#!/usr/bin/env python
# -*- coding: utf-8 -*-
###############################################################################
# Copyright 2013 Kitware Inc.
#
# Licensed under the Apache License, Version 2.0 ( the "License" );
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
###############################################################################
import cherrypy
import collections
import datetime
import functools
import json
import pymongo
import sys
import traceback
import types
from . import docs
from girder import events, logger
from girder.constants import SettingKey, TerminalColor
from girder.models.model_base import AccessException, ValidationException
from girder.utility.model_importer import ModelImporter
from girder.utility import config
def _cacheAuthUser(fun):
"""
This decorator for getCurrentUser ensures that the authentication procedure
is only performed once per request, and is cached on the request for
subsequent calls to getCurrentUser().
"""
def inner(self, returnToken=False, *args, **kwargs):
if not returnToken and hasattr(cherrypy.request, 'girderUser'):
return cherrypy.request.girderUser
user = fun(self, returnToken, *args, **kwargs)
if type(user) is tuple:
setattr(cherrypy.request, 'girderUser', user[0])
else:
setattr(cherrypy.request, 'girderUser', user)
return user
return inner
[docs]class loadmodel(ModelImporter):
"""
This is a decorator that can be used to load a model based on an ID param.
For access controlled models, it will check authorization for the current
user. The underlying function is called with a modified set of keyword
arguments that is transformed by the "map" parameter of this decorator.
:param map: Map of incoming parameter name to corresponding model arg name.
:type map: dict
:param model: The model name, e.g. 'folder'
:type model: str
:param plugin: Plugin name, if loading a plugin model.
:type plugin: str
:param level: Access level, if this is an access controlled model.
:type level: AccessType
"""
def __init__(self, map, model, plugin='_core', level=None):
self.map = map
self.model = self.model(model, plugin)
self.level = level
def __call__(self, fun):
@functools.wraps(fun)
def wrapped(wrappedSelf, *args, **kwargs):
for raw, converted in self.map.iteritems():
if self.level is not None:
user = wrappedSelf.getCurrentUser()
kwargs[converted] = self.model.load(
id=kwargs[raw], level=self.level, user=user)
else:
kwargs[converted] = self.model.load(kwargs[raw])
if kwargs[converted] is None:
raise RestException('Invalid {} id ({}).'
.format(self.model.name, kwargs[raw]))
del kwargs[raw]
return fun(wrappedSelf, *args, **kwargs)
return wrapped
def _createResponse(val):
"""
Helper that encodes the response according to the requested "Accepts"
header from the client. Currently supports "application/json" and
"text/html".
"""
accepts = cherrypy.request.headers.elements('Accept')
for accept in accepts:
if accept.value == 'application/json':
break
elif accept.value == 'text/html': # pragma: no cover
# Pretty-print and HTML-ify the response for the browser
cherrypy.response.headers['Content-Type'] = 'text/html'
resp = json.dumps(val, indent=4, sort_keys=True,
separators=(',', ': '), default=str)
resp = resp.replace(' ', ' ').replace('\n', '<br />')
resp = '<div style="font-family:monospace;">%s</div>' % resp
return resp
# Default behavior will just be normal JSON output. Keep this
# outside of the loop body in case no Accept header is passed.
cherrypy.response.headers['Content-Type'] = 'application/json'
return json.dumps(val, default=str)
[docs]def endpoint(fun):
"""
REST HTTP method endpoints should use this decorator. It converts the return
value of the underlying method to the appropriate output format and
sets the relevant response headers. It also handles RestExceptions,
which are 400-level exceptions in the REST endpoints, AccessExceptions
resulting from access denial, and also handles any unexpected errors
using 500 status and including a useful traceback in those cases.
If you want a streamed response, simply return a generator function
from the inner method.
"""
@functools.wraps(fun)
def endpointDecorator(self, *args, **kwargs):
try:
val = fun(self, args, kwargs)
if isinstance(val, types.FunctionType):
# If the endpoint returned a function, we assume it's a
# generator function for a streaming response.
cherrypy.response.stream = True
return val()
except RestException as e:
# Handle all user-error exceptions from the rest layer
cherrypy.response.status = e.code
val = {'message': e.message, 'type': 'rest'}
if e.extra is not None:
val['extra'] = e.extra
except AccessException as e:
# Permission exceptions should throw a 401 or 403, depending
# on whether the user is logged in or not
if self.getCurrentUser() is None:
cherrypy.response.status = 401
else:
cherrypy.response.status = 403
logger.exception('403 Error')
val = {'message': e.message, 'type': 'access'}
except ValidationException as e:
cherrypy.response.status = 400
val = {'message': e.message, 'type': 'validation'}
if e.field is not None:
val['field'] = e.field
except cherrypy.HTTPRedirect:
raise
except:
# These are unexpected failures; send a 500 status
logger.exception('500 Error')
cherrypy.response.status = 500
t, value, tb = sys.exc_info()
val = {'message': '%s: %s' % (t.__name__, repr(value)),
'type': 'internal'}
curConfig = config.getConfig()
if curConfig['server']['mode'] != 'production':
# Unless we are in production mode, send a traceback too
val['trace'] = traceback.extract_tb(tb)
return _createResponse(val)
return endpointDecorator
[docs]class RestException(Exception):
"""
Throw a RestException in the case of any sort of incorrect
request (i.e. user/client error). Login and permission failures
should set a 403 code; almost all other validation errors
should use status 400, which is the default.
