awx/awx/main/fields.py

264 lines
10 KiB
Python

# Copyright (c) 2015 Ansible, Inc.
# All Rights Reserved.
# Django
from django.db.models.signals import post_save
from django.db.models.signals import m2m_changed
from django.db import models
from django.db.models.fields.related import (
add_lazy_relation,
SingleRelatedObjectDescriptor,
ReverseSingleRelatedObjectDescriptor,
ManyRelatedObjectsDescriptor,
ReverseManyRelatedObjectsDescriptor,
)
from django.core.exceptions import FieldError
# AWX
from awx.main.models.rbac import Resource, RolePermission, Role
__all__ = ['AutoOneToOneField', 'ImplicitResourceField', 'ImplicitRoleField']
# Based on AutoOneToOneField from django-annoying:
# https://bitbucket.org/offline/django-annoying/src/a0de8b294db3/annoying/fields.py
class AutoSingleRelatedObjectDescriptor(SingleRelatedObjectDescriptor):
"""Descriptor for access to the object from its related class."""
def __get__(self, instance, instance_type=None):
try:
return super(AutoSingleRelatedObjectDescriptor,
self).__get__(instance, instance_type)
except self.related.related_model.DoesNotExist:
obj = self.related.related_model(**{self.related.field.name: instance})
if self.related.field.rel.parent_link:
raise NotImplementedError('not supported with polymorphic!')
for f in instance._meta.local_fields:
setattr(obj, f.name, getattr(instance, f.name))
obj.save()
return obj
class AutoOneToOneField(models.OneToOneField):
"""OneToOneField that creates related object if it doesn't exist."""
def contribute_to_related_class(self, cls, related):
setattr(cls, related.get_accessor_name(),
AutoSingleRelatedObjectDescriptor(related))
class ResourceFieldDescriptor(ReverseSingleRelatedObjectDescriptor):
"""Descriptor for access to the object from its related class."""
def __init__(self, *args, **kwargs):
super(ResourceFieldDescriptor, self).__init__(*args, **kwargs)
def __get__(self, instance, instance_type=None):
resource = super(ResourceFieldDescriptor, self).__get__(instance, instance_type)
if resource:
return resource
resource = Resource._default_manager.create(content_object=instance)
setattr(instance, self.field.name, resource)
instance.save(update_fields=[self.field.name,])
return resource
class ImplicitResourceField(models.ForeignKey):
"""Creates an associated resource object if one doesn't already exist"""
def __init__(self, *args, **kwargs):
kwargs.setdefault('to', 'Resource')
kwargs.setdefault('related_name', '+')
kwargs.setdefault('null', 'True')
super(ImplicitResourceField, self).__init__(*args, **kwargs)
def contribute_to_class(self, cls, name):
super(ImplicitResourceField, self).contribute_to_class(cls, name)
setattr(cls, self.name, ResourceFieldDescriptor(self))
post_save.connect(self._save, cls, True)
def _save(self, instance, *args, **kwargs):
# Ensure that our field gets initialized after our first save
getattr(instance, self.name)
class ImplicitRoleDescriptor(ReverseSingleRelatedObjectDescriptor):
"""Descriptor Implict Role Fields. Auto-creates the appropriate role entry on first access"""
def __init__(self, role_name, resource_field, permissions, parent_role, *args, **kwargs):
self.role_name = role_name
self.resource_field = resource_field
self.permissions = permissions
self.parent_role = parent_role
super(ImplicitRoleDescriptor, self).__init__(*args, **kwargs)
def __get__(self, instance, instance_type=None):
role = super(ImplicitRoleDescriptor, self).__get__(instance, instance_type)
if role:
return role
if not self.role_name:
raise FieldError('Implicit role missing `role_name`')
role = Role._default_manager.create(name=self.role_name, content_object=instance)
if self.parent_role:
def resolve_field(obj, field):
ret = []
field_components = field.split('.', 1)
if hasattr(obj, field_components[0]):
obj = getattr(obj, field_components[0])
else:
return []
if len(field_components) == 1:
if type(obj) is not ImplicitRoleDescriptor and type(obj) is not Role:
raise Exception('%s refers to a %s, not an ImplicitRoleField or Role' % (field, str(type(obj))))
ret.append(obj)
else:
if type(obj) is ManyRelatedObjectsDescriptor:
for o in obj.all():
ret += resolve_field(o, field_components[1])
else:
ret += resolve_field(obj, field_components[1])
return ret
