using a config like:
journal:
brokers: - 127.0.0.1:29002
shoud allow to execute swh commands like swh storage replay or `swh
dataset export` from the host, consuming kafka topics from the
docker-compose.
Also configure kafka topics cleanup policy to 'compact'
instead of the default 'delete', so the user can keep its data in the
test kafka server for more than a week.