Upgrade Wagtail to latest LTS version 2.11

[patphongs]

Summary

What we're after:
To stay up to date with the Wagtail version releases, we should try and upgrade to the latest LTS version of Wagtail, version 2.11.

Completion criteria

• Wagtail is upgraded to version 2.11

Tech steps or considerations

When attempting to upgrade, you will see many additional migrations and app start up errors. We should trouble shoot this during the upgrade to see how we can make the upgrade feasible.

Migrations needed during upgrade:

  Applying wagtailcore.0042_index_on_pagerevision_approved_go_live_at... OK
  Applying wagtailcore.0043_lock_fields... OK
  Applying wagtailcore.0044_add_unlock_grouppagepermission... OK
  Applying wagtailcore.0045_assign_unlock_grouppagepermission... OK
  Applying wagtailcore.0046_site_name_remove_null... OK
  Applying wagtailcore.0047_add_workflow_models... OK
  Applying wagtailcore.0048_add_default_workflows... OK
  Applying wagtailcore.0049_taskstate_finished_by... OK
  Applying wagtailcore.0050_workflow_rejected_to_needs_changes... OK
  Applying wagtailcore.0051_taskstate_comment... OK
  Applying wagtailcore.0052_pagelogentry... OK
  Applying wagtailcore.0053_locale_model... OK
  Applying wagtailcore.0054_initial_locale... OK
  Applying wagtailcore.0055_page_locale_fields... OK
  Applying wagtailcore.0056_page_locale_fields_populate... OK
  Applying wagtailcore.0057_page_locale_fields_notnull... OK
  Applying wagtailcore.0058_page_alias_of... OK
  Applying wagtailcore.0059_apply_collection_ordering... OK
  Applying wagtailforms.0004_add_verbose_name_plural... OK
  Applying wagtailimages.0022_uploadedimage... OK

Application start up errors:

Exception in thread django-main-thread:
Traceback (most recent call last):
  File "/.pyenv/versions/lib/python3.7/site-packages/django/core/servers/basehttp.py", line 45, in get_internal_wsgi_application
    return import_string(app_path)
  File "/.pyenv/versions/lib/python3.7/site-packages/django/utils/module_loading.py", line 17, in import_string
    module = import_module(module_path)
  File "/.pyenv/versions/3.7.7/lib/python3.7/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/dev/fec-cms/fec/fec/wsgi.py", line 18, in <module>
    application = get_wsgi_application()
  File "/.pyenv/versions/lib/python3.7/site-packages/django/core/wsgi.py", line 13, in get_wsgi_application
    return WSGIHandler()
  File "/.pyenv/versions/lib/python3.7/site-packages/django/core/handlers/wsgi.py", line 135, in __init__
    self.load_middleware()
  File "/.pyenv/versions/lib/python3.7/site-packages/django/core/handlers/base.py", line 35, in load_middleware
    middleware = import_string(middleware_path)
  File "/.pyenv/versions/lib/python3.7/site-packages/django/utils/module_loading.py", line 17, in import_string
    module = import_module(module_path)
  File "/.pyenv/versions/3.7.7/lib/python3.7/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 965, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'wagtail.core.middleware'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/.pyenv/versions/3.7.7/lib/python3.7/threading.py", line 926, in _bootstrap_inner
    self.run()
  File "/.pyenv/versions/3.7.7/lib/python3.7/threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
  File "/.pyenv/versions/lib/python3.7/site-packages/django/utils/autoreload.py", line 54, in wrapper
    fn(*args, **kwargs)
  File "/.pyenv/versions/lib/python3.7/site-packages/django/core/management/commands/runserver.py", line 137, in inner_run
    handler = self.get_handler(*args, **options)
  File "/.pyenv/versions/lib/python3.7/site-packages/django/contrib/staticfiles/management/commands/runserver.py", line 27, in get_handler
    handler = super().get_handler(*args, **options)
  File "/.pyenv/versions/lib/python3.7/site-packages/django/core/management/commands/runserver.py", line 64, in get_handler
    return get_internal_wsgi_application()
  File "/.pyenv/versions/lib/python3.7/site-packages/django/core/servers/basehttp.py", line 50, in get_internal_wsgi_application
    ) from err
django.core.exceptions.ImproperlyConfigured: WSGI application 'fec.wsgi.application' could not be loaded; Error importing module.

[rfultz]

Some Wagtail / Django research:

We’re currently using Wagtail 2.7.4
‘Stable’ is 2.12
Most recent is 2.12.2

Of potential concern for editors:

• 2.11 starts Wagtail’s phase-out of supporting Internet Explorer 11.
• With 2.11, admins using IE will get a warning that they need to upgrade.
• With 2.12, all Wagtail users will get that warning.
• 2.13 will show a message on every page.
• 2.14 will not support IE11 at all.

I imagine this means only while logged in to Wagtail, right? Would be weird for Wagtail to show warnings to site visitors, too…

Wagtail 2.10

• started supporting Django 3.1
• no longer supports Python 3.5 (we’re using 3.7.9?)

Wagtail 2.9

• stopped supporting Django 2.1 (we’re using Django 2.2.16)

Django 3.0

• supports Python 3.6 to 3.9
• no longer supports Postgres 9.4

Django 3.1 didn’t change Python or Postgres support from Django 3.0

[rfultz]

Created a branch (feature/4384-wagtail-to-2.11) yesterday while working on #3804 but ran into issues during pytest with psycopg2:
psycopg2.errors.UndefinedColumn: column wagtailcore_page.locked_at does not exist so may spend another couple minutes investigating but will likely pin this until next sprint+

[rfultz]

Adding a point because of the database/migrations/psycopg2 complications