264 lines
9.7 KiB
Python
264 lines
9.7 KiB
Python
|
# -*- coding: utf-8 -*-
|
||
|
|
"""
|
||
|
|
flask.config
|
||
|
|
~~~~~~~~~~~~
|
||
|
|
|
||
|
|
Implements the configuration related objects.
|
||
|
|
|
||
|
|
:copyright: (c) 2015 by Armin Ronacher.
|
||
|
|
:license: BSD, see LICENSE for more details.
|
||
|
|
"""
|
||
|
|
|
||
|
|
import os
|
||
|
|
import types
|
||
|
|
import errno
|
||
|
|
|
||
|
|
from werkzeug.utils import import_string
|
||
|
|
from ._compat import string_types, iteritems
|
||
|
|
from . import json
|
||
|
|
|
||
|
|
|
||
|
|
class ConfigAttribute(object):
|
||
|
|
"""Makes an attribute forward to the config"""
|
||
|
|
|
||
|
|
def __init__(self, name, get_converter=None):
|
||
|
|
self.__name__ = name
|
||
|
|
self.get_converter = get_converter
|
||
|
|
|
||
|
|
def __get__(self, obj, type=None):
|
||
|
|
if obj is None:
|
||
|
|
return self
|
||
|
|
rv = obj.config[self.__name__]
|
||
|
|
if self.get_converter is not None:
|
||
|
|
rv = self.get_converter(rv)
|
||
|
|
return rv
|
||
|
|
|
||
|
|
def __set__(self, obj, value):
|
||
|
|
obj.config[self.__name__] = value
|
||
|
|
|
||
|
|
|
||
|
|
class Config(dict):
|
||
|
|
"""Works exactly like a dict but provides ways to fill it from files
|
||
|
|
or special dictionaries. There are two common patterns to populate the
|
||
|
|
config.
|
||
|
|
|
||
|
|
Either you can fill the config from a config file::
|
||
|
|
|
||
|
|
app.config.from_pyfile('yourconfig.cfg')
|
||
|
|
|
||
|
|
Or alternatively you can define the configuration options in the
|
||
|
|
module that calls :meth:`from_object` or provide an import path to
|
||
|
|
a module that should be loaded. It is also possible to tell it to
|
||
|
|
use the same module and with that provide the configuration values
|
||
|
|
just before the call::
|
||
|
|
|
||
|
|
DEBUG = True
|
||
|
|
SECRET_KEY = 'development key'
|
||
|
|
app.config.from_object(__name__)
|
||
|
|
|
||
|
|
In both cases (loading from any Python file or loading from modules),
|
||
|
|
only uppercase keys are added to the config. This makes it possible to use
|
||
|
|
lowercase values in the config file for temporary values that are not added
|
||
|
|
to the config or to define the config keys in the same file that implements
|
||
|
|
the application.
|
||
|
|
|
||
|
|
Probably the most interesting way to load configurations is from an
|
||
|
|
environment variable pointing to a file::
|
||
|
|
|
||
|
|
app.config.from_envvar('YOURAPPLICATION_SETTINGS')
|
||
|
|
|
||
|
|
In this case before launching the application you have to set this
|
||
|
|
environment variable to the file you want to use. On Linux and OS X
|
||
|
|
use the export statement::
|
||
|
|
|
||
|
|
export YOURAPPLICATION_SETTINGS='/path/to/config/file'
|
||
|
|
|
||
|
|
On windows use `set` instead.
|
||
|
|
|
||
|
|
:param root_path: path to which files are read relative from. When the
|
||
|
|
config object is created by the application, this is
|
||
|
|
the application's :attr:`~flask.Flask.root_path`.
|
||
|
|
:param defaults: an optional dictionary of default values
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(self, root_path, defaults=None):
|
||
|
|
dict.__init__(self, defaults or {})
|
||
|
|
self.root_path = root_path
|
||
|
|
|
||
|
|
def from_envvar(self, variable_name, silent=False):
|
||
|
|
"""Loads a configuration from an environment variable pointing to
|
||
|
|
a configuration file. This is basically just a shortcut with nicer
|
||
|
|
error messages for this line of code::
|
||
|
|
|
||
|
|
app.config.from_pyfile(os.environ['YOURAPPLICATION_SETTINGS'])
|
||
|
|
|
||
|
|
:param variable_name: name of the environment variable
|
||
|
|
:param silent: set to ``True`` if you want silent failure for missing
|
||
|
|
files.
