#----------------------------------------------------------------------------- # Copyright (c) 2012 - 2019, Anaconda, Inc., and Bokeh Contributors. # All rights reserved. # # The full license is in the file LICENSE.txt, distributed with this software. #----------------------------------------------------------------------------- ''' Control global configuration options with environment variables. A global settings object that other parts of Bokeh can refer to. Defined Settings ~~~~~~~~~~~~~~~~ Settings are accessible on the ``bokeh.settings.settings`` instance, via accessor methods. For instance: .. code-block:: python settings.minified() Bokeh provides the following defined settings: .. bokeh-settings:: settings :module: bokeh.settings Precedence ~~~~~~~~~~ Setting values are always looked up in the following prescribed order: immediately supplied values These are values that are passed to the setting: .. code-block:: python settings.minified(minified_val) If ``minified_val`` is not None, then it will be returned, as-is. Otherwise, if None is passed, then the setting will continute to look down the search order for a value. This is useful for passing optional function paramters that are None by default. If the parameter is passed to the function, then it will take precedence. previously user-set values If the value is set explicity in code: .. code-block:: python settings.minified = False Then this value will take precedence over other sources. Applications may use this ability to set values supplied on the command line, so that they take precedence over environment variables. user-specified config override file Values from a YAML configuration file that is explicitly loaded: .. code-block:: python settings.load_config("/path/to/bokeh.yaml) Any values from ``bokeh.yaml`` will take precedence over the sources below. Applications may offer command line arguments to load such a file. e.g. ``bokeh serve --use-config myconf.yaml`` environment variable Values found in the associated environment variables: .. code-block:: sh BOKEH_MINIFIED=no bokeh serve app.py local user config file Bokeh will look for a YAML configuration file in the current user's home directory ``${HOME}/.bokeh/bokeh.yaml``. global system configuration (not yet implemented) Future support is planned to load Bokeh settings from global system configurations. implicit defaults These are default values defined by the setting declarations. There are regular defaults, as well as "dev" defaults that are used when the environment variable ``BOKEH_DEV=yes`` is set. If no value is obtained after searching all of these locations, then a RuntimeError will be raised. API ~~~ There are a few methods on the ``settings`` object: .. autoclass:: Settings :members: ''' #----------------------------------------------------------------------------- # Boilerplate #----------------------------------------------------------------------------- from __future__ import absolute_import, division, print_function, unicode_literals import logging log = logging.getLogger(__name__) #----------------------------------------------------------------------------- # Imports #----------------------------------------------------------------------------- # Standard library imports import codecs import os from os.path import abspath, expanduser, join # External imports import yaml # Bokeh imports from .util.paths import bokehjsdir #----------------------------------------------------------------------------- # Globals and constants #----------------------------------------------------------------------------- __all__ = ( 'settings', ) #----------------------------------------------------------------------------- # General API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Dev API #----------------------------------------------------------------------------- def convert_str(value): ''' Return a string as-is ''' return value def convert_bool(value): ''' Convert a string to True or False If a boolean is passed in, it is returned as-is. Otherwise the function maps the following strings, ignoring case: * "yes", "1", "on" -> True * "no", "0", "off" -> False Args: value (str): A string value to convert to bool Returns: bool Raises: ValueError ''' if value in (True, False): return value val = value.lower() if val in ["yes", "1", "on", "true", "True"]: return True if val in ["no", "0", "off", "false", "False"]: return False raise ValueError("Cannot convert {} to boolean value".format(value)) def convert_str_seq(value): ''' Convert a string to a lit of strings If a list or tuple is passed in, it is returned as-is. Args: value (str) : A string to convert to a list of strings Returns