Update documentation regarding deprecated option

This commit updates documentation on 'drivers' config option as
its no longer required.

Implements blueprint enable-drivers-by-default
Change-Id: I48514de022708ce6595fd6be40ac2ab5884b4f4d

doc/source/admin/deployment.rst

@@ -51,11 +51,6 @@ means that even if you specify no options Congress will run.
 The options most important to Congress are described below, all of which
 appear under the [DEFAULT] section of the configuration file.
 
-``drivers``
-    The list of permitted datasource drivers.  Default is the empty list.
-    The list is a comma separated list of Python class paths. For example:
-    drivers = congress.datasources.neutronv2_driver.NeutronV2Driver,congress.datasources.glancev2_driver.GlanceV2Driver
-
 ``datasource_sync_period``
     The number of seconds to wait between synchronizing datasource config
     from the database.  Default is 0.

doc/source/install/index.rst

@@ -132,7 +132,6 @@ of the :ref:`Deployment <deployment>` document. Note: you may have to run the co
 There are several sections in the congress/etc/congress.conf.sample file you may want to change:
 
 * [DEFAULT] Section
-    - drivers
     - auth_strategy
 * "From oslo.log" Section
     - log_file
@@ -140,13 +139,6 @@ There are several sections in the congress/etc/congress.conf.sample file you may
 * [database] Section
     - connection
 
-Add drivers:
-
-.. code-block:: text
-
-  drivers = congress.datasources.neutronv2_driver.NeutronV2Driver,congress.datasources.glancev2_driver.GlanceV2Driver,congress.datasources.nova_driver.NovaDriver,congress.datasources.keystone_driver.KeystoneDriver,congress.datasources.cinder_driver.CinderDriver,congress.datasources.swift_driver.SwiftDriver,congress.datasources.plexxi_driver.PlexxiDriver,congress.datasources.vCenter_driver.VCenterDriver,congress.datasources.murano_driver.MuranoDriver,congress.datasources.ironic_driver.IronicDriver,congress.datasources.aodh_driver.AodhDriver,congress.datasources.doctor_driver.DoctorDriver,congress.datasources.heatv1_driver.HeatV1Driver,congress.datasources.keystonev3_driver.KeystoneV3Driver,congress.datasources.monasca_driver.MonascaDriver,congress.datasources.neutronv2_qos_driver.NeutronV2QosDriver,congress.datasources.mistral_driver.MistralDriver
-
-
 The default auth_strategy is keystone. To set Congress to use no authorization strategy:
 
 .. code-block:: text
@@ -173,7 +165,6 @@ A bare-bones congress.conf is as follows:
 
   [DEFAULT]
   auth_strategy = noauth
-  drivers = congress.datasources.neutronv2_driver.NeutronV2Driver,congress.datasources.glancev2_driver.GlanceV2Driver,congress.datasources.nova_driver.NovaDriver,congress.datasources.keystone_driver.KeystoneDriver,congress.datasources.cinder_driver.CinderDriver,congress.datasources.swift_driver.SwiftDriver,congress.datasources.plexxi_driver.PlexxiDriver,congress.datasources.vCenter_driver.VCenterDriver,congress.datasources.murano_driver.MuranoDriver,congress.datasources.ironic_driver.IronicDriver,congress.datasources.aodh_driver.AodhDriver,congress.datasources.doctor_driver.DoctorDriver,congress.datasources.heatv1_driver.HeatV1Driver,congress.datasources.keystonev3_driver.KeystoneV3Driver,congress.datasources.monasca_driver.MonascaDriver,congress.datasources.neutronv2_qos_driver.NeutronV2QosDriver,congress.datasources.mistral_driver.MistralDriver
   log_file=congress.log
   log_dir=/var/log/congress
   [database]

doc/source/user/api.rst

@@ -135,9 +135,6 @@ GET     .../drivers              List drivers
 GET     .../drivers/<driver-id>  Read driver properties
 ======= ======================== ==============================================
 
-Drivers were deprecated in Liberty, but the design changed slightly so that
-we could retain them.
-
 
 6. Data sources (/v1/)
 ======================

doc/source/user/cloudservices.rst

@@ -48,23 +48,27 @@ write policy that references the tables populated by that driver.
 
 2.1 Driver installation
 -----------------------
-To install a new driver, you must add its location to the Congress
-configuration file and restart the server.  Congress has a single
-configuration parameter (called `drivers`) that is a list of all the
-installed drivers.  To install a new driver, simply add to this list
-and restart.
+All the existing drivers would be automatically loaded by congress on startup.
+To disable any of the existing driver, it needs to be added to ``disable_drivers``
+config option::
 
-For example, to install the Neutron driver, you add the following to the
-list of drivers in the configuration file::
+    disabled_drivers = nova, plexxi
 
-  congress.datasources.neutronv2_driver.NeutronV2Driver
+To list all the currently supported drivers by congress::
 
-If you have Nova and Neutron installed, you configure Congress as::
+    openstack congress driver list
 
-  drivers = congress.datasources.neutronv2_driver.NeutronV2Driver,congress.datasources.nova_driver.NovaDriver
+To install any new driver, you must add its entry point to congress setup.cfg
+and install. On service restart, it would be automatically loaded to congress.
+
+For any downstream driver, entry point can be added to ``custom_driver_endpoints``
+config option. On service restart, the Congress will load the same along with
+other drivers::
+
+   custom_driver_endpoints = 'test=congress.datasources.test_driver:TestDriver'
 
 
-2.2 Driver configuration (DEPRECATED) and writing policy
+2.2 Driver configuration and writing policy
 --------------------------------------------------------
 Once the driver code is in place, you can use it to create a `datasource` whose
 data is available to Congress policies.  To create a datasource, you use the API and