|
||
|
|
:return: bool. ``True`` if able to load config, ``False`` otherwise.
|
||
|
|
"""
|
||
|
|
rv = os.environ.get(variable_name)
|
||
|
|
if not rv:
|
||
|
|
if silent:
|
||
|
|
return False
|
||
|
|
raise RuntimeError('The environment variable %r is not set '
|
||
|
|
'and as such configuration could not be '
|
||
|
|
'loaded. Set this variable and make it '
|
||
|
|
'point to a configuration file' %
|
||
|
|
variable_name)
|
||
|
|
return self.from_pyfile(rv, silent=silent)
|
||
|
|
|
||
|
|
def from_pyfile(self, filename, silent=False):
|
||
|
|
"""Updates the values in the config from a Python file. This function
|
||
|
|
behaves as if the file was imported as module with the
|
||
|
|
:meth:`from_object` function.
|
||
|
|
|
||
|
|
:param filename: the filename of the config. This can either be an
|
||
|
|
absolute filename or a filename relative to the
|
||
|
|
root path.
|
||
|
|
:param silent: set to ``True`` if you want silent failure for missing
|
||
|
|
files.
|
||
|
|
|
||
|
|
.. versionadded:: 0.7
|
||
|
|
`silent` parameter.
|
||
|
|
"""
|
||
|
|
filename = os.path.join(self.root_path, filename)
|
||
|
|
d = types.ModuleType('config')
|
||
|
|
d.__file__ = filename
|
||
|
|
try:
|
||
|
|
with open(filename, mode='rb') as config_file:
|
||
|
|
exec(compile(config_file.read(), filename, 'exec'), d.__dict__)
|
||
|
|
except IOError as e:
|
||
|
|
if silent and e.errno in (errno.ENOENT, errno.EISDIR):
|
||
|
|
return False
|
||
|
|
e.strerror = 'Unable to load configuration file (%s)' % e.strerror
|
||
|
|
raise
|
||
|
|
self.from_object(d)
|
||
|
|
return True
|
||
|
|
|
||
|
|
def from_object(self, obj):
|
||
|
|
"""Updates the values from the given object. An object can be of one
|
||
|
|
of the following two types:
|
||
|
|
|
||
|
|
- a string: in this case the object with that name will be imported
|
||
|
|
- an actual object reference: that object is used directly
|
||
|
|
|
||
|
|
Objects are usually either modules or classes. :meth:`from_object`
|
||
|
|
loads only the uppercase attributes of the module/class. A ``dict``
|
||
|
|
object will not work with :meth:`from_object` because the keys of a
|
||
|
|
``dict`` are not attributes of the ``dict`` class.
|
||
|
|
|
||
|
|
Example of module-based configuration::
|
||
|
|
|
||
|
|
app.config.from_object('yourapplication.default_config')
|
||
|
|
from yourapplication import default_config
|
||
|
|
app.config.from_object(default_config)
|
||
|
|
|
||
|
|
You should not use this function to load the actual configuration but
|
||
|
|
rather configuration defaults. The actual config should be loaded
|
||
|
|
with :meth:`from_pyfile` and ideally from a location not within the
|
||
|
|
package because the package might be installed system wide.
|
||
|
|
|
||
|
|
See :ref:`config-dev-prod` for an example of class-based configuration
|
||
|
|
using :meth:`from_object`.
|
||
|
|
|
||
|
|
:param obj: an import name or object
|
||
|
|
"""
|
||
|
|
if isinstance(obj, string_types):
|
||
|
|
obj = import_string(obj)
|
||
|
|
for key in dir(obj):
|
||
|
|
if key.isupper():
|
||
|
|
self[key] = getattr(obj, key)
|
||
|
|
|
||
|
|
def from_json(self, filename, silent=False):
|
||
|
|
"""Updates the values in the config from a JSON file. This function
|
||
|
|
behaves as if the JSON object was a dictionary and passed to the
|
||
|
|
:meth:`from_mapping` function.