list[str] ''' if isinstance(value, (list, tuple)): return value try: return value.split(",") except: raise ValueError("Cannot convert {} to list value".format(value)) _log_levels = { "CRITICAL" : logging.CRITICAL, "ERROR" : logging.ERROR, "WARNING" : logging.WARNING, "INFO" : logging.INFO, "DEBUG" : logging.DEBUG, "TRACE" : 9, # Custom level hard-coded to avoid circular import "NONE" : None, } def convert_logging(value): '''Convert a string to a Python logging level If a log level is passed in, it is returned as-is. Otherwise the function understands the following strings, ignoring case: * "critical" * "error" * "warning" * "info" * "debug" * "trace" * "none" Args: value (str): A string value to convert to a logging level Returns: int or None Raises: ValueError ''' if value in set(_log_levels.values()): return value value = value.upper() if value in _log_levels: return _log_levels[value] raise ValueError("Cannot convert {} to log level, valid values are: {}".format(value, ", ".join(_log_levels))) class _Unset: pass def is_dev(): return convert_bool(os.environ.get("BOKEH_DEV", False)) class PrioritizedSetting(object): ''' Return a value for a global setting according to configuration precedence. The following methods are searched in order for the setting: 6. immediately supplied values 5. previously user-set values (e.g. set from command line) 4. user-specified config override file 3. environment variable 2. local user config file 1. global system config file (not yet implemented) 0. implicit defaults Ref: https://stackoverflow.com/a/11077282/3406693 If a value cannot be determined, a ValueError is raised. The ``env_var`` argument specifies the name of an environment to check for setting values, e.g. ``"BOKEH_LOG_LEVEL"``. The optional ``default`` argument specified an implicit default value for the setting that is returned if no other methods provide a value. A ``convert`` agument may be provided to convert values before they are returned. For instance to concert log levels in environment variables to ``logging`` module values. ''' def __init__(self, name, env_var=None, default=_Unset, dev_default=_Unset, convert=None, help=""): self._convert = convert if convert else convert_str self._default = default self._dev_default = dev_default self._env_var = env_var self._help = help self._name = name self._parent = None self._user_value = _Unset def __call__(self, value=None): '''Return the setting value according to the standard precedence. Args: value (any, optional): An optional immediate value. If not None, the value will be converted, then returned. Returns: str or int or float Raises: RuntimeError ''' # 6. immediate values if value is not None: return self._convert(value) # 5. previously user-set value if self._user_value is not _Unset: return self._convert(self._user_value) # 4. user-named config file if self._parent and self._name in self._parent.config_override: return self._convert(self._parent.config_override[self._name]) # 3. environment variable if self._env_var and self._env_var in os.environ: return self._convert(os.environ[self._env_var]) # 2. local config file if self._parent and self._name in self._parent.config_user: return self._convert(self._parent.config_user[self._name]) # 1. global config file if self._parent and self._name in self._parent.config_system: return self._convert(self._parent.config_system[self._name]) # 0. implicit defaults if is_dev() and self._dev_default is not _Unset: return self._convert(self._dev_default) if self._default is not _Unset: return self._convert(self._default) raise RuntimeError("No configured value found for setting %r" % self._name) def __get__(self, instance, owner): return self def __set__(self, instance, value): self.set_value(value) def set_value(self, value): ''' Specify a value for this setting programmatically. A value set this way takes precedence over all other methods except immediate values. Args: value (str or int or float): A user-set value for this setting Returns: None ''' self._user_value = value def unset_value(self): ''' Unset the previous user value such that the priority is reset. ''' self._user_value = _Unset @property def env_var(self): return self._env_var @property def default(self): return self._default @property def dev_default(self): return self._dev_default @property def name(self): return self._name @property def help(self): return self._help @property def convert_type(self): if self._convert is convert_str: return "String" if self._convert is convert_bool: return "Bool" if self._convert is convert_logging: return "Log Level" if self._convert is convert_str_seq: return "List[String]" _config_user_locations = ( join(expanduser("~"), ".bokeh", "bokeh.yaml"), ) _config_system_locations = () [docs]class Settings(object): ''' ''' def __init__(self): self._config_override = {} self._config_user = self._try_load_config(_config_user_locations) self._config_system = {} # TODO (bev) for x in self.