Source code for

Utilities for creating bokeh Server instances.
from __future__ import annotations

import asyncio
import datetime as dt
import gc
import html
import importlib
import logging
import os
import pathlib
import signal
import sys
import traceback
import threading
import uuid
import warnings

from collections import OrderedDict
from contextlib import contextmanager
from functools import partial, wraps
from types import FunctionType, MethodType
from typing import (
    TYPE_CHECKING, Any, Callable, Dict, Mapping, Optional, Union
from urllib.parse import urljoin, urlparse

import param
import bokeh
import bokeh.command.util
import tornado

# Bokeh imports
from bokeh.application import Application as BkApplication
from bokeh.application.handlers.code import CodeHandler, _monkeypatch_io, patch_curdoc
from bokeh.application.handlers.function import FunctionHandler
from bokeh.command.util import build_single_handler_application
from bokeh.core.templates import AUTOLOAD_JS
from bokeh.embed.bundle import Script
from bokeh.embed.elements import html_page_for_render_items, script_for_render_items
from bokeh.embed.util import RenderItem
from import curdoc
from bokeh.server.server import Server
from bokeh.server.urls import per_app_patterns
from bokeh.server.views.autoload_js_handler import AutoloadJsHandler as BkAutoloadJsHandler
from bokeh.server.views.doc_handler import DocHandler as BkDocHandler
from bokeh.server.views.static_handler import StaticHandler

# Tornado imports
from tornado.ioloop import IOLoop
from tornado.web import HTTPError, RequestHandler, StaticFileHandler, authenticated
from tornado.wsgi import WSGIContainer

# Internal imports
from ..util import edit_readonly, fullpath
from .document import init_doc, with_lock, unlocked # noqa
from .profile import profile_ctx
from .reload import autoreload_watcher
from .resources import (
    BASE_TEMPLATE, COMPONENT_PATH, Resources, bundle_resources, component_rel_path
from .state import set_curdoc, state

logger = logging.getLogger(__name__)

    from bokeh.document import Document
    from bokeh.server.contexts import BokehSessionContext
    from bokeh.server.session import ServerSession
    from jinja2 import Template

    from ..template.base import BaseTemplate
    from ..viewable import Viewable, Viewer
    from .location import Location

    TViewable = Union[Viewable, Viewer, BaseTemplate]
    TViewableOrFunc = Union[TViewable, Callable[[], TViewable]]

# Private API

INDEX_HTML = os.path.join(os.path.dirname(__file__), '..', '_templates', "index.html")

def _origin_url(url: str) -> str:
    if url.startswith("http"):
        url = url.split("//")[1]
    return url

def _server_url(url: str, port: int) -> str:
    if url.startswith("http"):
        return '%s:%d%s' % (url.rsplit(':', 1)[0], port, "/")
        return 'http://%s:%d%s' % (url.split(':')[0], port, "/")

def _eval_panel(panel: 'TViewableOrFunc', server_id: str, title: str, location, doc: 'Document'):
    from ..template import BaseTemplate
    from ..pane import panel as as_panel

    with set_curdoc(doc):
        if isinstance(panel, (FunctionType, MethodType)):
            panel = panel()
        if isinstance(panel, BaseTemplate):
            doc = panel._modify_doc(server_id, title, doc, location)
            doc = as_panel(panel)._modify_doc(server_id, title, doc, location)
        return doc

