Source code for

#!/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
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  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 six
import sys
import traceback
import types

from . import docs
from girder import events, logger
from girder.constants import SettingKey, TerminalColor, TokenScope
from girder.models.model_base import AccessException, GirderException, \
from girder.utility.model_importer import ModelImporter
from girder.utility import config
from six.moves import range

[docs]def getApiUrl(url=None): """ In a request thread, call this to get the path to the root of the REST API. The returned path does *not* end in a forward slash. :param url: URL from which to extract the base URL. If not specified, uses `cherrypy.url()` """ url = url or cherrypy.url() idx = url.find('/api/v1') if idx < 0: raise GirderException('Could not determine API root in %s.' % url) return url[:idx + 7]
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(returnToken=False, *args, **kwargs): if not returnToken and hasattr(cherrypy.request, 'girderUser'): return cherrypy.request.girderUser user = fun(returnToken, *args, **kwargs) if type(user) is tuple: setattr(cherrypy.request, 'girderUser', user[0]) else: setattr(cherrypy.request, 'girderUser', user) return user return inner def _cacheAuthToken(fun): """ This decorator for getCurrentToken ensures that the token lookup is only performed once per request, and is cached on the request for subsequent calls to getCurrentToken(). """ def inner(*args, **kwargs): if hasattr(cherrypy.request, 'girderToken'): return cherrypy.request.girderToken token = fun(*args, **kwargs) setattr(cherrypy.request, 'girderToken', token) return token return inner @_cacheAuthToken def getCurrentToken(allowCookie=False): """ Returns the current valid token object that was passed via the token header or parameter, or None if no valid token was passed. :param allowCookie: Normally, authentication via cookie is disallowed to protect against CSRF attacks. If you want to expose an endpoint that can be authenticated with a token passed in the Cookie, set this to True. This should only be used on read-only operations that will not make any changes to data on the server, and only in cases where the user agent behavior makes passing custom headers infeasible, such as downloading data to disk in the browser. :type allowCookie: bool """ 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'] elif allowCookie and 'girderToken' in cherrypy.request.cookie: tokenStr = cherrypy.request.cookie['girderToken'].value if not tokenStr: return None return ModelImporter.model('token').load(tokenStr, force=True, objectId=False) @_cacheAuthUser def getCurrentUser(returnToken=False): """ Returns the currently authenticated user based on the token header or parameter. :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 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] token = getCurrentToken() def retVal(user, token): if returnToken: return (user, token) else: return user if (token is None or token['expires'] < datetime.datetime.utcnow() or 'userId' not in token): return retVal(None, token) else: try: ensureTokenScopes(token, TokenScope.USER_AUTH) except AccessException: return retVal(None, token) user = ModelImporter.model('user').load(token['userId'], force=True) return retVal(user, token)
[docs]def requireAdmin(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.')
[docs]def getBodyJson(): """ For requests that are expected to contain a JSON body, this returns the parsed value, or raises a :class:`` for invalid JSON. """ try: return json.loads('utf8')) except ValueError: raise RestException('Invalid JSON passed in request body.')
