[feature] Upgrade to channels 4.x

[AviGawande]

• Updated websocket consumer to use AsyncWebsocketConsumer
• Updated routing to use re_path
• Updated handlers to use async/await pattern
• Updated channels dependency to >=4.0.0,<5.0.0

Checklist

• I have read the OpenWISP Contributing Guidelines.
• I have manually tested the changes proposed in this pull request.
• I have written new test cases for new code and/or updated existing tests for changes to existing code.
• I have updated the documentation.

Reference to Existing Issue = #388

Fixes centralize-django-channels

Please open a new issue if there isn't an existing issue yet.

Description of Changes

Please describe these changes.

Screenshot

Please include any relevant screenshots.

[nemesifier]

The build is failing, please run the sample app tests locally with the following command to see if you can replicate:

SAMPLE_APP=1 ./runtests.py

[nemesifier]

The issue still persists.
I was able to replicate the issue with these commands:

mkvirtualenv --python=python3 channels4
pip install -e . && pip install -r requirements-test.txt
SAMPLE_APP=1 ./runtests.py

Test output:

======================================================================
ERROR: openwisp2.sample_notifications.tests.test_websockets (unittest.loader._FailedTest)
----------------------------------------------------------------------
ImportError: Failed to import test module: openwisp2.sample_notifications.tests.test_websockets
Traceback (most recent call last):
  File "/usr/lib/python3.8/unittest/loader.py", line 436, in _find_test_path
    module = self._get_module_from_name(name)
  File "/usr/lib/python3.8/unittest/loader.py", line 377, in _get_module_from_name
    __import__(name)
  File "/home/nemesis/Code/openwisp/openwisp-notifications/tests/openwisp2/sample_notifications/tests/test_websockets.py", line 1, in <module>
    from openwisp_notifications.tests.test_websockets import (
  File "/home/nemesis/Code/openwisp/openwisp-notifications/openwisp_notifications/tests/test_websockets.py", line 9, in <module>
    from channels.testing import WebsocketCommunicator
  File "/home/nemesis/.virtualenvs/channels4/lib/python3.8/site-packages/channels/testing/__init__.py", line 3, in <module>
    from .live import ChannelsLiveServerTestCase  # noqa
  File "/home/nemesis/.virtualenvs/channels4/lib/python3.8/site-packages/channels/testing/live.py", line 3, in <module>
    from daphne.testing import DaphneProcess
ModuleNotFoundError: No module named 'daphne'

Are you able to replicate this issue locally @AviGawande?

[AviGawande]

@nemesifier I tried to replicate the issue but i am getting different error.

======================================================================
ERROR: openwisp2.sample_notifications.tests.test_websockets (unittest.loader._FailedTest)
----------------------------------------------------------------------
ImportError: Failed to import test module: openwisp2.sample_notifications.tests.test_websockets
Traceback (most recent call last):
  File "/usr/lib/python3.10/unittest/loader.py", line 436, in _find_test_path
    module = self._get_module_from_name(name)
  File "/usr/lib/python3.10/unittest/loader.py", line 377, in _get_module_from_name
    __import__(name)
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/tests/openwisp2/sample_notifications/tests/test_websockets.py", line 1, in <module>
    from openwisp_notifications.tests.test_websockets import (
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/openwisp_notifications/tests/test_websockets.py", line 76, in <module>
    class TestNotificationSockets:
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/openwisp_notifications/tests/test_websockets.py", line 77, in TestNotificationSockets
    application = import_string(getattr(settings, 'ASGI_APPLICATION'))
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/django/utils/module_loading.py", line 30, in import_string
    return cached_import(module_path, class_name)
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/django/utils/module_loading.py", line 15, in cached_import
    module = import_module(module_path)
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/tests/openwisp2/asgi.py", line 23, in <module>
    AuthMiddlewareStack(URLRouter(get_routes(consumers)))
TypeError: get_routes() takes 0 positional arguments but 1 was given

I tried changes locally but it didn't worked for notification_update_handler

[nemesifier]

@AviGawande the fact that you get a different error means that probably you're not executing the same steps of the CI build.
Can you look at the steps exeucted by CI build please?
https://github.com/openwisp/openwisp-notifications/blob/master/.github/workflows/build.yml
Ensure you're creating a new python virtualenvironment and executing the same steps, then run:

SAMPLE_APP=1 ./runtests.py.

[AviGawande]

@nemesifier I followed the same steps you mentioned but still got this error.

(env) abhigawande@DESKTOP-K9K53L4:~/projects/openwisp/notification/openwisp-notifications$ ./runtests.py
Traceback (most recent call last):
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/./runtests.py", line 22, in <module>
    execute_from_command_line(args)
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/django/core/management/__init__.py", line 442, in execute_from_command_line
    utility.execute()
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/django/core/management/__init__.py", line 416, in execute
    django.setup()
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/django/__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/django/apps/registry.py", line 116, in populate
    app_config.import_models()
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/django/apps/config.py", line 269, in import_models
    self.models_module = import_module(models_module_name)
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/openwisp_users/models.py", line 10, in <module>
    from .base.models import (
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/openwisp_users/base/models.py", line 47, in <module>
    class AbstractUser(BaseUser):
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/django/db/models/base.py", line 143, in __new__
    new_class.add_to_class("_meta", Options(meta, app_label))
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/django/db/models/base.py", line 371, in add_to_class
    value.contribute_to_class(cls, name)
  File "/home/abhigawande/projects/openwisp/notification/openwisp-notifications/env/lib/python3.10/site-packages/django/db/models/options.py", line 220, in contribute_to_class
    raise TypeError(
TypeError: 'class Meta' got invalid attribute(s): index_together
(env) abhigawande@DESKTOP-K9K53L4:~/projects/openwisp/notification/openwisp-notifications$ 

[nemesifier]

'class Meta' got invalid attribute(s): index_together

@AviGawande please enable your python virtualenv and tell me what's the output of the following command?

pip freeze | grep -i "Django=="

[AviGawande]

@nemesifier my venv is activated but still this issue persists.
Output:

(env) abhigawande@DESKTOP-K9K53L4:~/projects/openwisp/notification/openwisp-notifications$ pip freeze | grep -i "Django=="
Django==3.2.25

[nemesifier]

@AviGawande make sure you you have Django 4.2, not sure channels 4 supports Django 3.2 (please check). Make also sure your openwisp-notifications fork is installed in your python virtual env.

[AviGawande]

@nemesifier Sure,I am thinking of brute forcing this issue ,means i will close this PR and test and build the changes locally and will then Raise PR.