[docs]def async_execute(func: Callable[..., None]) -> None: """ Wrap async event loop scheduling to ensure that with_lock flag is propagated from function to partial wrapping it. """ if not state.curdoc or not state.curdoc.session_context: ioloop = IOLoop.current() event_loop = ioloop.asyncio_loop # type: ignore if event_loop.is_running(): ioloop.add_callback(func) else: event_loop.run_until_complete(func()) return if isinstance(func, partial) and hasattr(func.func, 'lock'): unlock = not func.func.lock # type: ignore else: unlock = not getattr(func, 'lock', False) curdoc = state.curdoc @wraps(func) async def wrapper(*args, **kw): with set_curdoc(curdoc): return await func(*args, **kw) if unlock: wrapper.nolock = True # type: ignore state.curdoc.add_next_tick_callback(wrapper)
param.parameterized.async_executor = async_execute def _initialize_session_info(session_context: 'BokehSessionContext'): from ..config import config session_id = sessions = state.session_info['sessions'] history = -1 if config._admin else config.session_history if not config._admin and (history == 0 or session_id in sessions): return state.session_info['total'] += 1 if history > 0 and len(sessions) >= history: old_history = list(sessions.items()) sessions = OrderedDict(old_history[-(history-1):]) state.session_info['sessions'] = sessions sessions[session_id] = { 'launched':, 'started': None, 'rendered': None, 'ended': None, 'user_agent': session_context.request.headers.get('User-Agent') } state.param.trigger('session_info') state.on_session_created(_initialize_session_info) #--------------------------------------------------------------------- # Bokeh patches #--------------------------------------------------------------------- def server_html_page_for_session( session: 'ServerSession', resources: 'Resources', title: str, template: str | Template = BASE_TEMPLATE, template_variables: Optional[Dict[str, Any]] = None ) -> str: render_item = RenderItem( token = session.token, roots = session.document.roots, use_for_title = False, ) if template_variables is None: template_variables = {} bundle = bundle_resources(session.document.roots, resources) return html_page_for_render_items(bundle, {}, [render_item], title, template=template, template_variables=template_variables) def autoload_js_script(doc, resources, token, element_id, app_path, absolute_url): resources = Resources.from_bokeh(resources) bundle = bundle_resources(doc.roots, resources) render_items = [RenderItem(token=token, elementid=element_id, use_for_title=False)] bundle.add(Script(script_for_render_items({}, render_items, app_path=app_path, absolute_url=absolute_url))) return AUTOLOAD_JS.render(bundle=bundle, elementid=element_id)
[docs]def destroy_document(self, session): """ Override for Document.destroy() without calling gc.collect directly. The gc.collect() call is scheduled as a task, ensuring that when multiple documents are destroyed in quick succession we do not schedule excessive garbage collection. """ self.remove_on_change(session) del self._roots del self._theme del self._template self._session_context = None self.callbacks.destroy() self.models.destroy() self.modules.destroy() at = + dt.timedelta(seconds=5) state.schedule_task('gc.collect', gc.collect, at=at)
# Patch Application to handle session callbacks
[docs]class Application(BkApplication):
[docs] async def on_session_created(self, session_context): for cb in state._on_session_created: cb(session_context) await super().on_session_created(session_context)
[docs] def initialize_document(self, doc): super().initialize_document(doc) if doc in state._templates: template = state._templates[doc] template.server_doc(title=template.title, location=True, doc=doc)
bokeh.command.util.Application = Application # type: ignore class SessionPrefixHandler: @contextmanager def _session_prefix(self): prefix = self.request.uri.replace(self.application_context._url, '') if not prefix.endswith('/'): prefix += '/' base_url = urljoin('/', prefix) rel_path = '/'.join(['..'] * self.application_context._url.strip('/').count('/')) old_url, old_rel = state.base_url, state.rel_path # Handle autoload.js absolute paths abs_url = self.get_argument('bokeh-absolute-url', default=None) if abs_url is not None: app_path = self.get_argument('bokeh-app-path', default='') rel_path = abs_url.replace(app_path, '') with edit_readonly(state): state.base_url = base_url state.rel_path = rel_path try: yield finally: with edit_readonly(state): state.base_url = old_url state.rel_path = old_rel # Patch Bokeh DocHandler URL
