docker build -t testbigdockerlogs .
fleetctl start testbigdockerlogs.service
docker logs
shows the full message
fleetctl journal
chops messages into 2048 chunks
journalctl -u testbigdockerlogs.service
chops messages into 2048 chunks
https://github.com/stuart-warren/bigjournallogs
Using the github.com/coreos/go-systemd/journal golang library shows that the journal can handle large log lines.