Search path (#16387)

* smarter function to figure out relative paths

takes list of paths in order of relevance to current task
and does the dwim magic on them

* shared function for action plugins using new dwim

unify path construction and error info/messaging
made include and role non exclusive
corrected order and now smarter about tasks
includes inside roles are currently broken as they don't provide the correct role data
make dirname full match to avoid corner cases

* migrated action plugins to new dwim function

reported plugins to use exceptions instead of info

* clarified needle

lib/ansible/plugins/action/copy.py

@@ -23,11 +23,11 @@ import json
 import os
 import tempfile
 
-from ansible import constants as C
+from ansible.errors import AnsibleError
 from ansible.plugins.action import ActionBase
 from ansible.utils.boolean import boolean
 from ansible.utils.hashing import checksum
-from ansible.utils.unicode import to_bytes
+from ansible.utils.unicode import to_bytes, to_str
 
 
 class ActionModule(ActionBase):
@@ -81,27 +81,23 @@ class ActionModule(ActionBase):
                 source = content_tempfile
             except Exception as err:
                 result['failed'] = True
-                result['msg'] = "could not write content temp file: %s" % err
+                result['msg'] = "could not write content temp file: %s" % to_str(err)
                 return result
 
         # if we have first_available_file in our vars
         # look up the files and use the first one we find as src
         elif faf:
             source = self._get_first_available_file(faf, task_vars.get('_original_file', None))
-            if source is None:
-                result['failed'] = True
-                result['msg'] = "could not find src in first_available_file list"
-                return result
-
         elif remote_src:
             result.update(self._execute_module(module_name='copy', module_args=self._task.args, task_vars=task_vars, delete_remote_tmp=False))
             return result
-
-        else:
-            if self._task._role is not None:
-                source = self._loader.path_dwim_relative(self._task._role._role_path, 'files', source)
-            else:
-                source = self._loader.path_dwim_relative(self._loader.get_basedir(), 'files', source)
+        else: # find in expected paths
+            try:
+                source = self._find_needle('files', source)
+            except AnsibleError as e:
+                result['failed'] = True
+                result['msg'] = to_str(e)
+                return result
 
         # A list of source file tuples (full_path, relative_path) which will try to copy to the destination
         source_files = []