Kubernetes support commands update (#1133)

1) Upgrade Feature commands in both config & show to adopt the kube updates
2) kube join/reset upgraded to call kube_label command to add/remove label, which would trigger join/reset
3) few minor updates in kube code.

New/update to commands.

`sudo config feature owner <kube/local>`
To update owner

`sudo config feature fallback <on/off>`
To enable/disable fallback

`show feature status`
Shows the status of the feature. Extended to include kube-support related fields

`show feature config`
New command to show the current config info

`show kube server`
Extended to show config & status of server

Author: renukamanavalan

config/feature.py

@@ -11,6 +11,38 @@ def feature():
     """Configure features"""
     pass
 
+def _update_field(db, name, fld, val):
+    tbl = db.cfgdb.get_table('FEATURE')
+    if name not in tbl:
+        click.echo("Unable to retrieve {} from FEATURE table".format(name))
+        sys.exit(1)
+    db.cfgdb.mod_entry('FEATURE', name, { fld: val })
+    
+
+#
+# 'owner' command ('config feature owner ...')
+#
+@feature.command('owner', short_help="set owner for a feature")
+@click.argument('name', metavar='<feature-name>', required=True)
+@click.argument('owner', metavar='<owner>', required=True, type=click.Choice(["local", "kube"]))
+@pass_db
+def feature_owner(db, name, owner):
+    """Set owner for the feature"""
+    _update_field(db, name, "set_owner", owner)
+
+
+#
+# 'fallback' command ('config feature fallback ...')
+#
+@feature.command('fallback', short_help="set fallback for a feature")
+@click.argument('name', metavar='<feature-name>', required=True)
+@click.argument('fallback', metavar='<fallback>', required=True, type=click.Choice(["on", "off"]))
+@pass_db
+def feature_fallback(db, name, fallback):
+    """Set fallback for the feature"""
+    _update_field(db, name, "no_fallback_to_local", "false" if fallback == "on" else "true")
+
+
 #
 # 'state' command ('config feature state ...')
 #