Fix Django 2.0 deprecation warnings

awx/main/models/credential/__init__.py

@@ -249,6 +249,7 @@ class Credential(PasswordFieldsModel, CommonModelNameNotUnique, ResourceMixin):
         'CredentialType',
         related_name='credentials',
         null=False,
+        on_delete=models.CASCADE,
         help_text=_('Specify the type of credential you want to create. Refer '
                     'to the Ansible Tower documentation for details on each type.')
     )

awx/main/models/ha.py

@@ -172,7 +172,8 @@ class InstanceGroup(HasPolicyEditsMixin, BaseModel, RelatedJobsMixin):
         help_text=_('Instance Group to remotely control this group.'),
         editable=False,
         default=None,
-        null=True
+        null=True,
+        on_delete=models.CASCADE
     )
     policy_instance_percentage = models.IntegerField(
         default=0,
@@ -264,8 +265,8 @@ class JobOrigin(models.Model):
     This is fine, and code should be able to handle it. A job with no origin
     is always assumed to *not* have the current instance as its origin.
     """
-    unified_job = models.OneToOneField(UnifiedJob, related_name='job_origin')
-    instance = models.ForeignKey(Instance)
+    unified_job = models.OneToOneField(UnifiedJob, related_name='job_origin', on_delete=models.CASCADE)
+    instance = models.ForeignKey(Instance, on_delete=models.CASCADE)
     created = models.DateTimeField(auto_now_add=True)
     modified = models.DateTimeField(auto_now=True)
 

awx/main/models/organization.py

@@ -147,6 +147,7 @@ class Profile(CreatedModifiedModel):
         'auth.User',
         related_name='profile',
         editable=False,
+        on_delete=models.CASCADE
     )
     ldap_dn = models.CharField(
         max_length=1024,

awx/main/models/rbac.py

@@ -150,7 +150,7 @@ class Role(models.Model):
         related_name='descendents'
     ) # auto-generated by `rebuild_role_ancestor_list`
     members = models.ManyToManyField('auth.User', related_name='roles')
-    content_type = models.ForeignKey(ContentType, null=True, default=None)
+    content_type = models.ForeignKey(ContentType, null=True, default=None, on_delete=models.CASCADE)
     object_id = models.PositiveIntegerField(null=True, default=None)
     content_object = GenericForeignKey('content_type', 'object_id')