Allow authentification method to be chosen

To reach Cloudkitty API endpoints, an authentification method must be set.
No authentification or Keystone authentification are allowed.
This should be set in the configuration file, within the DEFAULT block,
using the auth_strategy field.

Task: 4902
Story: 2001168

Change-Id: I3f9d5700e4c2d1a69b5514fd9932a62238ee659c

doc/source/configuration/index.rst

@@ -10,6 +10,31 @@ Edit :file:`/etc/cloudkitty/cloudkitty.conf` to configure cloudkitty.
 Then you need to know which keystone API version you use (which can be
 determined using `openstack endpoint list`)
 
+
+The first thing to set is the authentification method wished to reach Cloudkitty API endpoints.
+
+
+Without authentification
+------------------------
+
+If wanted, you can choose to not set any authentification method.
+This should be set in de DEFAULT block of the configuration file owing to the auth_strategy field:
+
+.. code-block:: ini
+
+    [DEFAULT]
+    verbose = True
+    log_dir = /var/log/cloudkitty
+    # oslo_messaging_rabbit is deprecated
+    transport_url = rabbit://openstack:RABBIT_PASSWORD@RABBIT_HOST
+    auth_strategy = noauth
+
+
+Otherwise, the only other officially implemented authentification method is keystone.
+More methods will be implemented soon.
+It should be set in the DEFAULT configuration block too, with the auth_stategy field.
+
+
 For keystone (identity) API v2 (deprecated)
 -------------------------------------------
 
@@ -20,6 +45,7 @@ For keystone (identity) API v2 (deprecated)
     log_dir = /var/log/cloudkitty
     # oslo_messaging_rabbit is deprecated
     transport_url = rabbit://openstack:RABBIT_PASSWORD@RABBIT_HOST/
+    auth_strategy = keystone
 
     [auth]
     username = cloudkitty
@@ -80,6 +106,7 @@ The following shows the basic configuration items:
     log_dir = /var/log/cloudkitty
     # oslo_messaging_rabbit is deprecated
     transport_url = rabbit://openstack:RABBIT_PASSWORD@RABBIT_HOST/
+    auth_strategy = keystone
 
     [ks_auth]
     auth_type = v3password