add get and patch operations

hub/broker/serializers.py

@@ -127,3 +127,20 @@ class ServiceOfferingSerializer(serializers.ModelSerializer):
 
 class CatalogSerializer(serializers.Serializer):
     services = ServiceOfferingSerializer(many=True)
+
+
+class ServiceInstanceUpdateSerializer(serializers.Serializer):
+    plan_id = serializers.CharField()
+
+    def validate_plan_id(self, value):
+        try:
+            plan = Plan.objects.get(pk=value)
+            # Get instance from context
+            instance = self.context.get("instance")
+            if str(plan.offering.id) != str(instance.offering.id):
+                raise serializers.ValidationError(
+                    "Plan does not belong to the current offering"
+                )
+            return plan
+        except Plan.DoesNotExist:
+            raise serializers.ValidationError("Invalid plan_id")