Exception thrown by 0074_drop_curated_thumbs when upgrading from 3.3.x to 4.x

[giohappy]

Migration 0074_drop_curated_thumbs threw the following exception while upgrading from 3.3.x demo to 4.x.

File "/usr/src/geonode_master/manage.py", line 31, in <module>
  execute_from_command_line(sys.argv)
File "/usr/local/lib/python3.10/site-packages/django/core/management/__init__.py", line 419, in execute_from_command_line
  utility.execute()
File "/usr/local/lib/python3.10/site-packages/django/core/management/__init__.py", line 413, in execute
  self.fetch_command(subcommand).run_from_argv(self.argv)
File "/usr/local/lib/python3.10/site-packages/django/core/management/base.py", line 354, in run_from_argv
  self.execute(*args, **cmd_options)
File "/usr/local/lib/python3.10/site-packages/django/core/management/base.py", line 398, in execute
  output = self.handle(*args, **options)
File "/usr/local/lib/python3.10/site-packages/django/core/management/base.py", line 89, in wrapped
  res = handle_func(*args, **kwargs)
File "/usr/local/lib/python3.10/site-packages/django/core/management/commands/migrate.py", line 244, in handle
  post_migrate_state = executor.migrate(
File "/usr/local/lib/python3.10/site-packages/django/db/migrations/executor.py", line 117, in migrate
  state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "/usr/local/lib/python3.10/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
  state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "/usr/local/lib/python3.10/site-packages/django/db/migrations/executor.py", line 227, in apply_migration
  state = migration.apply(state, schema_editor)
File "/usr/local/lib/python3.10/site-packages/django/db/migrations/migration.py", line 126, in apply
  operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "/usr/local/lib/python3.10/site-packages/django/db/migrations/operations/special.py", line 190, in database_forwards
  self.code(from_state.apps, schema_editor)
File "/usr/local/lib/python3.10/site-packages/geonode/base/migrations/0074_drop_curated_thumbs.py", line 26, in update_thumbnail_urls_and_delete_curated_thumbs_folder
  filename = _generate_thumbnail_name(resource.get_real_instance())
File "/usr/local/lib/python3.10/site-packages/polymorphic/models.py", line 173, in get_real_instance
  return real_model.objects.db_manager(self._state.db).get(pk=self.pk)
django4geonode_demo | AttributeError: 'NoneType' object has no attribute 'objects'

Testing the retrieval of the "real instance" models manually (shell script)) we get the following:

Real instance 'test map by admin' found for resource_id:78 - map
Real instance 'Adagio - Johann Sebastian Bach.mp3' found for resource_id:70 - document
No real instance found for resource_id:225 - geostory
Real instance 'remote file' found for resource_id:222 - document
Real instance 'new by admin' found for resource_id:228 - map
No real instance found for resource_id:221 - layer
No real instance found for resource_id:334 - layer
Real instance 'racconto.pdf' found for resource_id:338 - document

It looks like it fails retrieving the polymorphic types for geostory and layers.

[marthamareal]

@giohappy this happens because the resources polymorphic_ctype models are not changed yet. eg layer to dataset.

For a moment the issue is solved by running migrations for apps layers, geoapps, geonode_mapstore_client before running the above migration.

Also, there are some migrations from 4.x which are already applied in 3.3.x. these are skipped with --fake flag.
These migrations include:

base.0080_alter_resourcebase_uuid
upload.0034_uploadsizelimit
upload.0035_update_uploadsizelimit_objects
upload.0036_upload_store_spatial_files