https://github.com/ging/horizon
Tip revision: d6824ae14830362af1412b730256c84a1f7d3067 authored by Jenkins on 14 April 2015, 11:31:57 UTC
Merge "Net name field is not required when creating port"
Merge "Net name field is not required when creating port"
Tip revision: d6824ae
base.py
# Copyright 2012 Nebula, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""
Contains the core classes and functionality that makes Horizon what it is.
This module is considered internal, and should not be relied on directly.
Public APIs are made available through the :mod:`horizon` module and
the classes contained therein.
"""
import collections
import copy
import inspect
import logging
import os
from django.conf import settings
from django.conf.urls import include
from django.conf.urls import patterns
from django.conf.urls import url
from django.core.exceptions import ImproperlyConfigured # noqa
from django.core.urlresolvers import reverse
from django.utils.datastructures import SortedDict
from django.utils.functional import SimpleLazyObject # noqa
from django.utils.importlib import import_module # noqa
from django.utils.module_loading import module_has_submodule # noqa
from django.utils.translation import ugettext_lazy as _
from horizon import conf
from horizon.decorators import _current_component # noqa
from horizon.decorators import require_auth # noqa
from horizon.decorators import require_perms # noqa
from horizon import loaders
LOG = logging.getLogger(__name__)
def _decorate_urlconf(urlpatterns, decorator, *args, **kwargs):
for pattern in urlpatterns:
if getattr(pattern, 'callback', None):
pattern._callback = decorator(pattern.callback, *args, **kwargs)
if getattr(pattern, 'url_patterns', []):
_decorate_urlconf(pattern.url_patterns, decorator, *args, **kwargs)
def access_cached(func):
def inner(self, context):
session = context['request'].session
try:
if session['allowed']['valid_for'] != session.get('token'):
raise KeyError()
except KeyError:
session['allowed'] = {"valid_for": session.get('token')}
key = "%s.%s" % (self.__class__.__module__, self.__class__.__name__)
if key not in session['allowed']:
session['allowed'][key] = func(self, context)
session.modified = True
return session['allowed'][key]
return inner
class NotRegistered(Exception):
pass
class HorizonComponent(object):
policy_rules = None
def __init__(self):
super(HorizonComponent, self).__init__()
if not self.slug:
raise ImproperlyConfigured('Every %s must have a slug.'
% self.__class__)
def __unicode__(self):
name = getattr(self, 'name', u"Unnamed %s" % self.__class__.__name__)
return unicode(name)
def _get_default_urlpatterns(self):
package_string = '.'.join(self.__module__.split('.')[:-1])
if getattr(self, 'urls', None):
try:
mod = import_module('.%s' % self.urls, package_string)
except ImportError:
mod = import_module(self.urls)
urlpatterns = mod.urlpatterns
else:
# Try importing a urls.py from the dashboard package
if module_has_submodule(import_module(package_string), 'urls'):
urls_mod = import_module('.urls', package_string)
urlpatterns = urls_mod.urlpatterns
else:
urlpatterns = patterns('')
return urlpatterns
@access_cached
def can_access(self, context):
"""Return whether the user has role based access to this component.
This method is not intended to be overridden.
The result of the method is stored in per-session cache.
"""
return self.allowed(context)
def allowed(self, context):
"""Checks if the user is allowed to access this component.
This method should be overridden to return the result of
any policy checks required for the user to access this component
when more complex checks are required.
"""
return self._can_access(context['request'])
def _can_access(self, request):
policy_check = getattr(settings, "POLICY_CHECK_FUNCTION", None)
# this check is an OR check rather than an AND check that is the
# default in the policy engine, so calling each rule individually
if policy_check and self.policy_rules:
for rule in self.policy_rules:
if policy_check((rule,), request):
return True
return False
# default to allowed
return True
class Registry(object):
def __init__(self):
self._registry = {}
if not getattr(self, '_registerable_class', None):
raise ImproperlyConfigured('Subclasses of Registry must set a '
'"_registerable_class" property.')
def _register(self, cls):
"""Registers the given class.