# Add all non-null parent roles as parents
paths = self.parent_role if type(self.parent_role) is list else [self.parent_role]
for path in paths:
if path.startswith("singleton:"):
parents = [Role.singleton(path[10:])]
else:
parents = resolve_field(instance, path)
for parent in parents:
role.parents.add(parent)
setattr(instance, self.field.name, role)
instance.save(update_fields=[self.field.name,])
if self.resource_field and self.permissions:
permissions = RolePermission(
role=role,
resource=getattr(instance, self.resource_field)
)
if 'all' in self.permissions and self.permissions['all']:
del self.permissions['all']
self.permissions['create'] = True
self.permissions['read'] = True
self.permissions['write'] = True
self.permissions['update'] = True
self.permissions['delete'] = True
self.permissions['scm_update'] = True
self.permissions['use'] = True
self.permissions['execute'] = True
for k,v in self.permissions.items():
setattr(permissions, k, v)
permissions.save()
return role
class ImplicitRoleField(models.ForeignKey):
"""Implicitly creates a role entry for a resource"""
def __init__(self, role_name=None, resource_field=None, permissions=None, parent_role=None, *args, **kwargs):
self.role_name = role_name
self.resource_field = resource_field
self.permissions = permissions
self.parent_role = parent_role
kwargs.setdefault('to', 'Role')
kwargs.setdefault('related_name', '+')
kwargs.setdefault('null', 'True')
super(ImplicitRoleField, self).__init__(*args, **kwargs)
def contribute_to_class(self, cls, name):
super(ImplicitRoleField, self).contribute_to_class(cls, name)
setattr(cls,
self.name,
ImplicitRoleDescriptor(
self.role_name,
self.resource_field,
self.permissions,
self.parent_role,
self
)
)
post_save.connect(self._save, cls, True)
add_lazy_relation(cls, self, "self", self.bind_m2m_changed)
def bind_m2m_changed(self, _self, _role_class, cls):
if not self.parent_role:
return
field_names = self.parent_role
if type(field_names) is not list:
field_names = [field_names]
found_m2m_field = False
for field_name in field_names:
if field_name.startswith('singleton:'):
continue
first_field_name = field_name.split('.')[0]
field = getattr(cls, first_field_name)
if type(field) is ReverseManyRelatedObjectsDescriptor or \
type(field) is ManyRelatedObjectsDescriptor:
if found_m2m_field:
# This limitation is due to a lack of understanding on my part, the
# trouble being that I can't seem to get m2m_changed to call anything that
# encapsulates what field we're working with. So the workaround that I've
# settled on for the time being is to simply iterate over the fields in the
# m2m_update and look for the m2m map and update accordingly. This solution
# is lame, I'd love for someone to show me the way to get the necessary
# state down to the m2m_update callback. - anoek 2016-02-10
raise Exception('Multiple ManyToMany fields not allowed in parent_role list')
if len(field_name.split('.')) != 2:
raise Exception('Referencing deep roles through ManyToMany fields is unsupported.')
found_m2m_field = True
self.m2m_field_name = first_field_name
self.m2m_field_attr = field_name.split('.',1)[1]
if type(field) is ReverseManyRelatedObjectsDescriptor:
m2m_changed.connect(self.m2m_update, field.through)
else:
m2m_changed.connect(self.m2m_update_related, field.related.through)
def m2m_update_related(self, **kwargs):
kwargs['reverse'] = not kwargs['reverse']
self.m2m_update(**kwargs)
def m2m_update(self, sender, instance, action, reverse, model, pk_set, **kwargs):
if action == 'post_add' or action == 'pre_remove':
if reverse:
for pk in pk_set:
obj = model.objects.get(pk=pk)
if action == 'post_add':
getattr(instance, self.name).children.add(getattr(obj, self.m2m_field_attr))
if action == 'pre_remove':
getattr(instance, self.name).children.remove(getattr(obj, self.m2m_field_attr))
else:
for pk in pk_set:
obj = model.objects.get(pk=pk)
if action == 'post_add':
getattr(instance, self.name).parents.add(getattr(obj, self.m2m_field_attr))
if action == 'pre_remove':
getattr(instance, self.name).parents.remove(getattr(obj, self.m2m_field_attr))
def _save(self, instance, *args, **kwargs):
# Ensure that our field gets initialized after our first save
getattr(instance, self.name)