"""Base Tornado handlers for the notebook. Authors: * Brian Granger """ #----------------------------------------------------------------------------- # Copyright (C) 2011 The IPython Development Team # # Distributed under the terms of the BSD License. The full license is in # the file COPYING, distributed as part of this software. #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Imports #----------------------------------------------------------------------------- import datetime import email.utils import functools import hashlib import json import logging import mimetypes import os import stat import sys import threading import traceback from tornado import web from tornado import websocket try: from tornado.log import app_log except ImportError: app_log = logging.getLogger() from IPython.config import Application from IPython.external.decorator import decorator from IPython.utils.path import filefind from IPython.utils.jsonutil import date_default #----------------------------------------------------------------------------- # Monkeypatch for Tornado <= 2.1.1 - Remove when no longer necessary! #----------------------------------------------------------------------------- # Google Chrome, as of release 16, changed its websocket protocol number. The # parts tornado cares about haven't really changed, so it's OK to continue # accepting Chrome connections, but as of Tornado 2.1.1 (the currently released # version as of Oct 30/2011) the version check fails, see the issue report: # https://github.com/facebook/tornado/issues/385 # This issue has been fixed in Tornado post 2.1.1: # https://github.com/facebook/tornado/commit/84d7b458f956727c3b0d6710 # Here we manually apply the same patch as above so that users of IPython can # continue to work with an officially released Tornado. We make the # monkeypatch version check as narrow as possible to limit its effects; once # Tornado 2.1.1 is no longer found in the wild we'll delete this code. import tornado if tornado.version_info <= (2,1,1): def _execute(self, transforms, *args, **kwargs): from tornado.websocket import WebSocketProtocol8, WebSocketProtocol76 self.open_args = args self.open_kwargs = kwargs # The difference between version 8 and 13 is that in 8 the # client sends a "Sec-Websocket-Origin" header and in 13 it's # simply "Origin". if self.request.headers.get("Sec-WebSocket-Version") in ("7", "8", "13"): self.ws_connection = WebSocketProtocol8(self) self.ws_connection.accept_connection() elif self.request.headers.get("Sec-WebSocket-Version"): self.stream.write(tornado.escape.utf8( "HTTP/1.1 426 Upgrade Required\r\n" "Sec-WebSocket-Version: 8\r\n\r\n")) self.stream.close() else: self.ws_connection = WebSocketProtocol76(self) self.ws_connection.accept_connection() websocket.WebSocketHandler._execute = _execute del _execute #----------------------------------------------------------------------------- # Top-level handlers #----------------------------------------------------------------------------- class RequestHandler(web.RequestHandler): """RequestHandler with default variable setting.""" def render(*args, **kwargs): kwargs.setdefault('message', '') return web.RequestHandler.render(*args, **kwargs) class AuthenticatedHandler(RequestHandler): """A RequestHandler with an authenticated user.""" def clear_login_cookie(self): self.clear_cookie(self.cookie_name) def get_current_user(self): user_id = self.get_secure_cookie(self.cookie_name) # For now the user_id should not return empty, but it could eventually if user_id == '': user_id = 'anonymous' if user_id is None: # prevent extra Invalid cookie sig warnings: self.clear_login_cookie() if not self.login_available: user_id = 'anonymous' return user_id @property def cookie_name(self): default_cookie_name = 'username-{host}'.format( host=self.request.host, ).replace(':', '-') return self.settings.get('cookie_name', default_cookie_name) @property def password(self): """our password""" return self.settings.get('password', '') @property def logged_in(self): """Is a user currently logged in? """ user = self.get_current_user() return (user and not user == 'anonymous') @property def login_available(self): """May a user proceed to log in? This returns True if login capability is available, irrespective of whether the user is already logged in or not. """ return bool(self.settings.get('password', '')) class IPythonHandler(AuthenticatedHandler): """IPython-specific extensions to authenticated handling Mostly property shortcuts to IPython-specific settings. """ @property def