If the specified class is already registered then it is ignored.
"""
if not inspect.isclass(cls):
raise ValueError('Only classes may be registered.')
elif not issubclass(cls, self._registerable_class):
raise ValueError('Only %s classes or subclasses may be registered.'
% self._registerable_class.__name__)
if cls not in self._registry:
cls._registered_with = self
self._registry[cls] = cls()
return self._registry[cls]
def _unregister(self, cls):
"""Unregisters the given class.
If the specified class isn't registered, ``NotRegistered`` will
be raised.
"""
if not issubclass(cls, self._registerable_class):
raise ValueError('Only %s classes or subclasses may be '
'unregistered.' % self._registerable_class)
if cls not in self._registry.keys():
raise NotRegistered('%s is not registered' % cls)
del self._registry[cls]
return True
def _registered(self, cls):
if inspect.isclass(cls) and issubclass(cls, self._registerable_class):
found = self._registry.get(cls, None)
if found:
return found
else:
# Allow for fetching by slugs as well.
for registered in self._registry.values():
if registered.slug == cls:
return registered
class_name = self._registerable_class.__name__
if hasattr(self, "_registered_with"):
parent = self._registered_with._registerable_class.__name__
raise NotRegistered('%(type)s with slug "%(slug)s" is not '
'registered with %(parent)s "%(name)s".'
% {"type": class_name,
"slug": cls,
"parent": parent,
"name": self.slug})
else:
slug = getattr(cls, "slug", cls)
raise NotRegistered('%(type)s with slug "%(slug)s" is not '
'registered.' % {"type": class_name,
"slug": slug})
class Panel(HorizonComponent):
"""A base class for defining Horizon dashboard panels.
All Horizon dashboard panels should extend from this class. It provides
the appropriate hooks for automatically constructing URLconfs, and
providing permission-based access control.
.. attribute:: name
The name of the panel. This will be displayed in the
auto-generated navigation and various other places.
Default: ``''``.
.. attribute:: slug
A unique "short name" for the panel. The slug is used as
a component of the URL path for the panel. Default: ``''``.
.. attribute:: permissions
A list of permission names, all of which a user must possess in order
to access any view associated with this panel. This attribute
is combined cumulatively with any permissions required on the
``Dashboard`` class with which it is registered.
.. attribute:: urls
Path to a URLconf of views for this panel using dotted Python
notation. If no value is specified, a file called ``urls.py``
living in the same package as the ``panel.py`` file is used.
Default: ``None``.
.. attribute:: nav
.. method:: nav(context)
The ``nav`` attribute can be either boolean value or a callable
which accepts a ``RequestContext`` object as a single argument
to control whether or not this panel should appear in
automatically-generated navigation. Default: ``True``.
.. attribute:: index_url_name
The ``name`` argument for the URL pattern which corresponds to
the index view for this ``Panel``. This is the view that
:meth:`.Panel.get_absolute_url` will attempt to reverse.
"""
name = ''
slug = ''
urls = None
nav = True
index_url_name = "index"
def __repr__(self):
return "<Panel: %s>" % self.slug
def get_absolute_url(self):
"""Returns the default URL for this panel.
The default URL is defined as the URL pattern with ``name="index"`` in
the URLconf for this panel.
"""
try:
return reverse('horizon:%s:%s:%s' % (self._registered_with.slug,
self.slug,
self.index_url_name))
except Exception as exc:
# Logging here since this will often be called in a template
# where the exception would be hidden.
LOG.info("Error reversing absolute URL for %s: %s" % (self, exc))
raise
@property
def _decorated_urls(self):
urlpatterns = self._get_default_urlpatterns()
# Apply access controls to all views in the patterns
permissions = getattr(self, 'permissions', [])
_decorate_urlconf(urlpatterns, require_perms, permissions)
_decorate_urlconf(urlpatterns, _current_component, panel=self)
# Return the three arguments to django.conf.urls.include
return urlpatterns, self.slug, self.slug
class PanelGroup(object):
"""A container for a set of :class:`~horizon.Panel` classes.
