Remove auth_token middleware doc

The auth_token middleware is in python-keystoneclient now so the
docs for it should be there.

Change-Id: I9811b648e92e16b099764f40aa67dd084f445088
This commit is contained in:
Brant Knudson 2014-02-02 10:40:03 -06:00
parent 211bfc3f72
commit 956126d8c8

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@ -22,241 +22,13 @@ Abstract
========
The Keystone middleware architecture supports a common authentication protocol
in use between the OpenStack projects. By using keystone as a common
authentication and authorization mechanisms, the OpenStack project can plug in
in use between the OpenStack projects. By using Keystone as a common
authentication and authorization mechanism, the OpenStack project can plug in
to existing authentication and authorization systems in use by existing
environments.
In this document, we describe the architecture and responsibilities of the
authentication middleware which acts as the internal API mechanism for
OpenStack projects based on the WSGI standard.
The auth_token middleware is no longer hosted in Keystone and has moved to the
python-keystoneclient project. The `documentation regarding authentication
middleware`_ can be found there.
For the architecture of keystone and its services, please see
:doc:`architecture`. This documentation primarily describes the implementation
in ``keystoneclient/middleware/auth_token.py``
(:py:class:`keystoneclient.middleware.auth_token.AuthProtocol`)
Specification Overview
======================
'Authentication' is the process of determining that users are who they say they
are. Typically, 'authentication protocols' such as HTTP Basic Auth, Digest
Access, public key, token, etc, are used to verify a user's identity. In this
document, we define an ''authentication component'' as a software module that
implements an authentication protocol for an OpenStack service. OpenStack is
using a token based mechanism to represent authentication and authorization.
At a high level, an authentication middleware component is a proxy that
intercepts HTTP calls from clients and populates HTTP headers in the request
context for other WSGI middleware or applications to use. The general flow
of the middleware processing is:
* clear any existing authorization headers to prevent forgery
* collect the token from the existing HTTP request headers
* validate the token
* if valid, populate additional headers representing the identity that has
been authenticated and authorized
* in invalid, or not token present, reject the request (HTTPUnauthorized)
or pass along a header indicating the request is unauthorized (configurable
in the middleware)
* if the keystone service is unavailable to validate the token, reject
the request with HTTPServiceUnavailable.
.. _authComponent:
Authentication Component
------------------------
Figure 1. Authentication Component
.. image:: images/graphs_authComp.png
:width: 100%
:height: 180
:alt: An Authentication Component
The middleware may also be configured to operated in a 'delegated mode'.
In this mode, the decision reject an unauthenticated client is delegated to
the OpenStack service, as illustrated below.
Here, requests are forwarded to the OpenStack service with an identity status
message that indicates whether the client's identity has been confirmed or is
indeterminate. It is the OpenStack service that decides whether or not a reject
message should be sent to the client.
.. _authComponentDelegated:
Authentication Component (Delegated Mode)
-----------------------------------------
Figure 2. Authentication Component (Delegated Mode)
.. image:: images/graphs_authCompDelegate.png
:width: 100%
:height: 180
:alt: An Authentication Component (Delegated Mode)
.. _deployStrategies:
Deployment Strategy
===================
The middleware is intended to be used inline with OpenStack wsgi components,
based on the oslo WSGI middleware class. It is typically deployed
as a configuration element in a paste configuration pipeline of other
middleware components, with the pipeline terminating in the service
application. The middleware conforms to the python WSGI standard [PEP-333]_.
In initializing the middleware, a configuration item (which acts like a python
dictionary) is passed to the middleware with relevant configuration options.
Configuration
-------------
The middleware is configured within the config file of the main application as
a WSGI component. Example for the auth_token middleware::
[app:myService]
paste.app_factory = myService:app_factory
[pipeline:main]
pipeline = tokenauth myService
[filter:tokenauth]
paste.filter_factory = keystoneclient.middleware.auth_token:filter_factory
auth_host = 127.0.0.1
auth_port = 35357
auth_protocol = http
auth_uri = http://127.0.0.1:5000/
admin_token = Super999Sekret888Password777
admin_user = admin
admin_password = SuperSekretPassword
admin_tenant_name = service
;Uncomment next line and check ip:port to use memcached to cache tokens
;memcache_servers = 127.0.0.1:11211
;Uncomment next 2 lines if Keystone server is validating client cert
certfile = <path to middleware public cert>
keyfile = <path to middleware private cert>
For services which have separate paste-deploy ini file, auth_token middleware
can be alternatively configured in [keystone_authtoken] section in the main
config file. For example in Nova, all middleware parameters can be removed
from api-paste.ini::
[filter:authtoken]
paste.filter_factory = keystoneclient.middleware.auth_token:filter_factory
and set in nova.conf::
[DEFAULT]
...
auth_strategy=keystone
[keystone_authtoken]
auth_host = 127.0.0.1
auth_port = 35357
auth_protocol = http
auth_uri = http://127.0.0.1:5000/
admin_user = admin
admin_password = SuperSekretPassword
admin_tenant_name = service
Note that middleware parameters in paste config take priority, they must be
removed to use values in [keystone_authtoken] section.
Configuration Options
---------------------
* ``auth_host``: (required) the host providing the keystone service API endpoint
for validating and requesting tokens
* ``admin_token``: either this or the following three options are required. If
set, this is a single shared secret with the keystone configuration used to
validate tokens.
* ``admin_user``, ``admin_password``, ``admin_tenant_name``: if ``admin_token``
is not set, or invalid, then admin_user, admin_password, and
admin_tenant_name are defined as a service account which is expected to have
been previously configured in Keystone to validate user tokens.
* ``delay_auth_decision``: (optional, default `0`) (off). If on, the middleware
will not reject invalid auth requests, but will delegate that decision to
downstream WSGI components.
* ``auth_port``: (optional, default `35357`) the port used to validate tokens
* ``auth_protocol``: (optional, default `https`)
* ``auth_uri``: (optional, defaults to `auth_protocol`://`auth_host`:`auth_port`)
* ``certfile``: (required, if Keystone server requires client cert)
* ``keyfile``: (required, if Keystone server requires client cert) This can be
the same as the certfile if the certfile includes the private key.
Caching for improved response
-----------------------------
In order to prevent every service request, the middleware may be configured
to utilize a cache, and the keystone API returns the tokens with an
expiration (configurable in duration on the keystone service). The middleware
supports memcache based caching.
* ``memcache_servers``: (optonal) if defined, the memcache server(s) to use for
cacheing
* ``token_cache_time``: (optional, default 300 seconds) Only valid if
memcache_servers is defined.
Exchanging User Information
===========================
The middleware expects to find a token representing the user with the header
``X-Auth-Token`` or ``X-Storage-Token``. `X-Storage-Token` is supported for
swift/cloud files and for legacy Rackspace use. If the token isn't present and
the middleware is configured to not delegate auth responsibility, it will
respond to the HTTP request with HTTPUnauthorized, returning the header
``WWW-Authenticate`` with the value `Keystone uri='...'` to indicate where to
request a token. The auth_uri returned is configured with the middleware.
The authentication middleware extends the HTTP request with the header
``X-Identity-Status``. If a request is successfully authenticated, the value
is set to `Confirmed`. If the middleware is delegating the auth decision to the
service, then the status is set to `Invalid` if the auth request was
unsuccessful.
Extended the request with additional User Information
-----------------------------------------------------
The keystone client auth_token middleware extends the request
with additional information if the user has been authenticated.
X-Identity-Status
Provides information on whether the request was authenticated or not.
X-Tenant-Id
The unique, immutable tenant Id
X-Tenant-Name
The unique, but mutable (it can change) tenant name.
X-User-Id
The user id of the user used to log in
X-User-Name
The username used to log in
X-Roles
The roles associated with that user
Deprecated additions
--------------------
X-Tenant
Provides the tenant name. This is to support any legacy implementations
before Keystone switched to an ID/Name schema for tenants.
X-User
The username used to log in. This is to support any legacy implementations
before Keystone switched to an ID/Name schema for tenants.
X-Role
The roles associated with that user
References
==========
.. [PEP-333] pep0333 Phillip J Eby. 'Python Web Server Gateway Interface
v1.0.'' http://www.python.org/dev/peps/pep-0333/.
.. _`documentation regarding authentication middleware`: http://docs.openstack.org/developer/python-keystoneclient/middlewarearchitecture.html