''' Provide a hook for supplying authorization mechanisms to a Bokeh server.
'''
#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import annotations
import logging # isort:skip
log = logging.getLogger(__name__)
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Standard library imports
import importlib.util
from os.path import isfile
from types import ModuleType
from typing import (
TYPE_CHECKING,
Awaitable,
Callable,
NewType,
)
# External imports
from tornado.httputil import HTTPServerRequest
from tornado.web import RequestHandler
# Bokeh imports
from ..util.serialization import make_globally_unique_id
if TYPE_CHECKING:
from ..core.types import PathLike
#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------
__all__ = (
'AuthModule',
'AuthProvider',
'NullAuth',
)
#-----------------------------------------------------------------------------
# General API
#-----------------------------------------------------------------------------
User = NewType("User", object)
[docs]
class AuthProvider:
''' Abstract base class for implementing authorization hooks.
Subclasses must supply one of: ``get_user`` or ``get_user_async``.
Subclasses must also supply one of ``login_url`` or ``get_login_url``.
Optionally, if ``login_url`` provides a relative URL, then ``login_handler``
may also be supplied.
The properties ``logout_url`` and ``get_logout_handler`` are analogous to
the corresponding login properties, and are optional.
'''
def __init__(self) -> None:
self._validate()
@property
def endpoints(self) -> list[tuple[str, type[RequestHandler]]]:
''' URL patterns for login/logout endpoints.
'''
endpoints: list[tuple[str, type[RequestHandler]]] = []
if self.login_handler:
assert self.login_url is not None
endpoints.append((self.login_url, self.login_handler))
if self.logout_handler:
assert self.logout_url is not None
endpoints.append((self.logout_url, self.logout_handler))
return endpoints
@property
def get_login_url(self) -> Callable[[HTTPServerRequest], str] | None:
''' A function that computes a URL to redirect unauthenticated users
to for login.
This property may return None, if a ``login_url`` is supplied
instead.
If a function is returned, it should accept a ``RequestHandler``
and return a login URL for unauthenticated users.
'''
pass
@property
def get_user(self) -> Callable[[HTTPServerRequest], User] | None:
''' A function to get the current authenticated user.
This property may return None, if a ``get_user_async`` function is
supplied instead.
If a function is returned, it should accept a ``RequestHandler``
and return the current authenticated user.
'''
pass
@property
def get_user_async(self) -> Callable[[HTTPServerRequest], Awaitable[User]] | None:
''' An async function to get the current authenticated user.
This property may return None, if a ``get_user`` function is supplied
instead.
If a function is returned, it should accept a ``RequestHandler``
and return the current authenticated user.
'''
pass
@property
def login_handler(self) -> type[RequestHandler] | None:
''' A request handler class for a login page.
This property may return None, if ``login_url`` is supplied
instead.
If a class is returned, it must be a subclass of RequestHandler,
which will used for the endpoint specified by ``logout_url``
'''
pass
@property
def login_url(self) -> str | None:
''' A URL to redirect unauthenticated users to for login.
This property may return None, if a ``get_login_url`` function is
supplied instead.
'''
pass
@property
def logout_handler(self) -> type[RequestHandler] | None:
''' A request handler class for a logout page.
This property may return None.
If a class is returned, it must be a subclass of RequestHandler,
which will used for the endpoint specified by ``logout_url``
'''
pass
@property
def logout_url(self) -> str | None:
''' A URL to redirect authenticated users to for logout.
This property may return None.
'''
pass
def _validate(self) -> None:
if self.get_user and self.get_user_async:
raise ValueError("Only one of get_user or get_user_async should be supplied")
if (self.get_user or self.get_user_async) and not (self.login_url or self.get_login_url):
raise ValueError("When user authentication is enabled, one of login_url or get_login_url must be supplied")
if self.login_url and self.get_login_url:
raise ValueError("At most one of login_url or get_login_url should be supplied")
if self.login_handler and self.get_login_url:
raise ValueError("LoginHandler cannot be used with a get_login_url() function")
if self.login_handler and not issubclass(self.login_handler, RequestHandler):
raise ValueError("LoginHandler must be a Tornado RequestHandler")
if self.login_url and not probably_relative_url(self.login_url):
raise ValueError("LoginHandler can only be used with a relative login_url")
if self.logout_handler and not issubclass(self.logout_handler, RequestHandler):
raise ValueError("LogoutHandler must be a Tornado RequestHandler")
if self.logout_url and not probably_relative_url(self.logout_url):
raise ValueError("LogoutHandler can only be used with a relative logout_url")
[docs]
class AuthModule(AuthProvider):
''' An AuthProvider configured from a Python module.
The following properties return the corresponding values from the module if
they exist, or None otherwise:
* ``get_login_url``,
* ``get_user``
* ``get_user_async``
* ``login_url``
* ``logout_url``
The ``login_handler`` property will return a ``LoginHandler`` class from the
module, or None otherwise.
The ``logout_handler`` property will return a ``LogoutHandler`` class from
the module, or None otherwise.
'''
def __init__(self, module_path: PathLike) -> None:
if not isfile(module_path):
raise ValueError(f"no file exists at module_path: {module_path!r}")
self._module = load_auth_module(module_path)
super().__init__()
@property
def get_user(self):
return getattr(self._module, 'get_user', None)
@property
def get_user_async(self):
return getattr(self._module, 'get_user_async', None)
@property
def login_url(self):
return getattr(self._module, 'login_url', None)
@property
def get_login_url(self):
return getattr(self._module, 'get_login_url', None)
@property
def login_handler(self):
return getattr(self._module, 'LoginHandler', None)
@property
def logout_url(self):
return getattr(self._module, 'logout_url', None)
@property
def logout_handler(self):
return getattr(self._module, 'LogoutHandler', None)
[docs]
class NullAuth(AuthProvider):
''' A default no-auth AuthProvider.
All of the properties of this provider return None.
'''
@property
def get_user(self):
return None
@property
def get_user_async(self):
return None
@property
def login_url(self):
return None
@property
def get_login_url(self):
return None
@property
def login_handler(self):
return None
@property
def logout_url(self):
return None
@property
def logout_handler(self):
return None
#-----------------------------------------------------------------------------
# Dev API
#-----------------------------------------------------------------------------
def load_auth_module(module_path: PathLike) -> ModuleType:
''' Load a Python source file at a given path as a module.
Arguments:
module_path (str): path to a Python source file
Returns
module
'''
module_name = "bokeh.auth_" + make_globally_unique_id().replace('-', '')
spec = importlib.util.spec_from_file_location(module_name, module_path)
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)
return module
def probably_relative_url(url: str) -> bool:
''' Return True if a URL is not one of the common absolute URL formats.
Arguments:
url (str): a URL string
Returns
bool
'''
return not url.startswith(("http://", "https://", "//"))
#-----------------------------------------------------------------------------
# Private API
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
