"""
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 threading
import traceback
import uuid
import weakref
from collections import OrderedDict
from contextlib import contextmanager
from functools import partial, wraps
from html import escape
from types import FunctionType, MethodType
from typing import (
TYPE_CHECKING, Any, Callable, Dict, Mapping, Optional, Union,
)
from urllib.parse import urljoin, urlparse
import bokeh
import bokeh.command.util
import param
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.core.json_encoder import serialize_json
from bokeh.core.templates import AUTOLOAD_JS, FILE, MACROS
from bokeh.core.validation import silence
from bokeh.core.validation.warnings import EMPTY_LAYOUT
from bokeh.embed.bundle import Script
from bokeh.embed.elements import script_for_render_items
from bokeh.embed.util import RenderItem
from bokeh.embed.wrappers import wrap_in_script_tag
from bokeh.io import curdoc
from bokeh.models import CustomJS
from bokeh.server.server import Server as BokehServer
from bokeh.server.urls import per_app_patterns, toplevel_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.root_handler import RootHandler as BkRootHandler
from bokeh.server.views.static_handler import StaticHandler
from bokeh.util.serialization import make_id
from bokeh.util.token import (
generate_jwt_token, generate_session_id, get_token_payload,
)
# Tornado imports
from tornado.ioloop import IOLoop
from tornado.web import (
HTTPError, RequestHandler, StaticFileHandler, authenticated,
)
from tornado.wsgi import WSGIContainer
# Internal imports
from ..config import config
from ..util import edit_readonly, fullpath
from ..util.warnings import warn
from .document import init_doc, unlocked, with_lock # noqa
from .loading import LOADING_INDICATOR_CSS_CLASS
from .logging import (
LOG_SESSION_CREATED, LOG_SESSION_DESTROYED, LOG_SESSION_LAUNCHING,
)
from .markdown import build_single_handler_application
from .profile import profile_ctx
from .reload import autoreload_watcher
from .resources import (
BASE_TEMPLATE, CDN_DIST, COMPONENT_PATH, ERROR_TEMPLATE, LOCAL_DIST,
Resources, _env, bundle_resources, patch_model_css, resolve_custom_path,
)
from .state import set_curdoc, state
logger = logging.getLogger(__name__)
if TYPE_CHECKING:
from bokeh.bundle import Bundle
from bokeh.core.types import ID
from bokeh.document.document import DocJson, 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]
TViewableFuncOrPath = Union[TViewable, Callable[[], TViewable], os.PathLike, str]
#---------------------------------------------------------------------
# Private API
#---------------------------------------------------------------------
INDEX_HTML = os.path.join(os.path.dirname(__file__), '..', '_templates', "index.html")
DEFAULT_TITLE = "Panel Application"
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, "/")
else:
return 'http://%s:%d%s' % (url.split(':')[0], port, "/")
def _eval_panel(
panel: TViewableFuncOrPath, server_id: str, title: str,
location: bool | Location, admin: bool, doc: Document
):
from ..pane import panel as as_panel
from ..template import BaseTemplate
if config.global_loading_spinner:
doc.js_on_event(
'document_ready', CustomJS(code=f"""
const body = document.getElementsByTagName('body')[0]
body.classList.remove({LOADING_INDICATOR_CSS_CLASS!r}, {config.loading_spinner!r})
""")
)
# Set up instrumentation for logging sessions
logger.info(LOG_SESSION_LAUNCHING, id(doc))
def _log_session_destroyed(session_context):
logger.info(LOG_SESSION_DESTROYED, id(doc))
doc.on_session_destroyed(_log_session_destroyed)
with set_curdoc(doc):
if isinstance(panel, (FunctionType, MethodType)):
panel = panel()
if isinstance(panel, BaseTemplate):
doc = panel._modify_doc(server_id, title, doc, location)
else:
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
wrapper = state._handle_exception_wrapper(func)
if event_loop.is_running():
ioloop.add_callback(wrapper)
else:
event_loop.run_until_complete(wrapper())
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):
try:
return await func(*args, **kw)
except Exception as e:
state._handle_exception(e)
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 = session_context.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': dt.datetime.now().timestamp(),
'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
#---------------------------------------------------------------------
[docs]def html_page_for_render_items(
bundle: Bundle | tuple[str, str], docs_json: dict[ID, DocJson],
render_items: list[RenderItem], title: str, template: Template | str | None = None,
template_variables: dict[str, Any] = {}
) -> str:
"""
Render an HTML page from a template and Bokeh render items.
