stage-output: Add the ability to add .txt extensions to files

So that this can more easily work with files like '/var/log/syslog',
make it so that if the user specifies "logs_txt" then the file gets
a .txt extension before being placed in the logs directory.

The existing extensions_to_txt variable doesn't work for this because
it requires an existing extension.

Change-Id: I34fea0c44030c04a5540d6b62976557143289196

roles/stage-output/README.rst

@@ -23,6 +23,16 @@ intended to be used before output fetching in a base job's post-playbook.
    null overrides the will of a parent job to copy something instructing
    not to copy.
 
+   If the type is suffixed with ``_txt``, then the item will have
+   ``.txt`` appended to its name.  For example::
+
+   .. code-block:: yaml
+
+      zuul_copy_output:
+        /var/log/syslog: logs_txt
+
+   Will copy ``/var/log/syslog`` to ``logs/syslog.txt``.
+
 .. zuul:rolevar:: stage_dir
    :default: {{ ansible_user_dir }}
 

roles/stage-output/tasks/main.yaml

@@ -27,12 +27,13 @@
 # NOTE(andreaf) Files or folders that start with a '.' are renamed to starting
 # with an '_' else they would not be visible in the logs folder once uploaded.
 # Extension changes are handled later via find as we want to rename files
-# included of folders specified in `zuul_copy_output`.
+# included of folders specified in `zuul_copy_output` (except for logs_txt,
+# which is handled here).
 - name: Set source and destination for files and folders
   set_fact:
     source: "{{ item.stat.path }}"
-    dest: "{{ item.item.value }}/{{ item.stat.path|basename|regex_replace('^(\\..*)$', '_\\1') }}"
-    type: "{{ item.item.value }}"
+    dest: "{{ item.item.value.split('_')[0] }}/{{ item.stat.path|basename|regex_replace('^(\\..*)$', '_\\1') }}{% if item.item.value.endswith('_txt') %}.txt{% endif %}"
+    type: "{{ item.item.value.split('_')[0] }}"
   with_items: "{{ sources.results }}"
   when:
     - item.stat.exists