Add consolidated role for processing subunit

We don't need two roles for testr and stestr. The roles have logic to
check to see if .testrepository or .stestr dirs exist, and the logic
after the subunit extraction is the same. Combine them into a single
role which should do the right thing.

Also, document it.

Change-Id: I833320cf9a932d8e119645eb798ce0c93d854321

playbooks/unittests/post.yaml

@@ -1,4 +1,3 @@
 - hosts: all
   roles:
-    - fetch-testr-output
-    - fetch-stestr-output
+    - fetch-subunit-output

roles/fetch-subunit-output/README.rst

@@ -0,0 +1,12 @@
+Collect subunit outputs
+
+**Role Variables**
+
+.. zuul:rolevar:: zuul_work_dir
+   :default: {{ zuul.project.src_dir }}
+
+   Directory to work in
+
+.. zuul:rolevar:: tox_envlist
+
+   tox environment that was used to run the tests originally.

roles/fetch-subunit-output/defaults/main.yaml

@@ -0,0 +1,2 @@
+---
+zuul_work_dir: "src/{{ zuul.project.canonical_name }}"

roles/fetch-subunit-output/tasks/main.yaml

@@ -0,0 +1,48 @@
+- name: Check for stestr directory
+  stat:
+    path: "{{ zuul_work_dir }}/.stestr"
+  register: stestr_stat
+
+- name: Generate stestr subunit file
+  shell:
+    cmd: ".tox/{{ tox_envlist }}/bin/stestr last --subunit > ./testrepository.subunit"
+    chdir: "{{ zuul_work_dir }}"
+  when:
+    - tox_envlist is defined
+    - stestr_stat.stat.exists
+
+- name: Generate stestr subunit file
+  shell:
+    cmd: "stestr last --subunit > ./testrepository.subunit"
+    chdir: "{{ zuul_work_dir }}"
+  when:
+    - tox_envlist is not defined
+    - stestr_stat.stat.exists
+
+- name: Check for testr directory
+  stat:
+    path: "{{ zuul_work_dir }}/.stestr"
+  register: testr_stat
+  when: not stestr_stat.stat.exists
+
+- name: Generate testrepository.subunit file
+  shell:
+    cmd: ".tox/{{ tox_envlist }}/bin/testr last --subunit > ./testrepository.subunit"
+    chdir: "{{ zuul_work_dir }}"
+  when:
+    - tox_envlist is defined
+    - not stestr_stat.stat.exists
+    - testr_stat.stat.exists
+
+- name: Generate testrepository.subunit file
+  shell:
+    cmd: "testr last --subunit > ./testrepository.subunit"
+    chdir: "{{ zuul_work_dir }}"
+  when:
+    - tox_envlist is not defined
+    - not stestr_stat.stat.exists
+    - testr_stat.stat.exists
+
+- name: Process and fetch subunit results
+  include: process.yaml
+  when: stestr_stat.stat.exists or testr_stat.stat.exists

roles/fetch-subunit-output/tasks/process.yaml

@@ -0,0 +1,19 @@
+- name: Generate testr_results.html file
+  # TODO(pabelanger): We cannot depend on /usr/os-testr-env here!!!
+  command: "/usr/os-testr-env/bin/subunit2html ./testrepository.subunit testr_results.html"
+  args:
+    chdir: "{{ zuul_work_dir }}"
+
+- name: Compress testrepository.subunit file
+  archive:
+    path: "{{ zuul_work_dir }}/testrepository.subunit"
+
+- name: Collect test-results
+  synchronize:
+    dest: "{{ zuul.executor.log_root }}"
+    mode: pull
+    src: "{{ zuul_work_dir }}/{{ item }}"
+    verify_host: true
+  with_items:
+    - "*testr_results.html.gz"
+    - "*testrepository.subunit.gz"