[docs]class loadmodel(object): """ 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. If None is passed, this will map the parameter named "id" to a kwarg named the same as the "model" parameter. :type map: dict or None :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=None, model=None, plugin='_core', level=None, force=False): if map is None: = {'id': model} else: = map self.model = ModelImporter.model(model, plugin) self.level = level self.force = force def _getIdValue(self, kwargs, idParam): if idParam in kwargs: return kwargs.pop(idParam) elif idParam in kwargs['params']: return kwargs['params'].pop(idParam) else: raise RestException('No ID parameter passed: ' + idParam) def __call__(self, fun): @six.wraps(fun) def wrapped(*args, **kwargs): for raw, converted in six.iteritems( id = self._getIdValue(kwargs, raw) if self.force: kwargs[converted] = self.model.load(id, force=True) elif self.level is not None: kwargs[converted] = self.model.load( id=id, level=self.level, user=getCurrentUser()) else: kwargs[converted] = self.model.load(id) if kwargs[converted] is None: raise RestException('Invalid {} id ({}).' .format(, id)) return fun(*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(' ', '&nbsp;').replace('\n', '<br />') resp = '<div style="font-family:monospace;">%s</div>' % resp return resp.encode('utf8') # 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, sort_keys=True, default=str).encode('utf8')
[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. """ @six.wraps(fun) def endpointDecorator(self, *args, **kwargs): # Note that the cyclomatic complexity of this function crosses our # flake8 configuration threshold. Because it is largely exception # handling, I think that breaking it into smaller functions actually # reduces readability and maintainability. To work around this, some # simple branches have been marked to be skipped in the cyclomatic # analysis. _setCommonCORSHeaders() cherrypy.lib.caching.expires(0) try: val = fun(self, args, kwargs) # If this is a partial response, we set the status appropriately if 'Content-Range' in cherrypy.response.headers: cherrypy.response.status = 206 if isinstance(val, types.FunctionType): # If the endpoint returned a function, we assume it's a # generator function for a streaming response. = True return val() if isinstance(val, cherrypy.lib.file_generator): # Don't do any post-processing of static files 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 GirderException as e: # Handle general girder exceptions logger.exception('500 Error') cherrypy.response.status = 500 val = {'message': e.message, 'type': 'girder'} if e.identifier is not None: val['identifier'] = e.identifier 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: # flake8: noqa raise except Exception: # 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]def ensureTokenScopes(token, scope): """ Call this to validate a token scope for endpoints that require tokens other than a user authentication token. Raises an AccessException if the required scopes are not allowed by the given token. :param token: The token object used in the request. :type token: dict :param scope: The required scope or set of scopes. :type scope: str or list of str """ tokenModel = ModelImporter.model('token') if not tokenModel.hasScope(token, scope): setattr(cherrypy.request, 'girderUser', None) if isinstance(scope, six.string_types): scope = (scope,) raise AccessException( 'Invalid token scope.\nRequired: {}.\nAllowed: {}' .format(' '.join(scope), ' '.join(tokenModel.getAllowedScopes(token))))
def _setCommonCORSHeaders(): """ Set CORS headers that should be passed back with either a preflight OPTIONS or a simple CORS request. We set these headers anytime there is an Origin header present since browsers will simply ignore them if the request is not cross-origin. """ if not cherrypy.request.headers.get('origin'): # If there is no origin header, this is not a cross origin request return origins = ModelImporter.model('setting').get(SettingKey.CORS_ALLOW_ORIGIN) if origins: cherrypy.response.headers['Access-Control-Allow-Origin'] = origins cherrypy.response.headers['Access-Control-Allow-Credentials'] = 'true'
[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 self.message = message Exception.__init__(self, message)
[docs]class Resource(ModelImporter): """ All REST resources should inherit from this class, which provides utilities for adding resources/routes to the REST API. """ exposed = True
[docs] 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', 'PATCH' :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: tuple :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 :param resource: The name of the resource at the root of this route. """ 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 range(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)))
[docs] def removeRoute(self, method, route, handler=None, resource=None): """ Remove a route from the handler and documentation. :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 called for the route; this is necessary to remove the documentation. :type handler: function :param resource: the name of the resource at the root of this route. """ if not hasattr(self, '_routes'): return nLengthRoutes = self._routes[method.lower()][len(route)] for i in range(len(nLengthRoutes)): if nLengthRoutes[i][0] == route: del nLengthRoutes[i] break # Remove the api doc if resource is None and hasattr(self, 'resourceName'): resource = self.resourceName elif resource is None: resource = handler.__module__.rsplit('.', 1)[-1] if handler and hasattr(handler, 'description'): if handler.description is not None: docs.removeRouteDocs( resource=resource, route=route, method=method, info=handler.description.asDict(), handler=handler)
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 range(len(a)): if a[i][0] != ':' and b[i][0] == ':': return True return False