Arguments
---------
bundle (tuple):
A tuple containing (bokehjs, bokehcss)
docs_json (JSON-like):
Serialized Bokeh Document
render_items (RenderItems)
Specific items to render from the document and where
title (str or None)
A title for the HTML page. If None, DEFAULT_TITLE is used
template (str or Template or None, optional) :
A Template to be used for the HTML page. If None, FILE is used.
template_variables (dict, optional):
Any Additional variables to pass to the template
Returns
-------
str
"""
if title is None:
title = DEFAULT_TITLE
bokeh_js, bokeh_css = bundle
json_id = make_id()
json = escape(serialize_json(docs_json), quote=False)
json = wrap_in_script_tag(json, "application/json", json_id)
script = wrap_in_script_tag(script_for_render_items(json_id, render_items))
context = template_variables.copy()
context.update(dict(
title = title,
bokeh_js = bokeh_js,
bokeh_css = bokeh_css,
plot_script = json + script,
docs = render_items,
base = BASE_TEMPLATE,
macros = MACROS,
))
if len(render_items) == 1:
context["doc"] = context["docs"][0]
context["roots"] = context["doc"].roots
if template is None:
template = BASE_TEMPLATE
elif isinstance(template, str):
template = _env.from_string("{% extends base %}\n" + template)
html = template.render(context)
return html
def server_html_page_for_session(
session: 'ServerSession',
resources: 'Resources',
title: str,
token: str | None = None,
template: str | Template = BASE_TEMPLATE,
template_variables: Optional[Dict[str, Any]] = None,
) -> str:
# ALERT: Replace with better approach before Bokeh 3.x compatible release
if resources.mode == 'server':
dist_url = f'{state.rel_path}/{LOCAL_DIST}' if state.rel_path else LOCAL_DIST
else:
dist_url = CDN_DIST
doc = session.document
doc._template_variables['theme_name'] = config.theme
doc._template_variables['dist_url'] = dist_url
for root in doc.roots:
patch_model_css(root, dist_url=dist_url)
render_item = RenderItem(
token = token or session.token,
roots = doc.roots,
use_for_title = False,
)
if template_variables is None:
template_variables = {}
if template is FILE:
template = BASE_TEMPLATE
with set_curdoc(doc):
bundle = bundle_resources(doc.roots, resources)
html = html_page_for_render_items(
bundle, {}, [render_item], title, template=template,
template_variables=template_variables
)
if config.global_loading_spinner:
html = html.replace(
'<body>', f'<body class="{LOADING_INDICATOR_CSS_CLASS} pn-{config.loading_spinner}">'
)
return html
def autoload_js_script(doc, resources, token, element_id, app_path, absolute_url, absolute=False):
resources = Resources.from_bokeh(resources, absolute=absolute)
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.
