Allow Uwsgi configuration overrides

Release note is updated to describe this functionality as well as
general improvments for clarity.

Change-Id: I41838010fc4b6e892bec08035798f096aff5af8f
Related: blueprint keystone-uwsgi

defaults/main.yml

@@ -207,6 +207,7 @@ keystone_uwsgi_ports:
   keystone-wsgi-admin:
     http: 37359
     socket: 5001
+keystone_uwsgi_ini_overrides: {}
 
 # set keystone_ssl to true to enable SSL configuration on the keystone containers
 keystone_ssl: false

releasenotes/notes/os-keystone-uwsgi-and-nginx-options-2157f8e40a7a8156.yaml

@@ -2,18 +2,21 @@
 features:
   - Introduced option to deploy Keystone under Uwsgi. A new variable
     ``keystone_mod_wsgi_enabled`` is introduced to toggle this
-    behavior. The ports used by Uwsgi for socket and http connection
-    for both public and admin Keystone services are configurable
-    (see also the ``keystone_uwsgi_ports`` dictionary variable).
-    Federation features should be considered _experimental_ with
-    this configuration at this time. The default is ``true`` which
-    continues to deploy with mod_wsgi for Apache.
+    behavior. The default is ``true`` which continues to deploy with
+    mod_wsgi for Apache. The ports used by Uwsgi for socket and http
+    connection for both public and admin Keystone services are
+    configurable (see also the ``keystone_uwsgi_ports`` dictionary
+    variable). Other Uwsgi configuration can be overridden by using
+    the ``keystone_uwsgi_ini_overrides`` variable as documented
+    under "Overriding OpenStack configuration defaults" in the
+    OpenStack-Ansible Install Guide. Federation features should be
+    considered _experimental_ with this configuration at this time.
   - Introduced option to deploy Keystone behind Nginx. A new
     variable ``keystone_apache_enabled`` is introduced to toggle
-    this behavior. Additional configuration can be delivered to
+    this behavior.  The default is ``true`` which continues to
+    deploy with Apache. Additional configuration can be delivered to
     Nginx through the use of the ``keystone_nginx_extra_conf`` list
     variable. Federation features are not supported with this
     configuration at this time. Use of this option requires
     ``keystone_mod_wsgi_enabled`` to be set to ``false`` which will
-    deploy Keystone under Uwsgi. The default is ``true`` which
-    continues to deploy with Apache.
+    deploy Keystone under Uwsgi.

tasks/keystone_uwsgi.yml

@@ -20,10 +20,12 @@
     mode: "0711"
 
 - name: Apply uWSGI configuration
-  template:
+  config_template:
     src: "keystone-uwsgi.ini.j2"
     dest: "/etc/uwsgi/{{ item }}.ini"
     mode: "0744"
+    config_overrides: "{{ keystone_uwsgi_ini_overrides }}"
+    config_type: ini
   with_items: keystone_wsgi_program_names
   notify: Restart Keystone APIs