Enable support to pass override option to tempestconf

This patch adds the variable tempest_tempestconf_extra_cli_call_overrides
that can be passed as dictionary and will override some default options
in tempestconf.

Change-Id: I1466b04ab377a93d4dd1f62564fcb49b863a1229

defaults/main.yml

@@ -276,6 +276,8 @@ tempest_use_tempestconf: false
 tempest_tempestconf_venv_bin: "/openstack/venvs/tempestconf/bin"
 tempest_tempestconf_pip_packages:
   - python-tempestconf
+tempest_tempestconf_extra_cli_call_overrides:
+  auth.use_dynamic_credentials: true
 
 # Stackviz tarball url
 stackviz_tarball: "https://tarballs.openstack.org/package-stackviz-element/stackviz-latest.tar.gz"

tasks/tempestconf.yml

@@ -30,9 +30,11 @@
     export OS_PROJECT_NAME="{{ keystone_admin_tenant_name }}"
     discover-tempest-config --out etc/tempest.conf \
       --network-id "{{ tempest_neutron_public_network_id }}" \
-      --debug \
       --create \
-      auth.use_dynamic_credentials true
+      {% for key, value in tempest_tempestconf_extra_cli_call_overrides.items() %}
+      {{ key }} {{ value }} \
+      {% endfor %}
+      --debug
   environment:
     OS_PASSWORD: "{{ keystone_auth_admin_password }}"
   args: