Node asset amount (#2191)

* [Bugfix] 修复错误

* [Update] 修改树结构，统一api

apps/assets/serializers/asset.py

@@ -9,6 +9,7 @@ from .system_user import AssetSystemUserSerializer
 
 __all__ = [
     'AssetSerializer', 'AssetGrantedSerializer', 'MyAssetGrantedSerializer',
+    'AssetAsNodeSerializer',
 ]
 
 
@@ -22,6 +23,13 @@ class AssetSerializer(BulkSerializerMixin, serializers.ModelSerializer):
         fields = '__all__'
         validators = []
 
+    @classmethod
+    def setup_eager_loading(cls, queryset):
+        """ Perform necessary eager loading of data. """
+        queryset = queryset.prefetch_related('labels', 'nodes')\
+            .select_related('admin_user')
+        return queryset
+
     def get_field_names(self, declared_fields, info):
         fields = super().get_field_names(declared_fields, info)
         fields.extend([
@@ -30,6 +38,12 @@ class AssetSerializer(BulkSerializerMixin, serializers.ModelSerializer):
         return fields
 
 
+class AssetAsNodeSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Asset
+        fields = ['id', 'hostname', 'ip', 'port', 'platform', 'protocol']
+
+
 class AssetGrantedSerializer(serializers.ModelSerializer):
     """
     被授权资产的数据结构