|
||
|
|
|
||
|
|
:param filename: the filename of the JSON file. This can either be an
|
||
|
|
absolute filename or a filename relative to the
|
||
|
|
root path.
|
||
|
|
:param silent: set to ``True`` if you want silent failure for missing
|
||
|
|
files.
|
||
|
|
|
||
|
|
.. versionadded:: 0.11
|
||
|
|
"""
|
||
|
|
filename = os.path.join(self.root_path, filename)
|
||
|
|
|
||
|
|
try:
|
||
|
|
with open(filename) as json_file:
|
||
|
|
obj = json.loads(json_file.read())
|
||
|
|
except IOError as e:
|
||
|
|
if silent and e.errno in (errno.ENOENT, errno.EISDIR):
|
||
|
|
return False
|
||
|
|
e.strerror = 'Unable to load configuration file (%s)' % e.strerror
|
||
|
|
raise
|
||
|
|
return self.from_mapping(obj)
|
||
|
|
|
||
|
|
def from_mapping(self, *mapping, **kwargs):
|
||
|
|
"""Updates the config like :meth:`update` ignoring items with non-upper
|
||
|
|
keys.
|
||
|
|
|
||
|
|
.. versionadded:: 0.11
|
||
|
|
"""
|
||
|
|
mappings = []
|
||
|
|
if len(mapping) == 1:
|
||
|
|
if hasattr(mapping[0], 'items'):
|
||
|
|
mappings.append(mapping[0].items())
|
||
|
|
else:
|
||
|
|
mappings.append(mapping[0])
|
||
|
|
elif len(mapping) > 1:
|
||
|
|
raise TypeError(
|
||
|
|
'expected at most 1 positional argument, got %d' % len(mapping)
|
||
|
|
)
|
||
|
|
mappings.append(kwargs.items())
|
||
|
|
for mapping in mappings:
|
||
|
|
for (key, value) in mapping:
|
||
|
|
if key.isupper():
|
||
|
|
self[key] = value
|
||
|
|
return True
|
||
|
|
|
||
|
|
def get_namespace(self, namespace, lowercase=True, trim_namespace=True):
|
||
|
|
"""Returns a dictionary containing a subset of configuration options
|
||
|
|
that match the specified namespace/prefix. Example usage::
|
||
|
|
|
||
|
|
app.config['IMAGE_STORE_TYPE'] = 'fs'
|
||
|
|
app.config['IMAGE_STORE_PATH'] = '/var/app/images'
|
||
|
|
app.config['IMAGE_STORE_BASE_URL'] = 'http://img.website.com'
|
||
|
|
image_store_config = app.config.get_namespace('IMAGE_STORE_')
|
||
|
|
|
||
|
|
The resulting dictionary `image_store_config` would look like::
|
||
|
|
|
||
|
|
{
|
||
|
|
'type': 'fs',
|
||
|
|
'path': '/var/app/images',
|
||
|
|
'base_url': 'http://img.website.com'
|
||
|
|
}
|
||
|
|
|
||
|
|
This is often useful when configuration options map directly to
|
||
|
|
keyword arguments in functions or class constructors.
|
||
|
|
|
||
|
|
:param namespace: a configuration namespace
|
||
|
|
:param lowercase: a flag indicating if the keys of the resulting
|
||
|
|
dictionary should be lowercase
|
||
|
|
:param trim_namespace: a flag indicating if the keys of the resulting
|
||
|
|
dictionary should not include the namespace
|
||
|
|
|
||
|
|
.. versionadded:: 0.11
|
||
|
|
"""
|
||
|
|
rv = {}
|
||
|
|
for k, v in iteritems(self):
|
||
|
|
if not k.startswith(namespace):
|
||
|
|
continue
|
||
|
|
if trim_namespace:
|
||
|
|
key = k[len(namespace):]
|
||
|
|
else:
|
||
|
|
key = k
|
||
|
|
if lowercase:
|
||
|
|
key = key.lower()
|
||
|
|
rv[key] = v
|
||
|
|
return rv
|
||
|
|
|
||
|
|
def __repr__(self):
|
||
|
|
return '<%s %s>' % (self.__class__.__name__, dict.__repr__(self))
|