From 0524d21c91d8213216104007d108ed2afee7f63e Mon Sep 17 00:00:00 2001
From: Roman Prykhodchenko <roman.prykhodchenko@allegro.pl>
Date: Mon, 27 Apr 2020 17:12:47 +0200
Subject: [PATCH] Disable deletion of used cloud flavors

---
 src/ralph/lib/api/exceptions.py     | 10 +++++++++
 src/ralph/virtual/api.py            | 10 +++++++++
 src/ralph/virtual/tests/test_api.py | 34 +++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+)
 create mode 100644 src/ralph/lib/api/exceptions.py

diff --git a/src/ralph/lib/api/exceptions.py b/src/ralph/lib/api/exceptions.py
new file mode 100644
index 0000000000..84ae4a76ca
--- /dev/null
+++ b/src/ralph/lib/api/exceptions.py
@@ -0,0 +1,10 @@
+from django.utils.translation import ugettext_lazy as _
+from rest_framework import status
+from rest_framework.exceptions import APIException
+
+
+class Conflict(APIException):
+    status_code = status.HTTP_409_CONFLICT
+    default_detail = _(
+        'State of the resource is in conflict with the request.'
+    )
diff --git a/src/ralph/virtual/api.py b/src/ralph/virtual/api.py
index ed683359d7..f3944e60da 100644
--- a/src/ralph/virtual/api.py
+++ b/src/ralph/virtual/api.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 from django.db import transaction
 from django.db.models import Prefetch
+from django.utils.translation import ugettext_lazy as _
 from rest_framework import relations, serializers
 
 from ralph.api import RalphAPISerializer, RalphAPIViewSet, router
@@ -20,6 +21,7 @@
 from ralph.configuration_management.api import SCMInfoSerializer
 from ralph.data_center.api.serializers import DataCenterAssetSimpleSerializer
 from ralph.data_center.models import DCHost
+from ralph.lib.api.exceptions import Conflict
 from ralph.security.api import SecurityScanSerializer
 from ralph.security.models import SecurityScan
 from ralph.virtual.admin import VirtualServerAdmin
@@ -180,6 +182,14 @@ class CloudFlavorViewSet(RalphAPIViewSet):
     prefetch_related = ['tags', 'virtualcomponent_set__model']
     filter_fields = ['flavor_id']
 
+    def perform_destroy(self, instance):
+        if instance.cloudhost_set.count() != 0:
+            raise Conflict(
+                _("Cloud flavor is in use and hence is not delible.")
+            )
+
+        return super().perform_destroy(instance)
+
 
 class CloudProviderViewSet(RalphAPIViewSet):
     queryset = CloudProvider.objects.all()
diff --git a/src/ralph/virtual/tests/test_api.py b/src/ralph/virtual/tests/test_api.py
index f1adc03200..dbd53d7220 100644
--- a/src/ralph/virtual/tests/test_api.py
+++ b/src/ralph/virtual/tests/test_api.py
@@ -298,6 +298,40 @@ def test_patch_cloudprovider(self):
         provider = CloudProvider.objects.get(name=args['name'])
         self.assertEqual(provider.name, args['name'])
 
+    def test_delete_cloud_flavor_returns_409_if_is_used_by_cloud_hosts(self):
+        # given
+        cloud_flavor = CloudFlavorFactory()
+        CloudHostFactory(cloudflavor=cloud_flavor)
+
+        # when
+        url = reverse('cloudflavor-detail', args=(cloud_flavor.pk,))
+        resp = self.client.delete(url)
+
+        # then
+        self.assertEqual(resp.status_code, status.HTTP_409_CONFLICT)
+        self.assertEqual(
+            resp.data['detail'],
+            'Cloud flavor is in use and hence is not delible.'
+        )
+        self.assertTrue(
+            CloudFlavor.objects.filter(pk=cloud_flavor.pk).exists()
+        )
+
+    def test_unused_cloud_flavor_can_be_deleted(self):
+        # given
+        cloud_flavor = CloudFlavorFactory()
+
+        # when
+        url = reverse('cloudflavor-detail', args=(cloud_flavor.pk,))
+        resp = self.client.delete(url)
+
+        # then
+        self.assertEqual(resp.status_code, status.HTTP_204_NO_CONTENT)
+        self.assertRaises(
+            CloudFlavor.DoesNotExist,
+            cloud_flavor.refresh_from_db
+        )
+
     def test_inheritance_of_service_env_on_change_in_a_cloud_project(self):
         url = reverse('cloudproject-detail', args=(self.cloud_project.id,))
         args = {