[docs]class DocHandler(BkDocHandler, SessionPrefixHandler): @authenticated async def get(self, *args, **kwargs): with self._session_prefix(): session = await self.get_session() state.curdoc = session.document, id(session.document)) try: resources = Resources.from_bokeh(self.application.resources()) page = server_html_page_for_session( session, resources=resources, title=session.document.title, template=session.document.template, template_variables=session.document.template_variables ) finally: state.curdoc = None self.set_header("Content-Type", 'text/html') self.write(page)
per_app_patterns[0] = (r'/?', DocHandler) # Patch Bokeh Autoload handler
[docs]class AutoloadJsHandler(BkAutoloadJsHandler, SessionPrefixHandler): ''' Implements a custom Tornado handler for the autoload JS chunk ''' async def get(self, *args, **kwargs) -> None: element_id = self.get_argument("bokeh-autoload-element", default=None) if not element_id: self.send_error(status_code=400, reason='No bokeh-autoload-element query parameter') return app_path = self.get_argument("bokeh-app-path", default="/") absolute_url = self.get_argument("bokeh-absolute-url", default=None) if absolute_url: server_url = '{uri.scheme}://{uri.netloc}'.format(uri=urlparse(absolute_url)) else: server_url = None with self._session_prefix(): session = await self.get_session() state.curdoc = session.document try: resources = Resources.from_bokeh(self.application.resources(server_url)) js = autoload_js_script( session.document, resources, session.token, element_id, app_path, absolute_url ) finally: state.curdoc = None self.set_header("Content-Type", 'application/javascript') self.write(js)
per_app_patterns[3] = (r'/autoload.js', AutoloadJsHandler)
[docs]class ComponentResourceHandler(StaticFileHandler): """ A handler that serves local resources relative to a Python module. The handler resolves a specific Panel component by module reference and name, then resolves an attribute on that component to check if it contains the requested resource path. /<endpoint>/<module>/<class>/<attribute>/<path> """ _resource_attrs = [ '__css__', '__javascript__', '__js_module__', '_resources', '_css', '_js', 'base_css', 'css' ] def initialize(self, path: Optional[str] = None, default_filename: Optional[str] = None): self.root = path self.default_filename = default_filename
[docs] def parse_url_path(self, path: str) -> str: """ Resolves the resource the URL pattern refers to. """ parts = path.split('/') if len(parts) < 4: raise HTTPError(400, 'Malformed URL') mod, cls, rtype, *subpath = parts try: module = importlib.import_module(mod) except ModuleNotFoundError: raise HTTPError(404, 'Module not found') try: component = getattr(module, cls) except AttributeError: raise HTTPError(404, 'Component not found') # May only access resources listed in specific attributes if rtype not in self._resource_attrs: raise HTTPError(403, 'Requested resource type not valid.') try: resources = getattr(component, rtype) except AttributeError: raise HTTPError(404, 'Resource type not found') # Handle template resources if rtype == '_resources': rtype = subpath[0] subpath = subpath[1:] if rtype not in resources: raise HTTPError(404, 'Resource type not found') resources = resources[rtype] rtype = f'_resources/{rtype}' if isinstance(resources, dict): resources = list(resources.values()) elif isinstance(resources, (str, pathlib.PurePath)): resources = [resources] resources = [ component_rel_path(component, resource).replace(os.path.sep, '/') for resource in resources ] rel_path = '/'.join(subpath) # Important: May only access resources explicitly listed on the component # Otherwise this potentially exposes all files to the web if rel_path not in resources: raise HTTPError(403, 'Requested resource was not listed.') if not module.__file__: raise HTTPError(404, 'Requested module does not reference a file.') return str(pathlib.Path(module.__file__).parent / rel_path)
[docs] @classmethod def get_absolute_path(cls, root: str, path: str) -> str: return path
[docs] def validate_absolute_path(self, root: str, absolute_path: str) -> str: if not os.path.exists(absolute_path): raise HTTPError(404) if not os.path.isfile(absolute_path): raise HTTPError(403, "%s is not a file", self.path) return absolute_path