When iterated, it will yield each of the ``Panel`` instances it
contains.
.. attribute:: slug
A unique string to identify this panel group. Required.
.. attribute:: name
A user-friendly name which will be used as the group heading in
places such as the navigation. Default: ``None``.
.. attribute:: panels
A list of panel module names which should be contained within this
grouping.
"""
def __init__(self, dashboard, slug=None, name=None, panels=None):
self.dashboard = dashboard
self.slug = slug or getattr(self, "slug", "default")
self.name = name or getattr(self, "name", None)
# Our panels must be mutable so it can be extended by others.
self.panels = list(panels or getattr(self, "panels", []))
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self.slug)
def __unicode__(self):
return self.name
def __iter__(self):
panel_instances = []
for name in self.panels:
try:
panel_instances.append(self.dashboard.get_panel(name))
except NotRegistered as e:
LOG.debug(e)
return iter(panel_instances)
class Dashboard(Registry, HorizonComponent):
"""A base class for defining Horizon dashboards.
All Horizon dashboards should extend from this base class. It provides the
appropriate hooks for automatic discovery of :class:`~horizon.Panel`
modules, automatically constructing URLconfs, and providing
permission-based access control.
.. attribute:: name
The name of the dashboard. This will be displayed in the
auto-generated navigation and various other places.
Default: ``''``.
.. attribute:: slug
A unique "short name" for the dashboard. The slug is used as
a component of the URL path for the dashboard. Default: ``''``.
.. attribute:: panels
The ``panels`` attribute can be either a flat list containing the name
of each panel **module** which should be loaded as part of this
dashboard, or a list of :class:`~horizon.PanelGroup` classes which
define groups of panels as in the following example::
class SystemPanels(horizon.PanelGroup):
slug = "syspanel"
name = _("System")
panels = ('overview', 'instances', ...)
class Syspanel(horizon.Dashboard):
panels = (SystemPanels,)
Automatically generated navigation will use the order of the
modules in this attribute.
Default: ``[]``.
.. warning::
The values for this attribute should not correspond to the
:attr:`~.Panel.name` attributes of the ``Panel`` classes.
They should be the names of the Python modules in which the
``panel.py`` files live. This is used for the automatic
loading and registration of ``Panel`` classes much like
Django's ``ModelAdmin`` machinery.
Panel modules must be listed in ``panels`` in order to be
discovered by the automatic registration mechanism.
.. attribute:: default_panel
The name of the panel which should be treated as the default
panel for the dashboard, i.e. when you visit the root URL
for this dashboard, that's the panel that is displayed.
Default: ``None``.
.. attribute:: permissions
A list of permission names, all of which a user must possess in order
to access any panel registered with this dashboard. This attribute
is combined cumulatively with any permissions required on individual
:class:`~horizon.Panel` classes.
.. attribute:: urls
Optional path to a URLconf of additional views for this dashboard
which are not connected to specific panels. Default: ``None``.
.. attribute:: nav
.. method:: nav(context)
The ``nav`` attribute can be either boolean value or a callable
which accepts a ``RequestContext`` object as a single argument
to control whether or not this dashboard should appear in
automatically-generated navigation. Default: ``True``.
.. attribute:: public
Boolean value to determine whether this dashboard can be viewed
without being logged in. Defaults to ``False``.
"""
_registerable_class = Panel
name = ''
slug = ''
urls = None
panels = []
default_panel = None
nav = True
public = False
def __repr__(self):
return "<Dashboard: %s>" % self.slug
def __init__(self, *args, **kwargs):
super(Dashboard, self).__init__(*args, **kwargs)
self._panel_groups = None
def get_panel(self, panel):
"""Returns the specified :class:`~horizon.Panel` instance registered
with this dashboard.
"""
return self._registered(panel)
def get_panels(self):
"""Returns the :class:`~horizon.Panel` instances registered with this
dashboard in order, without any panel groupings.