config(self): return self.settings.get('config', None) @property def log(self): """use the IPython log by default, falling back on tornado's logger""" if Application.initialized(): return Application.instance().log else: return app_log @property def use_less(self): """Use less instead of css in templates""" return self.settings.get('use_less', False) #--------------------------------------------------------------- # URLs #--------------------------------------------------------------- @property def ws_url(self): """websocket url matching the current request By default, this is just `''`, indicating that it should match the same host, protocol, port, etc. """ return self.settings.get('websocket_url', '') @property def mathjax_url(self): return self.settings.get('mathjax_url', '') @property def base_project_url(self): return self.settings.get('base_project_url', '/') @property def base_kernel_url(self): return self.settings.get('base_kernel_url', '/') #--------------------------------------------------------------- # Manager objects #--------------------------------------------------------------- @property def kernel_manager(self): return self.settings['kernel_manager'] @property def notebook_manager(self): return self.settings['notebook_manager'] @property def cluster_manager(self): return self.settings['cluster_manager'] @property def session_manager(self): return self.settings['session_manager'] @property def project_dir(self): return self.notebook_manager.notebook_dir #--------------------------------------------------------------- # template rendering #--------------------------------------------------------------- def get_template(self, name): """Return the jinja template object for a given name""" return self.settings['jinja2_env'].get_template(name) def render_template(self, name, **ns): ns.update(self.template_namespace) template = self.get_template(name) return template.render(**ns) @property def template_namespace(self): return dict( base_project_url=self.base_project_url, base_kernel_url=self.base_kernel_url, logged_in=self.logged_in, login_available=self.login_available, use_less=self.use_less, ) def get_json_body(self): """Return the body of the request as JSON data.""" if not self.request.body: return None # Do we need to call body.decode('utf-8') here? body = self.request.body.strip().decode(u'utf-8') try: model = json.loads(body) except Exception: self.log.debug("Bad JSON: %r", body) self.log.error("Couldn't parse JSON", exc_info=True) raise web.HTTPError(400, u'Invalid JSON in body of request') return model class AuthenticatedFileHandler(IPythonHandler, web.StaticFileHandler): """static files should only be accessible when logged in""" @web.authenticated def get(self, path): if os.path.splitext(path)[1] == '.ipynb': name = os.path.basename(path) self.set_header('Content-Type', 'application/json') self.set_header('Content-Disposition','attachment; filename="%s"' % name) return web.StaticFileHandler.get(self, path) def json_errors(method): """Decorate methods with this to return GitHub style JSON errors. This should be used on any JSON API on any handler method that can raise HTTPErrors. This will grab the latest HTTPError exception using sys.exc_info and then: 1. Set the HTTP status code based on the HTTPError 2. Create and return a JSON body with a message field describing the error in a human readable form. """ @functools.wraps(method) def wrapper(self, *args, **kwargs): try: result = method(self, *args, **kwargs) except web.HTTPError as e: status = e.status_code message = e.log_message self.set_status(e.status_code) self.finish(json.dumps(dict(message=message))) except Exception: self.log.error("Unhandled error in API request", exc_info=True) status = 500 message = "Unknown server error" t, value, tb = sys.exc_info() self.set_status(status) tb_text = ''.join(traceback.format_exception(t, value, tb)) reply = dict(message=message, traceback=tb_text) self.finish(json.dumps(reply)) else: return result return wrapper #----------------------------------------------------------------------------- # File handler #----------------------------------------------------------------------------- # to minimize subclass changes: HTTPError = web.HTTPError class FileFindHandler(web.StaticFileHandler): """subclass of StaticFileHandler for serving files from a search path""" _static_paths = {} # _lock is needed for tornado < 2.2.0 compat _lock = threading.Lock() # protects _static_hashes def initialize(self, path, default_filename=None): if isinstance(path, basestring): path = [path] self.roots = tuple( os.path.abspath(os.path.expanduser(p)) + os.path.sep for p in path ) self.default_filename = default_filename @classmethod def locate_file(cls, path, roots): """locate a file to serve on our static file search path""" with cls._lock: if path in cls._static_paths: return cls._static_paths[path] try: abspath = os.path.abspath(filefind(path, roots)) except IOError: # empty string should always give exists=False return '' # os.path.abspath strips a trailing / # it needs to be temporarily added back for requests to root/ if not (abspath + os.path.sep).startswith(roots): raise HTTPError(403, "%s is not in root static directory", path) cls._static_paths[path] = abspath return abspath def get(self, path, include_body=True): path = self.parse_url_path(path) # begin subclass override abspath = self.locate_file(path, self.roots) # end subclass override if os.path.isdir(abspath) and self.default_filename is not None: # need to look at the request.path here for when path is empty # but there is some prefix to the path that was already # trimmed by the routing if not self.request.path.endswith("/"): self.redirect(self.request.path + "/") return abspath = os.path.join(abspath, self.default_filename) if not os.path.exists(abspath): raise HTTPError(404) if not os.path.isfile(abspath): raise HTTPError(403, "%s is not a file", path) stat_result = os.stat(abspath) modified = datetime.datetime.utcfromtimestamp(stat_result[stat.ST_MTIME]) self.set_header("Last-Modified", modified) mime_type, encoding = mimetypes.guess_type(abspath) if mime_type: self.set_header("Content-Type", mime_type) cache_time = self.get_cache_time(path, modified, mime_type) if cache_time > 0: self.set_header("Expires", datetime.datetime.utcnow() + \ datetime.timedelta(seconds=cache_time)) self.set_header("Cache-Control", "max-age=" + str(cache_time)) else: self.set_header("Cache-Control", "public") self.set_extra_headers(path) # Check the If-Modified-Since, and don't send the result if the # content has not been modified ims_value = self.request.headers.get("If-Modified-Since") if ims_value is not None: date_tuple = email.utils.parsedate(ims_value) if_since = datetime.datetime(*date_tuple[:6]) if if_since >= modified: self.set_status(304) return with open(abspath, "rb") as file: data = file.read() hasher = hashlib.sha1() hasher.update(data) self.set_header("Etag", '"%s"' % hasher.hexdigest()) if include_body: self.write(data) else: assert self.request.method == "HEAD" self.set_header("Content-Length", len(data)) @classmethod def get_version(cls, settings, path): """Generate the version string to be used in static URLs. This method may be overridden in subclasses (but note that it is a class method rather than a static method). The default implementation uses a hash of the file's contents. ``settings`` is the `Application.settings` dictionary and ``path`` is the relative location of the requested asset on the filesystem. The returned value should be a string, or ``None`` if no version could be determined. """ # begin subclass override: static_paths = settings['static_path'] if isinstance(static_paths, basestring): static_paths = [static_paths] roots = tuple( os.path.abspath(os.path.expanduser(p)) + os.path.sep for p in static_paths ) try: abs_path = filefind(path, roots) except IOError: app_log.error("Could not find static file %r", path) return None # end subclass override with cls._lock: hashes = cls._static_hashes if abs_path not in hashes: try: f = open(abs_path, "rb") hashes[abs_path] = hashlib.md5(f.read()).hexdigest() f.close() except Exception: app_log.error("Could not open static file %r", path) hashes[abs_path] = None hsh = hashes.get(abs_path) if hsh: return hsh[:5] return None def parse_url_path(self, url_path): """Converts a static URL path into a filesystem path. ``url_path`` is the path component of the URL with ``static_url_prefix`` removed. The return value should be filesystem path relative to ``static_path``. """ if os.path.sep != "/": url_path = url_path.replace("/", os.path.sep) return url_path class TrailingSlashHandler(web.RequestHandler): """Simple redirect handler that strips trailing slashes This should be the first, highest priority handler. """ SUPPORTED_METHODS = ['GET'] def get(self): self.redirect(self.request.uri.rstrip('/')) #----------------------------------------------------------------------------- # URL to handler mappings #----------------------------------------------------------------------------- default_handlers = [ (r".*/", TrailingSlashHandler) ]