Introduced tempest_extra_config flag for tempest.conf

* tempest_extra_config will contains a dict with section.option as
  a key followed by values like that
  tempest_extra_config:
	identity.admin_v2_api: True
* The above defined values will be overriden in tempest.conf with
  the help of discover-tempest-config tool

* With this flag we can have more control over tempest.conf while
  using it in featureset files.

Change-Id: If787aaf2de0f5a243aceb510f91915db32dc48c1

roles/validate-tempest/README.md

@@ -32,6 +32,8 @@ Role Variables
 * `check_tempest_bugs`: true/false - Will check every bugzilla and launchpad bug in the yaml skip file
 * `tempest_plugins`: list - List of openstack services tempest plugins to be
                      installed
+* `tempest_extra_config`: dict - A dict of tempest configuration which needs to be overridden in tempest.conf,
+                          It should be like section.key: value.
 
 Skip tests file
 ---------------

roles/validate-tempest/defaults/main.yml

@@ -27,6 +27,7 @@ tempest_whitelist_file_src: "whitelist_file.j2"
 tempest_whitelist_file: "whitelist_file.conf"
 tempest_whitelist: []
 tempest_plugins: []
+tempest_extra_config: {}# A dict containing values which needs to be overridden in tempest.conf
 skip_file_src: "skip_file.j2"
 skip_file: skip_file
 tempest_until_failure: false

roles/validate-tempest/templates/configure-tempest.sh.j2

@@ -152,7 +152,6 @@ ${TEMPESTCONF} --out etc/tempest.conf \
   {% endif %}
   compute-feature-enabled.attach_encrypted_volume False \
   network.tenant_network_cidr {{ tenant_network_cidr }} \
-  object-storage.operator_role swiftoperator \
   compute.build_timeout 500 \
   volume-feature-enabled.api_v1 False \
   validation.image_ssh_user cirros \
@@ -162,6 +161,11 @@ ${TEMPESTCONF} --out etc/tempest.conf \
   {% if 'disable-telemetry.yaml' in telemetry_args|default('') %}
   service_available.aodh_plugin False \
   {% endif %}
+  {% if tempest_extra_config %}
+  {% for key, value in tempest_extra_config.iteritems() %}
+  {{ key }} {{ value }} \
+  {% endfor %}
+  {% endif %}
   orchestration.stack_owner_role heat_stack_owner
 
 ### --stop_docs