Kiwi Backup restore fails with python errors - docker

Question

I export database json doing commands explained here:
http://kiwitcms.org/blog/atodorov/2018/07/30/how-to-backup-docker-volumes-for-kiwi-tcms/
I'm running latest version of Kiwi.
docker exec -it kiwi_web /bin/bash -c '/Kiwi/manage.py sqlflush | /Kiwi/manage.py dbshell'
2.cat database.json | docker exec -i kiwi_web /Kiwi/manage.py loaddata --format json -
and I get this error:
Traceback (most recent call last):
File "/venv/lib/python3.6/site-packages/django/db/models/options.py", line 564, in get_field
return self.fields_map[field_name]
KeyError: 'description'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/venv/lib/python3.6/site-packages/django/core/serializers/json.py", line 69, in Deserializer
yield from PythonDeserializer(objects, **options)
File "/venv/lib/python3.6/site-packages/django/core/serializers/python.py", line 116, in Deserializer
field = Model._meta.get_field(field_name)
File "/venv/lib/python3.6/site-packages/django/db/models/options.py", line 566, in get_field
sh-4.2$ cat database.json | ./manage.py loaddata --format json -
Traceback (most recent call last):
File "/venv/lib/python3.6/site-packages/django/db/models/options.py", line 564, in get_field
return self.fields_map[field_name]
KeyError: 'description'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/venv/lib/python3.6/site-packages/django/core/serializers/json.py", line 69, in Deserializer
yield from PythonDeserializer(objects, **options)
File "/venv/lib/python3.6/site-packages/django/core/serializers/python.py", line 116, in Deserializer
field = Model._meta.get_field(field_name)
File "/venv/lib/python3.6/site-packages/django/db/models/options.py", line 566, in get_field
raise FieldDoesNotExist("%s has no field named '%s'" % (self.object_name, field_name))
django.core.exceptions.FieldDoesNotExist: Classification has no field named 'description'
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "./manage.py", line 12, in <module>
execute_from_command_line(sys.argv)
File "/venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
utility.execute()
File "/venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/venv/lib/python3.6/site-packages/django/core/management/base.py", line 316, in run_from_argv
self.execute(*args, **cmd_options)
File "/venv/lib/python3.6/site-packages/django/core/management/base.py", line 353, in execute
output = self.handle(*args, **options)
File "/venv/lib/python3.6/site-packages/django/core/management/commands/loaddata.py", line 72, in handle
self.loaddata(fixture_labels)
File "/venv/lib/python3.6/site-packages/django/core/management/commands/loaddata.py", line 113, in loaddata
self.load_label(fixture_label)
File "/venv/lib/python3.6/site-packages/django/core/management/commands/loaddata.py", line 168, in load_label
for obj in objects:
File "/venv/lib/python3.6/site-packages/django/core/serializers/json.py", line 73, in Deserializer
raise DeserializationError() from exc
django.core.serializers.base.DeserializationError: Problem installing fixture '-':

Answer 1

In which version of Kiwi TCMS did you make your backup ?
It looks like backup is from an older version because 6.5 ships with migrations that remove Build.description and Classification.description fields!
I am not sure it is technically possible to handle this gracefully. Please file an issue on GitHub so we can investigate in more details and link back to this SO thread.
A work around for you will be to launch not the latest version of Kiwi TCMS but the version in which you made the backup. Then restore your data, upgrade to the latest version, run the migrations which will change DB schema and then backup again.
If you do not keep around your older docker image you will have to build it from source.