"""
all_panels = []
panel_groups = self.get_panel_groups()
for panel_group in panel_groups.values():
all_panels.extend(panel_group)
return all_panels
def get_panel_group(self, slug):
"""Returns the specified :class:~horizon.PanelGroup
or None if not registered
"""
return self._panel_groups.get(slug)
def get_panel_groups(self):
registered = copy.copy(self._registry)
panel_groups = []
# Gather our known panels
if self._panel_groups is not None:
for panel_group in self._panel_groups.values():
for panel in panel_group:
registered.pop(panel.__class__)
panel_groups.append((panel_group.slug, panel_group))
# Deal with leftovers (such as add-on registrations)
if len(registered):
slugs = [panel.slug for panel in registered.values()]
new_group = PanelGroup(self,
slug="other",
name=_("Other"),
panels=slugs)
panel_groups.append((new_group.slug, new_group))
return SortedDict(panel_groups)
def get_absolute_url(self):
"""Returns the default URL for this dashboard.
The default URL is defined as the URL pattern with ``name="index"``
in the URLconf for the :class:`~horizon.Panel` specified by
:attr:`~horizon.Dashboard.default_panel`.
"""
try:
return self._registered(self.default_panel).get_absolute_url()
except Exception:
# Logging here since this will often be called in a template
# where the exception would be hidden.
LOG.exception("Error reversing absolute URL for %s." % self)
raise
@property
def _decorated_urls(self):
urlpatterns = self._get_default_urlpatterns()
default_panel = None
# Add in each panel's views except for the default view.
for panel in self._registry.values():
if panel.slug == self.default_panel:
default_panel = panel
continue
url_slug = panel.slug.replace('.', '/')
urlpatterns += patterns('',
url(r'^%s/' % url_slug,
include(panel._decorated_urls)))
# Now the default view, which should come last
if not default_panel:
raise NotRegistered('The default panel "%s" is not registered.'
% self.default_panel)
urlpatterns += patterns('',
url(r'',
include(default_panel._decorated_urls)))
# Require login if not public.
if not self.public:
_decorate_urlconf(urlpatterns, require_auth)
# Apply access controls to all views in the patterns
permissions = getattr(self, 'permissions', [])
_decorate_urlconf(urlpatterns, require_perms, permissions)
_decorate_urlconf(urlpatterns, _current_component, dashboard=self)
# Return the three arguments to django.conf.urls.include
return urlpatterns, self.slug, self.slug
def _autodiscover(self):
"""Discovers panels to register from the current dashboard module."""
if getattr(self, "_autodiscover_complete", False):
return
panels_to_discover = []
panel_groups = []
# If we have a flat iterable of panel names, wrap it again so
# we have a consistent structure for the next step.
if all([isinstance(i, basestring) for i in self.panels]):
self.panels = [self.panels]
# Now iterate our panel sets.
for panel_set in self.panels:
# Instantiate PanelGroup classes.
if not isinstance(panel_set, collections.Iterable) and \
issubclass(panel_set, PanelGroup):
panel_group = panel_set(self)
# Check for nested tuples, and convert them to PanelGroups
elif not isinstance(panel_set, PanelGroup):
panel_group = PanelGroup(self, panels=panel_set)
# Put our results into their appropriate places
panels_to_discover.extend(panel_group.panels)
panel_groups.append((panel_group.slug, panel_group))
self._panel_groups = SortedDict(panel_groups)
# Do the actual discovery
package = '.'.join(self.__module__.split('.')[:-1])
mod = import_module(package)
for panel in panels_to_discover:
try:
before_import_registry = copy.copy(self._registry)
import_module('.%s.panel' % panel, package)
except Exception:
self._registry = before_import_registry
if module_has_submodule(mod, panel):
raise
self._autodiscover_complete = True
@classmethod
def register(cls, panel):
"""Registers a :class:`~horizon.Panel` with this dashboard."""
