Use global service variables

Instead of overriding each service separatelly it might make
sense for deployers to define some higher level variable that
will be used first or fallback to default variable.

Change-Id: I0b0fdd8f811af07f112d717879a77d05a36403ed

defaults/main.yml

@@ -14,7 +14,7 @@
 # limitations under the License.
 
 # Installation method
-mistral_install_method: "source"
+mistral_install_method: "{{ service_install_method | default('source') }}"
 mistral_venv_python_executable: "{{ openstack_venv_python_executable | default('python2') }}"
 
 # Operating system user & groups
@@ -25,7 +25,7 @@ mistral_system_comment: Mistral Daemons
 mistral_system_user_home: /var/lib/mistral
 
 # Distribution deployment
-mistral_package_state: latest
+mistral_package_state: "{{ package_state | default('latest') }}"
 
 # Source package builds
 mistral_git_repo: https://opendev.org/openstack/mistral
@@ -116,7 +116,7 @@ mistral_db_setup_python_interpreter: "{{ openstack_db_setup_python_interpreter |
 mistral_galera_address: "{{ galera_address | default('127.0.0.1') }}"
 mistral_galera_database: mistral
 mistral_galera_user: mistral
-mistral_galera_port: 3306
+mistral_galera_port: "{{ galera_port | default('3306') }}"
 
 # Configuration options
 mistral_debug: "{{ debug | default(false) }}"
@@ -138,13 +138,13 @@ mistral_service_setup_host_python_interpreter: "{{ openstack_service_setup_host_
 mistral_service_name: mistral
 mistral_service_type: workflowv2
 mistral_service_description: OpenStack Workflow service
-mistral_service_in_ldap: false
+mistral_service_in_ldap: "{{ service_ldap_backend_enabled | default(False) }}"
 mistral_service_user_domain_id: default
 mistral_service_user_name: mistral
 mistral_service_project_domain_id: default
 mistral_service_project_name: service
 mistral_role_name: admin
-mistral_service_region: RegionOne
+mistral_service_region: "{{ service_region | default('RegionOne') }}"
 mistral_service_proto: http
 mistral_service_publicuri_proto: "{{ openstack_service_publicuri_proto | default(mistral_service_proto) }}"
 mistral_service_publicurl: "{{ mistral_service_publicuri_proto }}://{{ external_lb_vip_address }}:{{ mistral_service_port }}/v2"