Restrict deletion of used cloud flavors and providers

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.'
+    )

src/ralph/virtual/api.py

@@ -1,7 +1,9 @@
 # -*- coding: utf-8 -*-
 from django.db import transaction
 from django.db.models import Prefetch
-from rest_framework import relations, serializers
+from django.utils.translation import ugettext_lazy as _
+from rest_framework import relations, serializers, status
+from rest_framework.response import Response
 
 from ralph.api import RalphAPISerializer, RalphAPIViewSet, router
 from ralph.api.serializers import RalphAPISaveSerializer
@@ -20,6 +22,7 @@
 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
@@ -180,11 +183,48 @@ class CloudFlavorViewSet(RalphAPIViewSet):
     prefetch_related = ['tags', 'virtualcomponent_set__model']
     filter_fields = ['flavor_id']
 
+    def destroy(self, request, *args, **kwargs):
+        instance = self.get_object()
+        force_delete = request.data.get('force', False)
+
+        if instance.cloudhost_set.count() != 0 and not force_delete:
+            raise Conflict(
+                _(
+                    "Cloud flavor is in use and hence is not delible. "
+                    "Use {\"force\": true} to force deletion."
+                )
+            )
+
+        self.perform_destroy(instance)
+        return Response(status=status.HTTP_204_NO_CONTENT)
+
 
 class CloudProviderViewSet(RalphAPIViewSet):
     queryset = CloudProvider.objects.all()
     serializer_class = CloudProviderSerializer
 
+    def _require_force_delete(self, cloud_provider):
+        return (
+            cloud_provider.cloudflavor_set.count() != 0 or
+            cloud_provider.cloudhost_set.count() != 0 or
+            cloud_provider.cloudproject_set.count() != 0
+        )
+
+    def destroy(self, request, *args, **kwargs):
+        instance = self.get_object()
+        force_delete = request.data.get('force', False)
+
+        if self._require_force_delete(instance) and not force_delete:
+            raise Conflict(
+                _(
+                    "Cloud provider is in use and hence is not delible. "
+                    "Use {\"force\": true} to force deletion."
+                )
+            )
+
+        self.perform_destroy(instance)
+        return Response(status=status.HTTP_204_NO_CONTENT)
+
 
 class CloudImageViewSet(RalphAPIViewSet):
     queryset = CloudImage.objects.all()

src/ralph/virtual/tests/test_api.py

@@ -298,6 +298,114 @@ 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.assertIn(
+            'Cloud flavor is in use and hence is not delible.',
+            resp.data['detail']
+        )
+        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_used_cloud_flavor_can_be_deleted_with_force(self):
+        # given
+        cloud_flavor = CloudFlavorFactory()
+        CloudHostFactory(cloudflavor=cloud_flavor)
+
+        # when
+        url = reverse('cloudflavor-detail', args=(cloud_flavor.pk,))
+        data = {'force': True}
+        resp = self.client.delete(url, data=data)
+
+        # then
+        self.assertEqual(resp.status_code, status.HTTP_204_NO_CONTENT)
+        self.assertRaises(
+            CloudFlavor.DoesNotExist,
+            cloud_flavor.refresh_from_db
+        )
+
+    @data(CloudFlavorFactory, CloudHostFactory, CloudProjectFactory)
+    def test_delete_cloud_provider_returns_409_if_has_child_objects(
+        self, child_type
+    ):
+        # given
+        cloud_provider = CloudProviderFactory(name="test-cloud-provider")
+        child_type(cloudprovider=cloud_provider)
+
+        # when
+        url = reverse('cloudprovider-detail', args=(cloud_provider.pk,))
+        resp = self.client.delete(url)
+
+        # then
+        self.assertEqual(resp.status_code, status.HTTP_409_CONFLICT)
+        self.assertIn(
+            'Cloud provider is in use and hence is not delible.',
+            resp.data['detail']
+        )
+        self.assertTrue(
+            CloudProvider.objects.filter(pk=cloud_provider.pk).exists()
+        )
+
+    def test_empty_cloud_provider_can_be_deleted(self):
+        # given
+        cloud_provider = CloudProviderFactory(name="test-cloud-provider")
+
+        # when
+        url = reverse('cloudprovider-detail', args=(cloud_provider.pk,))
+        resp = self.client.delete(url)
+
+        # then
+        self.assertEqual(resp.status_code, status.HTTP_204_NO_CONTENT)
+        self.assertRaises(
+            CloudProvider.DoesNotExist,
+            cloud_provider.refresh_from_db
+        )
+
+    @data(CloudFlavorFactory, CloudHostFactory, CloudProjectFactory)
+    def test_non_empty_cloud_provider_can_be_deleted_with_force(
+        self, child_type
+    ):
+        # given
+        cloud_provider = CloudProviderFactory(name="test-cloud-provider")
+        child_type(cloudprovider=cloud_provider)
+
+        # when
+        url = reverse('cloudprovider-detail', args=(cloud_provider.pk,))
+        data = {'force': True}
+        resp = self.client.delete(url, data=data)
+
+        # then
+        self.assertEqual(resp.status_code, status.HTTP_204_NO_CONTENT)
+        self.assertRaises(
+            CloudProvider.DoesNotExist,
+            cloud_provider.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 = {