panel_class = Horizon.register_panel(cls, panel)
# Support template loading from panel template directories.
panel_mod = import_module(panel.__module__)
panel_dir = os.path.dirname(panel_mod.__file__)
template_dir = os.path.join(panel_dir, "templates")
if os.path.exists(template_dir):
key = os.path.join(cls.slug, panel.slug)
loaders.panel_template_dirs[key] = template_dir
return panel_class
@classmethod
def unregister(cls, panel):
"""Unregisters a :class:`~horizon.Panel` from this dashboard."""
success = Horizon.unregister_panel(cls, panel)
if success:
# Remove the panel's template directory.
key = os.path.join(cls.slug, panel.slug)
if key in loaders.panel_template_dirs:
del loaders.panel_template_dirs[key]
return success
def allowed(self, context):
"""Checks for role based access for this dashboard.
Checks for access to any panels in the dashboard and of the the
dashboard itself.
This method should be overridden to return the result of
any policy checks required for the user to access this dashboard
when more complex checks are required.
"""
# if the dashboard has policy rules, honor those above individual
# panels
if not self._can_access(context['request']):
return False
# check if access is allowed to a single panel,
# the default for each panel is True
for panel in self.get_panels():
if panel.can_access(context):
return True
return False
class Workflow(object):
pass
try:
from django.utils.functional import empty # noqa
except ImportError:
# Django 1.3 fallback
empty = None
class LazyURLPattern(SimpleLazyObject):
def __iter__(self):
if self._wrapped is empty:
self._setup()
return iter(self._wrapped)
def __reversed__(self):
if self._wrapped is empty:
self._setup()
return reversed(self._wrapped)
def __len__(self):
if self._wrapped is empty:
self._setup()
return len(self._wrapped)
def __getitem__(self, idx):
if self._wrapped is empty:
self._setup()
return self._wrapped[idx]
class Site(Registry, HorizonComponent):
"""The overarching class which encompasses all dashboards and panels."""
# Required for registry
_registerable_class = Dashboard
name = "Horizon"
namespace = 'horizon'
slug = 'horizon'
urls = 'horizon.site_urls'
def __repr__(self):
return u"<Site: %s>" % self.slug
@property
def _conf(self):
return conf.HORIZON_CONFIG
@property
def dashboards(self):
return self._conf['dashboards']
@property
def default_dashboard(self):
return self._conf['default_dashboard']
def register(self, dashboard):
"""Registers a :class:`~horizon.Dashboard` with Horizon."""
return self._register(dashboard)
def unregister(self, dashboard):
"""Unregisters a :class:`~horizon.Dashboard` from Horizon."""
return self._unregister(dashboard)
def registered(self, dashboard):
return self._registered(dashboard)
def register_panel(self, dashboard, panel):
dash_instance = self.registered(dashboard)
return dash_instance._register(panel)
def unregister_panel(self, dashboard, panel):
dash_instance = self.registered(dashboard)
if not dash_instance:
raise NotRegistered("The dashboard %s is not registered."
% dashboard)
return dash_instance._unregister(panel)
def get_dashboard(self, dashboard):
"""Returns the specified :class:`~horizon.Dashboard` instance."""
return self._registered(dashboard)
def get_dashboards(self):
"""Returns an ordered tuple of :class:`~horizon.Dashboard` modules.
Orders dashboards according to the ``"dashboards"`` key in
``HORIZON_CONFIG`` or else returns all registered dashboards
in alphabetical order.
Any remaining :class:`~horizon.Dashboard` classes registered with
Horizon but not listed in ``HORIZON_CONFIG['dashboards']``
will be appended to the end of the list alphabetically.
"""
if self.dashboards:
registered = copy.copy(self._registry)
dashboards = []
for item in self.dashboards:
dashboard = self._registered(item)
dashboards.append(dashboard)
registered.pop(dashboard.__class__)
if len(registered):
extra = registered.values()
extra.sort()
dashboards.extend(extra)
return dashboards
else:
dashboards = self._registry.values()
dashboards.sort()
return dashboards
def get_default_dashboard(self):
"""Returns the default :class:`~horizon.Dashboard` instance.
If ``"default_dashboard"`` is specified in ``HORIZON_CONFIG``
then that dashboard will be returned. If not, the first dashboard
returned by :func:`~horizon.get_dashboards` will be returned.
"""
if self.default_dashboard:
return self._registered(self.default_dashboard)
elif len(self._registry):
return self.get_dashboards()[0]
else:
raise NotRegistered("No dashboard modules have been registered.")
def get_user_home(self, user):
"""Returns the default URL for a particular user.
This method can be used to customize where a user is sent when
they log in, etc. By default it returns the value of
:meth:`get_absolute_url`.
An alternative function can be supplied to customize this behavior
by specifying a either a URL or a function which returns a URL via
the ``"user_home"`` key in ``HORIZON_CONFIG``. Each of these
would be valid::
{"user_home": "/home",} # A URL
{"user_home": "my_module.get_user_home",} # Path to a function
{"user_home": lambda user: "/" + user.name,} # A function
{"user_home": None,} # Will always return the default dashboard
This can be useful if the default dashboard may not be accessible
to all users. When user_home is missing from HORIZON_CONFIG,
it will default to the settings.LOGIN_REDIRECT_URL value.
"""
user_home = self._conf['user_home']
if user_home:
if callable(user_home):
return user_home(user)
elif isinstance(user_home, basestring):
# Assume we've got a URL if there's a slash in it
if '/' in user_home:
return user_home
else:
mod, func = user_home.rsplit(".", 1)
return getattr(import_module(mod), func)(user)
# If it's not callable and not a string, it's wrong.
raise ValueError('The user_home setting must be either a string '
'or a callable object (e.g. a function).')
else:
return self.get_absolute_url()
def get_absolute_url(self):
"""Returns the default URL for Horizon's URLconf.
The default URL is determined by calling
:meth:`~horizon.Dashboard.get_absolute_url`
on the :class:`~horizon.Dashboard` instance returned by
:meth:`~horizon.get_default_dashboard`.
"""
return self.get_default_dashboard().get_absolute_url()
@property
def _lazy_urls(self):
"""Lazy loading for URL patterns.
This method avoids problems associated with attempting to evaluate
the URLconf before the settings module has been loaded.
"""
def url_patterns():
return self._urls()[0]
return LazyURLPattern(url_patterns), self.namespace, self.slug
def _urls(self):
"""Constructs the URLconf for Horizon from registered Dashboards."""
urlpatterns = self._get_default_urlpatterns()
self._autodiscover()
# Discover each dashboard's panels.
for dash in self._registry.values():
dash._autodiscover()
# Load the plugin-based panel configuration
self._load_panel_customization()
# Allow for override modules
if self._conf.get("customization_module", None):
customization_module = self._conf["customization_module"]
bits = customization_module.split('.')
mod_name = bits.pop()
package = '.'.join(bits)
mod = import_module(package)
try:
before_import_registry = copy.copy(self._registry)
import_module('%s.%s' % (package, mod_name))
except Exception:
self._registry = before_import_registry
if module_has_submodule(mod, mod_name):
raise
# Compile the dynamic urlconf.
for dash in self._registry.values():
urlpatterns += patterns('',
url(r'^%s/' % dash.slug,
include(dash._decorated_urls)))
# Return the three arguments to django.conf.urls.include
return urlpatterns, self.namespace, self.slug
def _autodiscover(self):
"""Discovers modules to register from ``settings.INSTALLED_APPS``.
This makes sure that the appropriate modules get imported to register
themselves with Horizon.
"""
if not getattr(self, '_registerable_class', None):
raise ImproperlyConfigured('You must set a '
'"_registerable_class" property '
'in order to use autodiscovery.')
# Discover both dashboards and panels, in that order
for mod_name in ('dashboard', 'panel'):
for app in settings.INSTALLED_APPS:
mod = import_module(app)
try:
before_import_registry = copy.copy(self._registry)
import_module('%s.%s' % (app, mod_name))
except Exception:
self._registry = before_import_registry
if module_has_submodule(mod, mod_name):
raise
def _load_panel_customization(self):
"""Applies the plugin-based panel configurations.
