Introspectable configuration

docs/architecture.rst

@@ -11,13 +11,13 @@ be used individually for the authentication style desired.
 Provider HTML Examples
 ======================
 
-Every authentication provider that is available comes with a basic HTML 
-example illustrating the parameters it requires. The template generally 
+Every authentication provider that is available comes with a basic HTML
+example illustrating the parameters it requires. The template generally
 includes a logo when its a third party :term:`identity provider` to help
 a website user find the preferred authentication option.
 
 .. note::
-    
+
     While most websites will redirect to Velruse to handle the authentication
     for a user to login or register, the authentication can be done anytime
     for 'linking' an account to another provider as well.
@@ -47,6 +47,13 @@ Auth Provider's are usually setup under the :class:`~velruse.app.VelruseApp`
 WSGI app, which is a minimal WSGI application that can dispatch to several
 configured Auth Provider's based on a YAML configuration file.
 
+Velruse webservices
+=====================
+
+velruse has some webservices to be queried to know its actual set of providers:
+
+    - /auth_providers_list : JSON mapping of providers and their relative login & process urls
+
 
 UserStore Backends
 ==================

docs/providers.rst

@@ -8,6 +8,25 @@ Authentication Providers supply varying levels of information when
 authentication has occurred. Some of them can also provide API access
 tokens in addition to authenticating a user for sign-on.
 
+Configuration hook
+===================
+You can integrate a python callable at the velruse initialization to configure dynamicly the providers.
+For thus, make a toto python module containing your configuration stuff, for example ::
+
+
+    toto.py:
+        def cfg(config):
+            settings = config.registry.settings
+            settings['velruse.providers']='velruse.providers.foo'
+            settings['velruse.providers.foo.id'] = 'foo'
+            settings['velruse.providers.foo.secret'] = 'bar'
+
+
+In velruse deployment config, add::
+
+        velruse.providers_hook = toto.callable
+
+
 Facebook
 ========
 
@@ -332,7 +351,7 @@ Policy URL
     Site's Privacy Policy URL, overrides the url specified during registration
     of your application with Live Services.
 Return URL
-    Site's Return URL, overrides the url specified during registration of 
+    Site's Return URL, overrides the url specified during registration of
     your application with Live Services. This is not *YOUR* applicaton's end
     point!  This should only be overriden if your registration url is not
     the velruse url.  For example http://YOURDOMAIN.COM/velruse/live/process.
@@ -347,7 +366,7 @@ POST Parameters
 Complete Example:
 
 .. code-block:: html
-    
-    <form action="/velruse/live/login" method="post">
+
+    <form action="/velruse/live/auth" method="post">
     <input type="submit" value="Login with Windows Live" />
     </form>

velruse/app.py

@@ -1,5 +1,7 @@
+import copy
 import logging
 import os
+import re
 
 from pyramid.config import Configurator
 from pyramid.exceptions import ConfigurationError
@@ -13,6 +15,34 @@
 
 log = logging.getLogger(__name__)
 
+re_flags = re.U|re.X|re.S
+
+def auth_providers_list(request):
+    """Return a JSON mapping of the velruse offered providers.
+    This is to be used inside velruse front ends:
+    Something like ::
+
+        {
+            'velruse.providers.github': {
+                      'login'   : 'http://velrusehost/velruse/github/login',
+                      'process' : 'http://velrusehost/velruse/github/process',
+            },
+        }
+
+
+    """
+    settings = request.registry.settings
+    ifs = copy.deepcopy(
+        settings['velruse.providers_infos']
+    )
+    url_keys = ['login', 'process']
+    for item in ifs:
+        for key in ifs[item]:
+            for pattern in url_keys:
+                if re.compile(pattern, re_flags).search(key):
+                    ifs[item][pattern] = request.route_url(ifs[item][key])
+    return ifs
+
 
 @view_config(context='velruse.api.AuthenticationComplete')
 def auth_complete_view(context, request):
@@ -69,6 +99,36 @@ def default_setup(config):
     factory = UnencryptedCookieSessionFactoryConfig(secret)
     config.set_session_factory(factory)
 
+def providers_lookup(config):
+    """Lookup for the providers to activate
+    Can be overridden by settings
+    velruse.providers_lookup = mymodule.hook
+    This can be useful for example if your authentication information
+    is stored on a relational database.
+    EG:
+    toto.py:
+        def cfg(config):
+            settings = config.registry.settings
+            settings['velruse.providers']='velruse.providers.foo'
+            settings['velruse.providers.foo.id'] = 'foo'
+            settings['velruse.providers.foo.secret'] = 'bar'
+
+    and in velruse deployment config:
+
+        velruse.providers_hook = toto.cfg
+    """
+    settings = config.registry.settings
+    providers_hook = settings.get('velruse.providers_hook', '')
+    if providers_hook:
+        providers_hook = config.maybe_dotted(providers_hook)
+        providers_hook(config)
+    providers = []
+    for a in splitlines(
+        settings.get('velruse.providers', '')
+    ):
+        providers.append(a)
+        settings['velruse.providers_infos'][a] = {}
+    return providers
 
 def includeme(config, do_setup=True):
     """Configuration function to make a pyramid app a velruse one."""
@@ -94,14 +154,17 @@ def includeme(config, do_setup=True):
     config.include(store)
 
     # include providers
-    providers = settings.get('velruse.providers', '')
-    providers = splitlines(providers)
+    if not 'velruse.providers_infos' in settings:
+        settings['velruse.providers_infos'] = {}
+    providers = providers_lookup(config)
 
     for provider in providers:
         config.include(provider)
 
     # add the error views
     config.scan(__name__)
+    config.add_route("auth_providers_list", "/auth_providers_list")
+    config.add_view(auth_providers_list, route_name="auth_providers_list", renderer='json')
 
 def make_app(**settings):
     config = Configurator(settings=settings)