Add fetch-stestr-output role

This commit adds a new role for jobs that run stestr instead of
testrepository. This will generate the output using stestr for those
cases like we do with testr for the old jobs which leverage
testrepository. This change is the dual of the jenkins script patch:
I1fc3b146e99e3484fa009b227ee5d0aeb6ed6084

Change-Id: Ibf652801507ad2845281dd540b4007b04875b2ae

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

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

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

@@ -0,0 +1,23 @@
+- name: Register stestr directory
+  stat:
+    path: "{{ zuul_work_dir }}/.stestr"
+  register: stestr_stat
+
+- name: Process testr artifacts
+  include: process.yaml
+  when:
+    - stestr_stat.stat.exists
+
+- name: Collect test-results
+  synchronize:
+    dest: "{{ zuul.executor.log_root }}"
+    mode: pull
+    rsync_opts:
+      - "--ignore-missing-args"
+    src: "{{ zuul_work_dir }}/{{ item }}"
+    verify_host: true
+  with_items:
+    - "*testr_results.html.gz"
+    - "*testrepository.subunit.gz"
+  when:
+    - stestr_stat.stat.exists

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

@@ -0,0 +1,31 @@
+- name: Generate testrepository.subunit file
+  shell: ".tox/{{ tox_envlist }}/bin/stestr last --subunit > ./testrepository.subunit"
+  args:
+    chdir: "{{ zuul_work_dir }}"
+
+- name: Generate testr_results.html file
+  command: "/usr/os-testr-env/bin/subunit2html ./testrepository.subunit testr_results.html"
+  args:
+    chdir: "{{ zuul_work_dir }}"
+
+- name: Register testrepository.subunit file
+  stat:
+    path: "{{ zuul_work_dir }}/testrepository.subunit"
+  register: p
+
+- name: Compress testrepository.subunit file
+  archive:
+    path: "{{ p.stat.path }}"
+  when:
+    - p.stat.exists
+
+- name: Register testr_results.html file
+  stat:
+    path: "{{ zuul_work_dir }}/testr_results.html"
+  register: html
+
+- name: Compress testr_results.html file
+  archive:
+    path: "{{ html.stat.path }}"
+  when:
+    - html.stat.exists

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

@@ -19,3 +19,5 @@
   with_items:
     - "*testr_results.html.gz"
     - "*testrepository.subunit.gz"
+  when:
+    - testrepository_stat.stat.exists