Add tempest_log_dir variable

This commit overrides tempest_log_dir to point to /var/log/utility,
as that directory is currently assumed in openstack-ansible.

Note that tempest_log_dir will be added to os_tempest in a subsequent
review.

Change-Id: I907b7b416cf03d88c9b015b3265a216c51a0c7da

playbooks/inventory/group_vars/hosts.yml

@@ -285,3 +285,6 @@ haproxy_use_keepalived: "{% if groups.haproxy|length > 1 %}True{% else %}False{%
 # :param group: group of hosts where the module will be loaded
 openstack_host_specific_kernel_modules:
   - { name: "ebtables", pattern: "CONFIG_BRIDGE_NF_EBTABLES", group: "network_hosts" }
+
+## Tempest
+tempest_log_dir: /var/log/utility

playbooks/os-tempest-install.yml

@@ -25,7 +25,7 @@
         - "os-tempest"
     - role: "rsyslog_client"
       rsyslog_client_log_rotate_file: utility_log_rotate
-      rsyslog_client_log_dir: "/var/log/utility"
+      rsyslog_client_log_dir: "{{ tempest_log_dir }}"
       rsyslog_client_config_name: "99-tempest-rsyslog-client.conf"
       tags:
         - "tempest-rsyslog-client"