"""
def __init__(self, message, code=400, extra=None):
self.code = code
self.extra = extra
Exception.__init__(self, message)
class Resource(ModelImporter):
exposed = True
def route(self, method, route, handler, nodoc=False, resource=None):
"""
Define a route for your REST resource.
:param method: The HTTP method, e.g. 'GET', 'POST', 'PUT'
:type method: str
:param route: The route, as a list of path params relative to the
resource root. Elements of this list starting with ':' are assumed to
be wildcards.
:type route: list
:param handler: The method to be called if the route and method are
matched by a request. Wildcards in the route will be expanded and
passed as kwargs with the same name as the wildcard identifier.
:type handler: function
:param nodoc: If your route intentionally provides no documentation,
set this to True to disable the warning on startup.
:type nodoc: bool
"""
if not hasattr(self, '_routes'):
self._routes = collections.defaultdict(
lambda: collections.defaultdict(list))
# Insertion sort to maintain routes in required order.
nLengthRoutes = self._routes[method.lower()][len(route)]
for i in xrange(0, len(nLengthRoutes)):
if self._shouldInsertRoute(route, nLengthRoutes[i][0]):
nLengthRoutes.insert(i, (route, handler))
break
else:
nLengthRoutes.append((route, handler))
# Now handle the api doc if the handler has any attached
if resource is None and hasattr(self, 'resourceName'):
resource = self.resourceName
elif resource is None:
resource = handler.__module__.rsplit('.', 1)[-1]
if hasattr(handler, 'description'):
if handler.description is not None:
docs.addRouteDocs(
resource=resource, route=route, method=method,
info=handler.description.asDict(), handler=handler)
elif not nodoc:
routePath = '/'.join([resource] + list(route))
print TerminalColor.warning(
'WARNING: No description docs present for route {} {}'
.format(method, routePath))
# Warn if there is no access decorator on the handler function
if not hasattr(handler, 'accessLevel'):
routePath = '/'.join([resource] + list(route))
print TerminalColor.warning(
'WARNING: No access level specified for route {} {}'
.format(method, routePath))
def _shouldInsertRoute(self, a, b):
"""
Return bool representing whether route a should go before b. Checks by
comparing each token in order and making sure routes with literals in
forward positions come before routes with wildcards in those positions.
"""
for i in xrange(0, len(a)):
if a[i][0] != ':' and b[i][0] == ':':
return True
return False
def handleRoute(self, method, path, params):
"""
Match the requested path to its corresponding route, and calls the
handler for that route with the appropriate kwargs. If no route
matches the path requested, throws a RestException.
This method fires two events for each request if a matching route is
found. The names of these events are derived from the route matched by
the request. As an example, if the user calls GET /api/v1/item/123,
the following two events would be fired:
rest.get.item/:id.before
would be fired prior to calling the default API function, and
rest.get.item/:id.after
would be fired after the route handler returns. The query params are
passed in the info of the before and after event handlers as
event.info['params'], and the matched route tokens are passed in
as dict items of event.info, so in the previous example event.info would
also contain an 'id' key with the value of 123. For endpoints with empty
sub-routes, the trailing slash is omitted from the event name, e.g.:
rest.post.group.before
:param method: The HTTP method of the current request.
:type method: str
:param path: The path params of the request.
:type path: list
"""
if not self._routes:
raise Exception('No routes defined for resource')
method = method.lower()
for route, handler in self._routes[method][len(path)]:
kwargs = self._matchRoute(path, route)
if kwargs is not False:
kwargs['params'] = params
# Add before call for the API method. Listeners can return
# their own responses by calling preventDefault() and
# adding a response on the event.
if hasattr(self, 'resourceName'):
resource = self.resourceName
else:
resource = handler.__module__.rsplit('.', 1)[-1]
routeStr = '/'.join((resource, '/'.join(route))).rstrip('/')
eventPrefix = '.'.join(('rest', method, routeStr))
event = events.trigger('.'.join((eventPrefix, 'before')),
kwargs)
if event.defaultPrevented and len(event.responses) > 0:
val = event.responses[0]
else:
self._defaultAccess(handler)
val = handler(**kwargs)
# Fire the after-call event that has a chance to augment the
# return value of the API method that was called. You can
# reassign the return value completely by adding a response to
# the event and calling preventDefault() on it.
kwargs['returnVal'] = val
event = events.trigger('.'.join((eventPrefix, 'after')), kwargs)
if event.defaultPrevented and len(event.responses) > 0:
val = event.responses[0]
return val
raise RestException('No matching route for "{} {}"'.format(
method.upper(), '/'.join(path)))
def _matchRoute(self, path, route):
"""
Helper function that attempts to match the requested path with a
given route specification. Returns False if the requested path does
not match the route. If it does match, this will return the dict of
kwargs that should be passed to the underlying handler, based on the
wildcard tokens of the route.
:param path: The requested path.
:type path: list
:param route: The route specification to match against.
:type route: list
"""
wildcards = {}
for i in range(0, len(route)):
if route[i][0] == ':': # Wildcard token
wildcards[route[i][1:]] = path[i]
elif route[i] != path[i]: # Exact match token
return False
return wildcards
def requireParams(self, required, provided):
"""
Throws an exception if any of the parameters in the required iterable
is not found in the provided parameter set.
:param required: An iterable of required params, or if just one is
required, you can simply pass it as a string.
:type required: list, tuple, or str
:param provided: The list of provided parameters.
:type provided: dict
"""
if isinstance(required, basestring):
required = (required,)
for param in required:
if param not in provided:
raise RestException("Parameter '%s' is required." % param)
def boolParam(self, key, params, default=None):
"""
Coerce a parameter value from a str to a bool. This function is case
insensitive. The following string values will be interpreted as True:
'true'
'on'
'1'
'yes'
All other strings will be interpreted as False. If the given param
is not passed at all, returns the value specified by the default arg.
"""
if key not in params:
return default
val = params[key]
if type(val) is bool:
return val
return val.lower().strip() in ('true', 'on', '1', 'yes')
def requireAdmin(self, user):
"""
Calling this on a user will ensure that they have admin rights.
If not, raises an AccessException.
:param user: The user to check admin flag on.
:type user: dict.
:raises AccessException: If the user is not an administrator.
"""
if user is None or user.get('admin', False) is not True:
raise AccessException('Administrator access required.')
def getPagingParameters(self, params, defaultSortField=None):
"""
Pass the URL parameters into this function if the request is for a
list of resources that should be paginated. It will return a tuple of
the form (limit, offset, sort) whose values should be passed directly
into the model methods that are finding the resources. If the client
did not pass the parameters, this always uses the same defaults of
limit=50, offset=0, sort='name', sortdir=pymongo.ASCENDING=1.
:param params: The URL query parameters.
:type params: dict
:param defaultSortField: If the client did not pass a 'sort' parameter,
set this to choose a default sort field. If None, the results will
be returned unsorted.
:type defaultSortField: str or None
"""
offset = int(params.get('offset', 0))
limit = int(params.get('limit', 50))
sortdir = int(params.get('sortdir', pymongo.ASCENDING))
if 'sort' in params:
sort = [(params['sort'].strip(), sortdir)]
elif type(defaultSortField) is str:
sort = [(defaultSortField, sortdir)]
else:
sort = None
return limit, offset, sort
@_cacheAuthUser
def getCurrentUser(self, returnToken=False):
"""
Returns the current user from the long-term cookie token.
:param returnToken: Whether we should return a tuple that also contains
the token.
:type returnToken: bool
:returns: The user document from the database, or None if the user
is not logged in or the cookie token is invalid or expired.
If returnToken=True, returns a tuple of (user, token).
"""
event = events.trigger('auth.user.get')
if event.defaultPrevented and len(event.responses) > 0:
return event.responses[0]
tokenStr = None
if 'token' in cherrypy.request.params: # Token as a parameter
tokenStr = cherrypy.request.params.get('token')
elif 'Girder-Token' in cherrypy.request.headers:
tokenStr = cherrypy.request.headers['Girder-Token']
if not tokenStr:
return (None, None) if returnToken else None
token = self.model('token').load(tokenStr, force=True,
objectId=False)
if token is None or token['expires'] < datetime.datetime.utcnow():
return (None, token) if returnToken else None
else:
user = self.model('user').load(token['userId'], force=True)
return (user, token) if returnToken else user
def sendAuthTokenCookie(self, user):
""" Helper method to send the authentication cookie """
days = int(self.model('setting').get(SettingKey.COOKIE_LIFETIME))
token = self.model('token').createToken(user, days=days)
cookie = cherrypy.response.cookie
cookie['girderToken'] = str(token['_id'])
cookie['girderToken']['path'] = '/'
cookie['girderToken']['expires'] = days * 3600 * 24
return token
def deleteAuthTokenCookie(self):
""" Helper method to kill the authentication cookie """
cookie = cherrypy.response.cookie
cookie['girderToken'] = ''
cookie['girderToken']['path'] = '/'
cookie['girderToken']['expires'] = 0
@endpoint
def DELETE(self, path, params):
return self.handleRoute('DELETE', path, params)
@endpoint
def GET(self, path, params):
return self.handleRoute('GET', path, params)
@endpoint
def POST(self, path, params):
return self.handleRoute('POST', path, params)
@endpoint
def PUT(self, path, params):
return self.handleRoute('PUT', path, params)
def _defaultAccess(self, fun):
"""
If a function wasn't wrapped by one of the security decorators, check
the default access rights (admin required).
"""
if not hasattr(fun, 'accessLevel'):
self.requireAdmin(self.getCurrentUser())