Change the list of extensions to a dict

The stage-output role accepts a list of extensions to be replaced as txt
so that they can be seen directly from within a web browser.
Using a list means that children jobs cannot add to the parent setting,
only overwrite. Adding support for dicts while preserving, at least for
now, support for lists - to avoid breaking existing implementations.

Change-Id: Ifc4b2070c5844e51acb9ad5d512e9f25f5bdd7ef

roles/stage-output/README.rst

@@ -31,7 +31,7 @@ intended to be used before output fetching in a base job's post-playbook.
 .. zuul:rolevar:: extensions_to_txt
    :default: null
 
-   A list of file extensions to be replaced with .txt when staging.
+   A dict of file extensions to be replaced with .txt when staging.
    This can be useful to ensure that text files with an extension not
    registered in the web server may be viewed via browser when uploaded
    to a file server.
@@ -43,8 +43,9 @@ intended to be used before output fetching in a base job's post-playbook.
    Example:
 
      extensions_to_txt:
-     - conf
+       conf: True
-     - log
+       log: True
+       txt: False
 
      zuul.conf --(staged as)--> zuul_conf.txt
 

roles/stage-output/tasks/main.yaml

@@ -4,9 +4,26 @@
   with_dict: "{{ zuul_copy_output }}"
   register: sources
 
-- name: Build the replace regex
+- name: Build the replace regex when the input is a list
   set_fact:
     extensions_regex: "{{ extensions_to_txt | join('|') | default('__do_not_replace__') }}"
+  when: extensions_to_txt | type_debug == 'list'
+
+- name: Output a warning when input is a list
+  debug:
+    msg: "WARNING: extensions_to_txt is a list, values defined by parents will be overwritten"
+  when: extensions_to_txt | type_debug == 'list'
+
+- name: Build a list when replace regex is a dict
+  set_fact:
+    extensions_regex: "{{ extensions_regex | default('___') }}|{{ item.key }}"
+  with_dict: extensions_to_txt
+  when:
+    - extensions_to_txt | type_debug == 'dict'
+    - item.value == True
+  # NOTE(andreaf) Even if this is only executed for type 'dict', with_dict is
+  # still invoked somehow and it's causing an error when the input is a list
+  ignore_errors: yes
 
 - debug:
     var: extensions_regex