[docs] 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['params'], and the matched route tokens are passed in as dict items of, so in the previous example 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.: ```` Note: You will normally not need to call this method directly, as it is called by the internals of this class during the routing process. :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: if hasattr(handler, 'cookieAuth') and handler.cookieAuth: getCurrentToken(allowCookie=True) 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, pre=self._defaultAccess) 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
[docs] 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, six.string_types): required = (required,) for param in required: if param not in provided: raise RestException("Parameter '%s' is required." % param)
[docs] 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')
[docs] 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. """ return requireAdmin(user)
[docs] def getPagingParameters(self, params, defaultSortField=None, defaultSortDir=pymongo.ASCENDING): """ 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', defaultSortDir)) if 'sort' in params: sort = [(params['sort'].strip(), sortdir)] elif type(defaultSortField) is str: sort = [(defaultSortField, sortdir)] else: sort = None return limit, offset, sort
[docs] def ensureTokenScopes(self, scope): """ Ensure that the token passed to this request is authorized for the designated scope or set of scopes. Raises an AccessException if not. :param scope: A scope or set of scopes that is required. :type scope: str or list of str """ ensureTokenScopes(getCurrentToken(), scope)
[docs] def getBodyJson(self): """ Bound wrapper for :func:``. """ return getBodyJson()
[docs] def getCurrentToken(self): """ Returns the current valid token object that was passed via the token header or parameter, or None if no valid token was passed. """ return getCurrentToken()
[docs] def getCurrentUser(self, returnToken=False): """ Returns the currently authenticated user based on the token header or parameter. :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 token is invalid or expired. If returnToken=True, returns a tuple of (user, token). """ return getCurrentUser(returnToken)
[docs] def sendAuthTokenCookie(self, user, scope=None): """ Helper method to send the authentication cookie """ days = int(self.model('setting').get(SettingKey.COOKIE_LIFETIME)) token = self.model('token').createToken(user, days=days, scope=scope) cookie = cherrypy.response.cookie cookie['girderToken'] = str(token['_id']) cookie['girderToken']['path'] = '/' cookie['girderToken']['expires'] = days * 3600 * 24 return token
[docs] def deleteAuthTokenCookie(self): """ Helper method to kill the authentication cookie """ cookie = cherrypy.response.cookie cookie['girderToken'] = '' cookie['girderToken']['path'] = '/' cookie['girderToken']['expires'] = 0 # This is NOT wrapped in an endpoint decorator; we don't want that behavior
def OPTIONS(self, *path, **param): _setCommonCORSHeaders() cherrypy.lib.caching.expires(0) allowHeaders = self.model('setting').get(SettingKey.CORS_ALLOW_HEADERS) allowMethods = self.model('setting').get(SettingKey.CORS_ALLOW_METHODS)\ or 'GET, POST, PUT, HEAD, DELETE' cherrypy.response.headers['Access-Control-Allow-Methods'] = allowMethods cherrypy.response.headers['Access-Control-Allow-Headers'] = allowHeaders @endpoint def DELETE(self, path, params): # DELETE bodies are optional. Assume if we have a content-length, then # there is a body that should be processed. if 'Content-Length' in cherrypy.request.headers: cherrypy.request.body.process() params.update(cherrypy.request.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): method = 'POST' # When using a POST request, the method can be overridden and really be # something else. There seem to be three different 'standards' on how # to do this (see # x-http-header-method-override-and-rest.html). We might as well # support all three. for key in ('X-HTTP-Method-Override', 'X-HTTP-Method', 'X-Method-Override'): if key in cherrypy.request.headers: method = cherrypy.request.headers[key] return self.handleRoute(method, path, params) @endpoint def PUT(self, path, params): return self.handleRoute('PUT', path, params) @endpoint def PATCH(self, path, params): return self.handleRoute('PATCH', path, params) @staticmethod def _defaultAccess(handler, **kwargs): """ This is the pre-event handler callback for the events that are triggered before default handling of a REST request. Since such an event handler could accidentally circumvent the access level of the default handler, we enforce that handlers of these event types must also specify their own access level, or else default to the strictest level (admin) just like the core route handlers. This allows plugins to potentially override the default level, but makes sure they don't accidentally lower the access level for a given route. """ if not hasattr(handler, 'accessLevel'): requireAdmin(getCurrentUser()) # An instance of Resource that can be shared by boundHandlers for efficiency
_sharedContext = Resource()
[docs]class boundHandler(object): """ This decorator allows unbound functions to be conveniently added as route handlers to existing :py:class:`` instances. With no arguments, this uses a shared, generic ``Resource`` instance as the context. If you need a specific instance, pass that as the ``ctx`` arg, for instance if you need to reference the resource name or any other properties specific to a Resource subclass. Plugins that add new routes to existing API resources are encouraged to use this to gain access to bound convenience methods like ``self.model``, ``self.boolParam``, ``self.requireParams``, etc. """ def __init__(self, ctx=None): self.ctx = ctx or _sharedContext def __call__(self, fn): @six.wraps(fn) def wrapped(*args, **kwargs): return fn(self.ctx, *args, **kwargs) return wrapped