This method parses the panel customization from the ``HORIZON_CONFIG``
and make changes to the dashboard accordingly.
It supports adding, removing and setting default panels on the
dashboard. It also support registering a panel group.
"""
panel_customization = self._conf.get("panel_customization", [])
for config in panel_customization:
if config.get('PANEL'):
self._process_panel_configuration(config)
elif config.get('PANEL_GROUP'):
self._process_panel_group_configuration(config)
else:
LOG.warning("Skipping %s because it doesn't have PANEL or "
"PANEL_GROUP defined.", config.__name__)
def _process_panel_configuration(self, config):
"""Add, remove and set default panels on the dashboard."""
try:
dashboard = config.get('PANEL_DASHBOARD')
if not dashboard:
LOG.warning("Skipping %s because it doesn't have "
"PANEL_DASHBOARD defined.", config.__name__)
return
panel_slug = config.get('PANEL')
dashboard_cls = self.get_dashboard(dashboard)
panel_group = config.get('PANEL_GROUP')
default_panel = config.get('DEFAULT_PANEL')
# Set the default panel
if default_panel:
dashboard_cls.default_panel = default_panel
# Remove the panel
if config.get('REMOVE_PANEL', False):
for panel in dashboard_cls.get_panels():
if panel_slug == panel.slug:
dashboard_cls.unregister(panel.__class__)
elif config.get('ADD_PANEL', None):
# Add the panel to the dashboard
panel_path = config['ADD_PANEL']
mod_path, panel_cls = panel_path.rsplit(".", 1)
try:
mod = import_module(mod_path)
except ImportError:
LOG.warning("Could not load panel: %s", mod_path)
return
panel = getattr(mod, panel_cls)
dashboard_cls.register(panel)
if panel_group:
dashboard_cls.get_panel_group(panel_group).__class__.\
panels.append(panel.slug)
dashboard_cls.get_panel_group(panel_group).\
panels.append(panel.slug)
else:
panels = list(dashboard_cls.panels)
panels.append(panel)
dashboard_cls.panels = tuple(panels)
except Exception as e:
LOG.warning('Could not process panel %(panel)s: %(exc)s',
{'panel': panel_slug, 'exc': e})
def _process_panel_group_configuration(self, config):
"""Adds a panel group to the dashboard."""
panel_group_slug = config.get('PANEL_GROUP')
try:
dashboard = config.get('PANEL_GROUP_DASHBOARD')
if not dashboard:
LOG.warning("Skipping %s because it doesn't have "
"PANEL_GROUP_DASHBOARD defined.", config.__name__)
return
dashboard_cls = self.get_dashboard(dashboard)
panel_group_name = config.get('PANEL_GROUP_NAME')
if not panel_group_name:
LOG.warning("Skipping %s because it doesn't have "
"PANEL_GROUP_NAME defined.", config.__name__)
return
# Create the panel group class
panel_group = type(panel_group_slug,
(PanelGroup, ),
{'slug': panel_group_slug,
'name': panel_group_name,
'panels': []},)
# Add the panel group to dashboard
panels = list(dashboard_cls.panels)
panels.append(panel_group)
dashboard_cls.panels = tuple(panels)
# Trigger the autodiscovery to completely load the new panel group
dashboard_cls._autodiscover_complete = False
dashboard_cls._autodiscover()
except Exception as e:
LOG.warning('Could not process panel group %(panel_group)s: '
'%(exc)s',
{'panel_group': panel_group_slug, 'exc': e})
class HorizonSite(Site):
"""A singleton implementation of Site such that all dealings with horizon
get the same instance no matter what. There can be only one.
"""
_instance = None
def __new__(cls, *args, **kwargs):
if not cls._instance:
cls._instance = super(Site, cls).__new__(cls, *args, **kwargs)
return cls._instance
# The one true Horizon
Horizon = HorizonSite()
