ckanext-activity requires username even if ignore_auth is set

[ThrawnCA]

CKAN version

2.11

Describe the bug

If tests use the helpers.call_action convenience function to call actions that affect the activity stream without providing authentication, the tests will encounter errors, because ckanext-activity expects a user to exist in the context.

Steps to reproduce

Enable 'activity' in the CKAN config.

Run a unit test such as:

from ckan.tests import helpers

def test_call_action(self):
    helpers.call_action('dataset_create', notes="Test")

Expected behavior

If ignore_auth is True, the activity stream should gracefully handle the lack of user information.

Additional details

If possible, please provide the full stack trace of the error raised, or add screenshots to help explain your problem.

src/ckan/ckan/logic/action/create.py:314: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
src/ckan/ckan/logic/__init__.py:596: in wrapped
    signals.action_succeeded.send(
/usr/local/lib/python3.10/site-packages/blinker/base.py:279: in send
    result = receiver(sender, **kwargs)
src/ckan/ckanext/activity/subscriptions.py:167: in package_changed
    _create_package_activity(
src/ckan/ckanext/activity/subscriptions.py:82: in _create_package_activity
    user_obj = _get_user_or_raise(context["user"])

[wardi]

Discussion from the dev call:

• we should update activity_create API to accept no user for actions performed with ignore_auth=True
• before activity was a plugin, actions would directly insert activity rows into the database with a special "no user" user_id value in this case. Might be better to use an empty string in the new implementation.

Other suggestions:

• consider recording how an action was performed/authenticated (e.g. CLI, web, or which exact API token was used) in activities for auditing purposes