def modify_document(self, doc: 'Document'): from import set_curdoc as bk_set_curdoc from ..config import config, id(doc)) if config.autoreload: path = self._runner.path argv = self._runner._argv handler = type(self)(filename=path, argv=argv) self._runner = handler._runner module = self._runner.new_module() # If no module was returned it means the code runner has some permanent # unfixable problem, e.g. the configured source code has a syntax error if module is None: return # One reason modules are stored is to prevent the module # from being gc'd before the document is. A symptom of a # gc'd module is that its globals become None. Additionally # stored modules are used to provide correct paths to # custom models resolver. sys.modules[module.__name__] = module doc.modules._modules.append(module) try: old_doc = curdoc() except RuntimeError: old_doc = None bk_set_curdoc(doc) if config.autoreload: set_curdoc(doc) state.onload(autoreload_watcher) sessions = [] try: def post_check(): newdoc = curdoc() # Do not let curdoc track modules when autoreload is enabled # otherwise it will erroneously complain that there is # a memory leak if config.autoreload: newdoc.modules._modules = [] # script is supposed to edit the doc not replace it if newdoc is not doc: raise RuntimeError("%s at '%s' replaced the output document" % (self._origin, self._runner.path)) def handle_exception(handler, e): from bokeh.application.handlers.handler import handle_exception from ..pane import HTML # Clean up del sys.modules[module.__name__] if hasattr(doc, 'modules'): doc.modules._modules.remove(module) else: doc._modules.remove(module) bokeh.application.handlers.code_runner.handle_exception = handle_exception tb = html.escape(traceback.format_exc()) # Serve error HTML( f'<b>{type(e).__name__}</b>: {e}</br><pre style="overflow-y: scroll">{tb}</pre>', css_classes=['alert', 'alert-danger'], sizing_mode='stretch_width' ).servable() if config.autoreload: bokeh.application.handlers.code_runner.handle_exception = handle_exception state._launching.append(doc) with _monkeypatch_io(self._loggers): with patch_curdoc(doc): with profile_ctx(config.profiler) as sessions:, post_check) def _log_session_destroyed(session_context):, id(doc)) doc.on_session_destroyed(_log_session_destroyed) doc.destroy = partial(destroy_document, doc) # type: ignore finally: state._launching.remove(doc) if config.profiler: try: path = doc.session_context.request.path state._profiles[(path, config.profiler)] += sessions state.param.trigger('_profiles') except Exception: pass if old_doc is not None: bk_set_curdoc(old_doc) CodeHandler.modify_document = modify_document # type: ignore # Copied from bokeh 2.4.0, to fix directly in bokeh at some point. def create_static_handler(prefix, key, app): # patch key = '/__patchedroot' if key == '/' else key route = prefix route += "/static/(.*)" if key == "/" else key + "/static/(.*)" if app.static_path is not None: return (route, StaticFileHandler, {"path" : app.static_path}) return (route, StaticHandler, {}) bokeh.server.tornado.create_static_handler = create_static_handler # Bokeh 2.4.x patches the asyncio event loop policy but Tornado 6.1 # support the WindowsProactorEventLoopPolicy so we restore it, # unless we detect we are running on jupyter_server. if ( sys.platform == 'win32' and sys.version_info[:3] >= (3, 8, 0) and tornado.version_info >= (6, 1) and type(asyncio.get_event_loop_policy()) is asyncio.WindowsSelectorEventLoopPolicy and 'jupyter_server' not in sys.modules ): asyncio.set_event_loop_policy(asyncio.WindowsProactorEventLoopPolicy()) #--------------------------------------------------------------------- # Public API #---------------------------------------------------------------------
[docs]def serve( panels: 'TViewableOrFunc' | Mapping[str, 'TViewableOrFunc'], port: int = 0, address: Optional[str] = None, websocket_origin: Optional[str | list[str]] = None, loop: Optional[IOLoop] = None, show: bool = True, start: bool = True, title: Optional[str] = None, verbose: bool = True, location: bool = True, threaded: bool = False, **kwargs ) -> threading.Thread | 'Server': """ Allows serving one or more panel objects on a single server. The panels argument should be either a Panel object or a function returning a Panel object or a dictionary of these two. If a dictionary is supplied the keys represent the slugs at which each app is served, e.g. `serve({'app': panel1, 'app2': panel2})` will serve apps at /app and /app2 on the server. Reference: Arguments --------- panel: Viewable, function or {str: Viewable or function} A Panel object, a function returning a Panel object or a dictionary mapping from the URL slug to either. port: int (optional, default=0) Allows specifying a specific port address : str The address the server should listen on for HTTP requests. websocket_origin: str or list(str) (optional) A list of hosts that can connect to the websocket. This is typically required when embedding a server app in an external web site. If None, "localhost" is used. loop : tornado.ioloop.IOLoop (optional, default=IOLoop.current()) The tornado IOLoop to run the Server