__class__.__dict__.values(): if isinstance(x, PrioritizedSetting): x._parent = self @property def config_system(self): return dict(self._config_system) @property def config_user(self): return dict(self._config_user) @property def config_override(self): return dict(self._config_override) @property def dev(self): return is_dev() allowed_ws_origin = PrioritizedSetting("allowed_ws_origin", "BOKEH_ALLOW_WS_ORIGIN", default=[], convert=convert_str_seq, help=""" A comma-separated list of allowed websocket origins for Bokeh server applications. """) auth_module = PrioritizedSetting("auth_module", "BOKEH_AUTH_MODULE", default=None, help=""" A path to a Python modules that implements user authentication functions for the Bokeh server. .. warning:: The contents of this module will be executed! """) browser = PrioritizedSetting("browser", "BOKEH_BROWSER", default=None, dev_default="none", help=""" The default browser that Bokeh should use to show documents with. Valid values are any of the browser names understood by the python standard library webbrowser_ module. .. _webbrowser: https://docs.python.org/2/library/webbrowser.html """) cookie_secret = PrioritizedSetting("cookie_secret", "BOKEH_COOKIE_SECRET", default=None, help=""" Configure the ``cookie_secret`` setting in Tornado. This value is required if you use ``get_secure_cookie`` or ``set_secure_cookie``. It should be a long, random sequence of bytes """) docs_cdn = PrioritizedSetting("docs_cdn", "BOKEH_DOCS_CDN", default=None, help=""" The version of BokehJS that should be use for loading CDN resources when building the docs. To build and display the docs using a locally built BokehJS, use ``local``. For example: .. code-block:: sh BOKEH_DOCS_CDN=local make clean serve Will build a fresh copy of the docs using the locally built BokehJS and open a new browser tab to view them. Otherwise, the value is interpreted a version for CDN. For example: .. code-block:: sh BOKEH_DOCS_CDN=1.4.0rc1 make clean will build docs that use BokehJS version ``1.4.0rc1`` from CDN. """) docs_version = PrioritizedSetting("docs_version", "BOKEH_DOCS_VERSION", default=None, help=""" The Bokeh version to stipulate when building the docs. This setting is necessary to re-deploy existing versions of docs with new fixes or changes. """) ignore_filename = PrioritizedSetting("ignore_filename", "BOKEH_IGNORE_FILENAME", default=False, convert=convert_bool, help=""" Whether to ignore the current script filename when saving Bokeh content. """) log_level = PrioritizedSetting("log_level", "BOKEH_LOG_LEVEL", default="info", dev_default="debug", help=""" Set the log level for JavaScript BokehJS code. Valid values are, in order of increasing severity: - ``trace`` - ``debug`` - ``info`` - ``warn`` - ``error`` - ``fatal`` """) minified = PrioritizedSetting("minified", "BOKEH_MINIFIED", convert=convert_bool, default=True, dev_default=False, help=""" Whether Bokeh should use minified BokehJS resources. """) nodejs_path = PrioritizedSetting("nodejs_path", "BOKEH_NODEJS_PATH", default=None, help=""" Path to the Node executable. NodeJS is an optional dependency that is required for PNG and SVG export, and for compiling custom extensions. Bokeh will try to automatically locate an installed Node executable. Use this environment variable to override the location Bokeh finds, or to point to a non-standard location. """) perform_document_validation = PrioritizedSetting("validate_doc", "BOKEH_VALIDATE_DOC", convert=convert_bool, default=True, help=""" whether Bokeh should perform validation checks on documents. Setting this value to False may afford a small performance improvement. """) phantomjs_path = PrioritizedSetting("phantomjs_path", "BOKEH_PHANTOMJS_PATH", default=None, help=""" Path to the PhantomJS executable. PhantomJS is an optional dependency that is required for PNG and SVG export. Bokeh will try to automatically locate an installed PhantomJS executable. Use this environment variable to override the location Bokeh finds, or to point to a non-standard location. """) pretty = PrioritizedSetting("pretty", "BOKEH_PRETTY", default=False, dev_default=True, help=""" Whether JSON strings should be pretty-printed. """) py_log_level = PrioritizedSetting("py_log_level", "BOKEH_PY_LOG_LEVEL", default="none", dev_default="debug", convert=convert_logging, help=""" The log level for Python Bokeh code. Valid values are, in order of increasing severity: - ``trace`` - ``debug`` - ``info`` - ``warn`` - ``error`` - ``fatal`` - ``none`` """) resources = PrioritizedSetting("resources", "BOKEH_RESOURCES", default="cdn", dev_default="absolute-dev", help=""" What kind of BokehJS resources to configure, e.g ``inline`` or ``cdn`` See the :class:`~bokeh.resources.Resources` class reference for full details. """) rootdir = PrioritizedSetting("rootdir", "BOKEH_ROOTDIR", default=None, help=""" Root directory to use with ``relative`` resources See the :class:`~bokeh.resources.Resources` class reference for full details. """) secret_key = PrioritizedSetting("secret_key", "BOKEH_SECRET_KEY", default=None, help=""" A long, cryptographically-random secret unique to a Bokeh deployment. """) sign_sessions = PrioritizedSetting("sign_sessions", "BOKEH_SIGN_SESSIONS", default=False, help=""" Whether the Boeh server should only allow sessions signed with a secret key. If True, ``BOKEH_SECRET_KEY`` must also be set. """) simple_ids = PrioritizedSetting("simple_ids", "BOKEH_SIMPLE_IDS", default=True, convert=convert_bool, help=""" Whether Bokeh should use simple integers for model IDs (starting at 1000). If False, Bokeh will use UUIDs for object identifiers. This might be needed, e.g., if mulitple processes are contributing to a single Bokeh Document. """) ssl_certfile = PrioritizedSetting("ssl_certfile", "BOKEH_SSL_CERTFILE", default=None, help=""" The path to a certificate file for SSL termination. """) ssl_keyfile = PrioritizedSetting("ssl_keyfile", "BOKEH_SSL_KEYFILE", default=None, help=""" The path to a private key file for SSL termination. """) ssl_password = PrioritizedSetting("ssl_password", "BOKEH_SSL_PASSWORD", default=None, help=""" A password to decrypt the SSL keyfile, if necessary. """) strict = PrioritizedSetting("strict", "BOKEH_STRICT", convert=convert_bool, help=""" Whether validation checks should be strict (i.e. raise errors). """) version = PrioritizedSetting("version", "BOKEH_VERSION", default=None, help=""" What version of BokehJS to use with CDN resources. See the :class:`~bokeh.resources.Resources` class reference for full details. """) xsrf_cookies = PrioritizedSetting("xsrf_cookies", "BOKEH_XSRF_COOKIES", default=False, convert=convert_bool, help=""" Whether to enable Tornado XSRF cookie protection on the Bokeh server. This is only applicable when also using an auth module or custom handlers. See https://www.tornadoweb.org/en/stable/guide/security.html#cross-site-request-forgery-protection for more information about XSRF protection in Tornado. All PUT, POST, and DELETE handlers will need to be appropriately instrumented when this setting is active. """) # Non-settings methods [docs] def bokehjsdir(self): ''' The location of the BokehJS source tree. ''' return bokehjsdir(self.dev) [docs] def css_files(self): ''' The CSS files in the BokehJS directory. ''' js_files = [] for root, dirnames, files in os.walk(self.bokehjsdir()): for fname in files: if fname.endswith(".css"): js_files.append(join(root, fname)) return js_files [docs] def js_files(self): ''' The JS files in the BokehJS directory. ''' js_files = [] for root, dirnames, files in os.walk(self.bokehjsdir()): for fname in files: if fname.endswith(".js"): js_files.append(join(root, fname)) return js_files [docs] def load_config(self, location): ''' Load a user-specified override config file. The file should be a YAML format with ``key: value`` lines. ''' try: self._config_override = yaml.load(open(abspath(location)), Loader=yaml.SafeLoader) except Exception: raise RuntimeError("Could not load Bokeh config file: {}".format(location)) [docs] def secret_key_bytes(self): ''' Return the secret_key, converted to bytes and cached. ''' if not hasattr(self, '_secret_key_bytes'): key = self.secret_key() if key is None: self._secret_key_bytes = None else: self._secret_key_bytes = codecs.encode(key, "utf-8") return self._secret_key_bytes def _try_load_config(self, locations): for location in locations: try: return yaml.load(open(location), Loader=yaml.SafeLoader) except: pass return {} #----------------------------------------------------------------------------- # Private API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Code #----------------------------------------------------------------------------- settings = Settings() if settings.secret_key() is not None: if len(settings.secret_key()) < 32: import warnings warnings.warn("BOKEH_SECRET_KEY is recommended to have at least 32 bytes of entropy chosen with a cryptographically-random algorithm") if settings.sign_sessions() and settings.secret_key() is None: import warnings warnings.warn("BOKEH_SECRET_KEY must be set if BOKEH_SIGN_SESSIONS is set to True")