Collection content loading (#52194)

* basic plugin loading working (with many hacks)

* task collections working

* play/block-level collection module/action working

* implement PEP302 loader

* implicit package support (no need for __init.py__ in collections)
* provides future options for secure loading of content that shouldn't execute inside controller (eg, actively ignore __init__.py on content/module paths)
* provide hook for synthetic collection setup (eg ansible.core pseudo-collection for specifying built-in plugins without legacy path, etc)

* synthetic package support

* ansible.core.plugins mapping works, others don't

* synthetic collections working for modules/actions

* fix direct-load legacy

* change base package name to ansible_collections

* note

* collection role loading

* expand paths from installed content root vars

* feature complete?

* rename ansible.core to ansible.builtin

* and various sanity fixes

* sanity tweaks

* unittest fixes

* less grabby error handler on has_plugin

* probably need to replace with a or harden callers

* fix win_ping test

* disable module test with explicit file extension; might be able to support in some scenarios, but can't see any other tests that verify that behavior...

* fix unicode conversion issues on py2

* attempt to keep things working-ish on py2.6

* python2.6 test fun round 2

* rename dirs/configs to "collections"

* add wrapper dir for content-adjacent

* fix pythoncheck to use localhost

* unicode tweaks, native/bytes string prefixing

* rename COLLECTION_PATHS to COLLECTIONS_PATHS

* switch to pathspec

* path handling cleanup

* change expensive `all` back to or chain

* unused import cleanup

* quotes tweak

* use wrapped iter/len in Jinja proxy

* var name expansion

* comment seemingly overcomplicated playbook_paths resolution

* drop unnecessary conditional nesting

* eliminate extraneous local

* zap superfluous validation function

* use slice for rolespec NS assembly

* misc naming/unicode fixes

* collection callback loader asks if valid FQ name instead of just '.'
* switch collection role resolution behavior to be internally `text` as much as possible

* misc fixmes

* to_native in exception constructor
* (slightly) detangle tuple accumulation mess in module_utils __init__ walker

* more misc fixmes

* tighten up action dispatch, add unqualified action test

* rename Collection mixin to CollectionSearch

* (attempt to) avoid potential confusion/conflict with builtin collections, etc

* stale fixmes

* tighten up pluginloader collections determination

* sanity test fixes

* ditch regex escape

* clarify comment

* update default collections paths config entry

* use PATH format instead of list

* skip integration tests on Python 2.6

ci_complete

lib/ansible/executor/task_queue_manager.py

@@ -36,6 +36,7 @@ from ansible.playbook.play_context import PlayContext
 from ansible.plugins.loader import callback_loader, strategy_loader, module_loader
 from ansible.plugins.callback import CallbackBase
 from ansible.template import Templar
+from ansible.utils.collection_loader import is_collection_ref
 from ansible.utils.helpers import pct_to_int
 from ansible.vars.hostvars import HostVars
 from ansible.vars.reserved import warn_if_reserved
@@ -167,6 +168,10 @@ class TaskQueueManager:
                                    " see the 2.4 porting guide for details." % callback_obj._load_name, version="2.9")
             self._callback_plugins.append(callback_obj)
 
+        for callback_plugin_name in (c for c in C.DEFAULT_CALLBACK_WHITELIST if is_collection_ref(c)):
+            callback_obj = callback_loader.get(callback_plugin_name)
+            self._callback_plugins.append(callback_obj)
+
         self._callbacks_loaded = True
 
     def run(self, play):