on show : boolean (optional, default=True) Whether to open the server in a new browser tab on start start : boolean(optional, default=True) Whether to start the Server title: str or {str: str} (optional, default=None) An HTML title for the application or a dictionary mapping from the URL slug to a customized title verbose: boolean (optional, default=True) Whether to print the address and port location : boolean or Whether to create a Location component to observe and set the URL location. threaded: boolean (default=False) Whether to start the server on a new Thread kwargs: dict Additional keyword arguments to pass to Server instance """ kwargs = dict(kwargs, **dict( port=port, address=address, websocket_origin=websocket_origin, loop=loop, show=show, start=start, title=title, verbose=verbose, location=location )) if threaded: kwargs['loop'] = loop = IOLoop() if loop is None else loop server = StoppableThread( target=get_server, io_loop=loop, args=(panels,), kwargs=kwargs ) server_id = kwargs.get('server_id', uuid.uuid4().hex) state._threads[server_id] = server server.start() else: return get_server(panels, **kwargs) return server
[docs]class ProxyFallbackHandler(RequestHandler): """A `RequestHandler` that wraps another HTTP server callback and proxies the subpath. """ def initialize(self, fallback, proxy=None): self.fallback = fallback self.proxy = proxy
[docs] def prepare(self): if self.proxy: self.request.path = self.request.path.replace(self.proxy, '') self.fallback(self.request) self._finished = True self.on_finish()
[docs]def get_static_routes(static_dirs): """ Returns a list of tornado routes of StaticFileHandlers given a dictionary of slugs and file paths to serve. """ patterns = [] for slug, path in static_dirs.items(): if not slug.startswith('/'): slug = '/' + slug if slug == '/static': raise ValueError("Static file route may not use /static " "this is reserved for internal use.") path = fullpath(path) if not os.path.isdir(path): raise ValueError("Cannot serve non-existent path %s" % path) patterns.append( (r"%s/(.*)" % slug, StaticFileHandler, {"path": path}) ) patterns.append(( f'/{COMPONENT_PATH}(.*)', ComponentResourceHandler, {} )) return patterns
[docs]def get_server( panel: 'TViewableOrFunc' | Mapping[str, 'TViewableOrFunc'], port: int = 0, address: Optional[str] = None, websocket_origin: Optional[str | list[str]] = None, loop: Optional[IOLoop] = None, show: bool = False, start: bool = False, title: bool = None, verbose: bool = False, location: bool | Location = True, static_dirs: Mapping[str, str] = {}, oauth_provider: Optional[str] = None, oauth_key: Optional[str] = None, oauth_secret: Optional[str] = None, oauth_extra_params: Mapping[str, str] = {}, cookie_secret: Optional[str] = None, oauth_encryption_key: Optional[str] = None, session_history: Optional[int] = None, **kwargs ) -> Server: """ Returns a Server instance with this panel attached as the root app. Arguments --------- panel: Viewable, function or {str: Viewable} A Panel object, a function returning a Panel object or a dictionary mapping from the URL slug to either. port: int (optional, default=0) Allows specifying a specific port address : str The address the server should listen on for HTTP requests. websocket_origin: str or list(str) (optional) A list of hosts that can connect to the websocket. This is typically required when embedding a server app in an external web site. If None, "localhost" is used. loop : tornado.ioloop.IOLoop (optional, default=IOLoop.current()) The tornado IOLoop to run the Server on. show : boolean (optional, default=False) Whether to open the server in a new browser tab on start. start : boolean(optional, default=False) Whether to start the Server. title : str or {str: str} (optional, default=None) An HTML title for the application or a dictionary mapping from the URL slug to a customized title. verbose: boolean (optional, default=False) Whether to report the address and port. location : boolean or Whether to create a Location component to observe and set the URL location. static_dirs: dict (optional, default={}) A dictionary of routes and local paths to serve as static file directories on those routes. oauth_provider: str One of the available OAuth providers oauth_key: str (optional, default=None) The public OAuth identifier oauth_secret: str (optional, default=None) The client secret for the OAuth provider oauth_extra_params: dict (optional, default={}) Additional information for the OAuth provider cookie_secret: str (optional, default=None) A random secret string to sign cookies (required for OAuth) oauth_encryption_key: str (optional, default=False) A random encryption key used for encrypting OAuth user information and access tokens. session_history: int (optional, default=None) The amount of session history to accumulate. If set to non-zero and non-None value will launch a REST endpoint at /rest/session_info, which returns information about the session history. kwargs: dict Additional keyword arguments to pass to Server instance. Returns ------- server : bokeh.server.server.Server Bokeh Server instance running this panel """ from ..config import config from .rest import REST_PROVIDERS server_id = kwargs.pop('server_id', uuid.uuid4().hex) kwargs['extra_patterns'] = extra_patterns = kwargs.get('extra_patterns', []) if isinstance(panel, dict): apps = {} for slug, app in panel.items(): if isinstance(title, dict): try: title_ = title[slug] except KeyError: raise KeyError( "Keys of the title dictionnary and of the apps " f"dictionary must match. No {slug} key found in the " "title dictionary.") else: title_ = title slug = slug if slug.startswith('/') else '/'+slug if 'flask' in sys.modules: from flask import Flask if isinstance(app, Flask): wsgi = WSGIContainer(app) if slug == '/': raise ValueError('Flask apps must be served on a subpath.') if not slug.endswith('/'): slug += '/' extra_patterns.append(('^'+slug+'.*', ProxyFallbackHandler, dict(fallback=wsgi, proxy=slug))) continue if isinstance(app, pathlib.Path): app = str(app) # enables serving apps from Paths if (isinstance(app, str) and (app.endswith(".py") or app.endswith(".ipynb")) and os.path.isfile(app)): apps[slug] = build_single_handler_application(app) elif isinstance(app, Application): apps[slug] = app else: handler = FunctionHandler(partial(_eval_panel, app, server_id, title_, location)) apps[slug] = Application(handler) else: handler = FunctionHandler(partial(_eval_panel, panel, server_id, title, location)) apps = {'/': Application(handler)} extra_patterns += get_static_routes(static_dirs) if session_history is not None: config.session_history = session_history if config.session_history != 0: pattern = REST_PROVIDERS['param']([], 'rest') extra_patterns.extend(pattern) state.publish('session_info', state, ['session_info']) opts = dict(kwargs) if loop: loop.make_current() opts['io_loop'] = loop elif opts.get('num_procs', 1) == 1: opts['io_loop'] = IOLoop.current() if 'index' not in opts: opts['index'] = INDEX_HTML if address is not None: opts['address'] = address if websocket_origin: if not isinstance(websocket_origin, list): websocket_origin = [websocket_origin] opts['allow_websocket_origin'] = websocket_origin # Configure OAuth from ..config import config if oauth_provider: from ..auth import OAuthProvider config.oauth_provider = oauth_provider # type: ignore opts['auth_provider'] = OAuthProvider() if oauth_key: config.oauth_key = oauth_key # type: ignore if oauth_extra_params: config.oauth_extra_params = oauth_extra_params # type: ignore if cookie_secret: config.cookie_secret = cookie_secret # type: ignore opts['cookie_secret'] = config.cookie_secret server = Server(apps, port=port, **opts) if verbose: address = server.address or 'localhost' url = f"http://{address}:{server.port}{server.prefix}" print(f"Launching server at {url}") state._servers[server_id] = (server, panel, []) if show: def show_callback():'/login' if config.oauth_provider else '/') server.io_loop.add_callback(show_callback) def sig_exit(*args, **kwargs): server.io_loop.add_callback_from_signal(do_stop) def do_stop(*args, **kwargs): server.io_loop.stop() try: signal.signal(signal.SIGINT, sig_exit) except ValueError: pass # Can't use signal on a thread if start: server.start() try: server.io_loop.start() except RuntimeError: pass except TypeError: warnings.warn( "IOLoop couldn't be started. Ensure it is started by " "process invoking the" ) return server
[docs]class StoppableThread(threading.Thread): """Thread class with a stop() method.""" def __init__(self, io_loop: IOLoop, **kwargs): super().__init__(**kwargs) self.io_loop = io_loop
[docs] def run(self) -> None: if hasattr(self, '_target'): target, args, kwargs = self._target, self._args, self._kwargs # type: ignore else: target, args, kwargs = self._Thread__target, self._Thread__args, self._Thread__kwargs # type: ignore if not target: return bokeh_server = None try: bokeh_server = target(*args, **kwargs) finally: if isinstance(bokeh_server, Server): try: bokeh_server.stop() except Exception: pass if hasattr(self, '_target'): del self._target, self._args, self._kwargs # type: ignore else: del self._Thread__target, self._Thread__args, self._Thread__kwargs # type: ignore
def stop(self) -> None: self.io_loop.add_callback(self.io_loop.stop)