"""
if session is not None:
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()
# Clear periodic callbacks
for cb in state._periodic.get(self, []):
cb.stop()
# Clean up pn.state to avoid tasks getting executed on dead session
for attr in dir(state):
if not attr.startswith('_'):
continue
state_obj = getattr(state, attr)
if isinstance(state_obj, weakref.WeakKeyDictionary) and self in state_obj:
del state_obj[self]
# Schedule GC
at = dt.datetime.now() + dt.timedelta(seconds=5)
state.schedule_task('gc.collect', gc.collect, at=at)
del self.destroy
# Patch Server to attach task factory to asyncio loop and handle Admin server context
[docs]class Server(BokehServer):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
if state._admin_context:
state._admin_context._loop = self._loop
[docs] def start(self) -> None:
super().start()
if state._admin_context:
self._loop.add_callback(state._admin_context.run_load_hook)
[docs] def stop(self, wait: bool = True) -> None:
super().stop(wait=wait)
if state._admin_context:
state._admin_context.run_unload_hook()
bokeh.server.server.Server = Server
# Patch Application to handle session callbacks
[docs]class Application(BkApplication):
def __init__(self, *args, **kwargs):
self._admin = kwargs.pop('admin', None)
super().__init__(*args, **kwargs)
[docs] async def on_session_created(self, session_context):
with set_curdoc(session_context._document):
if self._admin is not None:
config._admin = self._admin
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 and doc not in state._templates[doc]._documents:
template = state._templates[doc]
with set_curdoc(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:
rel_path = abs_url.replace(self.application_context._url, '')
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_session(self):
from ..config import config
path = self.request.path
session = None
if config.reuse_sessions and path in state._session_key_funcs:
key = state._session_key_funcs[path](self.request)
session = state._sessions.get(key)
if session is None:
session = await super().get_session()
with set_curdoc(session.document):
if config.reuse_sessions:
key_func = config.session_key_func or (lambda r: (r.path, r.arguments.get('theme', [b'default'])[0].decode('utf-8')))
state._session_key_funcs[path] = key_func
key = key_func(self.request)
state._sessions[key] = session
session.block_expiration()
return session
@authenticated
async def get(self, *args, **kwargs):
app = self.application
with self._session_prefix():
key_func = state._session_key_funcs.get(self.request.path, lambda r: r.path)
old_request = key_func(self.request) in state._sessions
session = await self.get_session()
if old_request and state._sessions.get(key_func(self.request)) is session:
session_id = generate_session_id(
secret_key=self.application.secret_key,
signed=self.application.sign_sessions
)
payload = get_token_payload(session.token)
del payload['session_expiry']
token = generate_jwt_token(
session_id,
secret_key=app.secret_key,
signed=app.sign_sessions,
expiration=app.session_token_expiration,
extra_payload=payload
)
else:
token = session.token
logger.info(LOG_SESSION_CREATED, id(session.document))
with set_curdoc(session.document):
if config.authorize_callback and not config.authorize_callback(state.user_info):
if config.auth_template:
with open(config.auth_template) as f:
template = _env.from_string(f.read())
else:
template = ERROR_TEMPLATE
page = template.render(
npm_cdn=config.npm_cdn,
title='Panel: Authorization Error',
error_type='Authorization Error',
error='User is not authorized.',
error_msg=f'{state.user} is not authorized to access this application.'
)
else:
resources = Resources.from_bokeh(self.application.resources())
page = server_html_page_for_session(
session, resources=resources, title=session.document.title,
token=token, template=session.document.template,
template_variables=session.document.template_variables,
)
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()
with set_curdoc(session.document):
resources = Resources.from_bokeh(
self.application.resources(server_url), absolute=True
)
js = autoload_js_script(
session.document, resources, session.token, element_id,
app_path, absolute_url, absolute=True
)
self.set_header("Content-Type", 'application/javascript')
self.write(js)
per_app_patterns[3] = (r'/autoload.js', AutoloadJsHandler)
[docs]class RootHandler(BkRootHandler):
"""
Custom RootHandler that provides the CDN_DIST directory as a
template variable.
