fetch-subunit-output: collect additional subunit files

In addition to the main subunit file from zuul_work_dir,
collect the subunit files from the elements (directories)
of the zuul_additional_subunit_dirs list.

The default behavior is unchanged.

Change-Id: Ic3bc76aa104951bcc0c186347196067342e28751

roles/fetch-subunit-output/README.rst

@@ -7,6 +7,13 @@ Collect subunit outputs
 
    Directory to work in. It has to be a fully qualified path.
 
+.. zuul:rolevar:: zuul_additional_subunit_dirs
+   :default: []
+
+   List of additional directories which contains subunit files
+   to collect. The content of zuul_work_dir is always checked,
+   so it should not be added here.
+
 .. zuul:rolevar:: tox_envlist
 
    tox environment that was used to run the tests originally.

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

@@ -1,3 +1,4 @@
 ---
 tox_envlist: ""
+zuul_additional_subunit_dirs: []
 zuul_work_dir: "{{ ansible_user_dir }}/{{ zuul.project.src_dir }}"

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

@@ -9,11 +9,15 @@
     - testr_command.rc == 0
     - testr_command.stdout_lines
   block:
+    - name: Get the list of directories with subunit files
+      set_fact:
+        subunit_dirs: "{{ [ zuul_work_dir ] + zuul_additional_subunit_dirs }}"
 
     - name: Generate subunit file
       shell:
-        cmd: "{{ testr_command.stdout_lines[0] }} last --subunit > ./testrepository.subunit"
-        chdir: "{{ zuul_work_dir }}"
+        cmd: "{{ testr_command.stdout_lines[0] }} last --subunit >>{{ zuul_work_dir }}/testrepository.subunit"
+        chdir: "{{ item }}"
+      loop: "{{ subunit_dirs }}"
 
     - name: Process and fetch subunit results
       include: process.yaml