Use tempest run for generating subunit results

tempest run under the hood uses stestr and also provides --subunit
option to geneate subunit raw ouput. Instead of using extra stestr
binary use tempest run binary for running tempest and generating
subunit raw output. It also helps to maintain one less dependency
while using tempest from master.

Change-Id: I8dce171bf8d4534d99659096dc9ebd72e8164e2e

defaults/main.yml

@@ -16,8 +16,6 @@
 ## Verbosity Options
 debug: False
 
-stestr_executable: "{{ _stestr_executable | default('stestr') }}"
-
 # Install openstack tempest
 # set the tempest_install_method to source or distro
 # on choosing source it will install from git or venv

tasks/tempest_run.yml

@@ -21,7 +21,7 @@
       then
       . {{ tempest_venv_bin }}/activate
       fi
-      tempest run {% if tempest_run_concurrency is defined %}{% if tempest_run_concurrency | int > 0 %}--concurrency {{ tempest_run_concurrency | int }}{% else %}--serial{% endif %}{% endif %} --whitelist-file {{ tempest_test_whitelist_file_path }}{% if tempest_test_blacklist | length > 0 %} --blacklist-file {{ tempest_test_blacklist_file_path }}{% endif %}
+      tempest run {% if tempest_run_concurrency is defined %}{% if tempest_run_concurrency | int > 0 %}--concurrency {{ tempest_run_concurrency | int }}{% else %}--serial{% endif %}{% endif %} --whitelist-file {{ tempest_test_whitelist_file_path }}{% if tempest_test_blacklist | length > 0 %} --blacklist-file {{ tempest_test_blacklist_file_path }}{% endif %} --subunit > {{ tempest_log_dir }}/testrepository.subunit
     args:
       chdir: "{{ tempest_workspace }}"
       executable: /bin/bash
@@ -31,29 +31,6 @@
       # don't trigger ANSIBLE0013
       - skip_ansible_lint
 
-  always:
-  - name: Generate raw subunit results
-    # Despite not using testrepository, we leave the output filename as
-    # testrepository.subunit as the OpenStack Health dashboard relies on
-    # subunit files with this particular name.
-    # NOTE(mattt): At present we're not placing this file in a valid location
-    # to be used by the OpenStack Health dashboard.
-    shell: |
-      set -e
-      if [ -d {{ tempest_venv_bin }} ];
-      then
-      . {{ tempest_venv_bin }}/activate
-      fi
-      {{ stestr_executable }} last --subunit > {{ tempest_log_dir }}/testrepository.subunit
-    args:
-      chdir: "{{ tempest_workspace }}"
-      executable: /bin/bash
-    changed_when: false
-    failed_when: false
-    tags:
-      # don't trigger ANSIBLE0013
-      - skip_ansible_lint
-
   - name: Generate xml subunit results
     shell: |
       set -e

vars/ubuntu.yml

@@ -16,8 +16,6 @@
 ## APT Cache options
 cache_timeout: 600
 
-_stestr_executable: "{{ (tempest_install_method == 'distro') | ternary('testr', 'stestr') }}"
-
 tempest_distro_packages:
   - git-core
   - libxslt1.1           # required by the python module unittest2