"""
[docs] def render(self, *args, **kwargs):
kwargs['PANEL_CDN'] = CDN_DIST
return super().render(*args, **kwargs)
toplevel_patterns[0] = (r'/?', RootHandler)
bokeh.server.tornado.RootHandler = RootHandler
[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__', '__javascript_modules__', '_resources',
'_css', '_js', 'base_css', 'css', '_stylesheets', 'modifiers'
]
[docs] 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}'
elif rtype == 'modifiers':
resources = [
st for rs in resources.values() for st in rs.get('stylesheets', [])
if isinstance(st, str)
]
if isinstance(resources, dict):
resources = list(resources.values())
elif isinstance(resources, (str, pathlib.PurePath)):
resources = [resources]
resources = [
str(resolve_custom_path(component, resource, relative=True)).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 bokeh.io.doc import set_curdoc as bk_set_curdoc
from ..config import config
logger.info(LOG_SESSION_LAUNCHING, 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 Alert
# 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()).replace('\033[1m', '<b>').replace('\033[0m', '</b>')
# Serve error
e_msg = str(e).replace('\033[1m', '<b>').replace('\033[0m', '</b>')
Alert(
f'<b>{type(e).__name__}</b>: {e_msg}\n<pre style="overflow-y: auto">{tb}</pre>',
alert_type='danger', margin=5, 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:
self._runner.run(module, post_check)
def _log_session_destroyed(session_context):
logger.info(LOG_SESSION_DESTROYED, 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
#---------------------------------------------------------------------
# Async patches
#---------------------------------------------------------------------
# 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 and
'jupyter_client' not in sys.modules) or
'pytest' in sys.modules)
):
asyncio.set_event_loop_policy(asyncio.WindowsProactorEventLoopPolicy())
#---------------------------------------------------------------------
# Public API
#---------------------------------------------------------------------
[docs]def serve(
panels: TViewableFuncOrPath | Mapping[str, TViewableFuncOrPath],
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,
admin: 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: https://panel.holoviz.org/user_guide/Server_Configuration.html#serving-multiple-apps
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 panel.io.location.Location
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
admin: boolean (default=False)
Whether to enable the admin panel
kwargs: dict
Additional keyword arguments to pass to Server instance
"""
# Empty layout are valid and the Bokeh warning is silenced as usually
# not relevant to Panel users.
silence(EMPTY_LAYOUT, True)
kwargs = dict(kwargs, **dict(
port=port, address=address, websocket_origin=websocket_origin,
loop=loop, show=show, start=start, title=title, verbose=verbose,
location=location, admin=admin
))
if threaded:
kwargs['loop'] = loop = IOLoop(make_current=False) 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.
"""
[docs] 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: TViewableFuncOrPath | Mapping[str, TViewableFuncOrPath],
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,
admin: bool = False,
static_dirs: Mapping[str, str] = {},
basic_auth: str = None,
oauth_provider: Optional[str] = None,
oauth_key: Optional[str] = None,
oauth_secret: Optional[str] = None,
oauth_redirect_uri: 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 panel.io.location.Location
Whether to create a Location component to observe and
set the URL location.
admin: boolean (default=False)
Whether to enable the admin panel
static_dirs: dict (optional, default={})
A dictionary of routes and local paths to serve as static file
directories on those routes.
basic_auth: str (optional, default=None)
Password or filepath to use with basic auth provider.
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_redirect_uri: Optional[str] = None,
Overrides the default OAuth redirect URI
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 : panel.io.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 dictionary 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") or app.endswith('.md'))
and os.path.isfile(app)):
apps[slug] = app = build_single_handler_application(app)
app._admin = admin
elif isinstance(app, BkApplication):
apps[slug] = app
else:
handler = FunctionHandler(partial(_eval_panel, app, server_id, title_, location, admin))
apps[slug] = Application(handler, admin=admin)
else:
if isinstance(panel, pathlib.Path):
panel = str(panel) # enables serving apps from Paths
if (isinstance(panel, str) and (panel.endswith(".py") or panel.endswith(".ipynb") or panel.endswith('.md'))
and os.path.isfile(panel)):
apps = {'/': build_single_handler_application(panel)}
else:
handler = FunctionHandler(partial(_eval_panel, panel, server_id, title, location, admin))
apps = {'/': Application(handler, admin=admin)}
if admin:
if '/admin' in apps:
raise ValueError(
'Cannot enable admin panel because another app is being served '
'on the /admin endpoint'
)
from .admin import admin_panel
admin_handler = FunctionHandler(admin_panel)
apps['/admin'] = Application(admin_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:
asyncio.set_event_loop(loop.asyncio_loop)
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
server_config = {}
if basic_auth:
from ..auth import BasicProvider
server_config['basic_auth'] = basic_auth
opts['auth_provider'] = BasicProvider()
elif 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_secret:
config.oauth_secret = oauth_secret # 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
if oauth_redirect_uri:
config.oauth_redirect_uri = oauth_redirect_uri # 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, [])
state._server_config[server._tornado] = server_config
if show:
def show_callback():
server.show('/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:
warn(
"IOLoop couldn't be started. Ensure it is started by "
"process invoking the panel.io.server.serve."
)
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)
