Thank you!
I get:
$ sudo docker-compose logs nginx
Attaching to central_nginx_1
nginx_1 | WARNING: no logs are available with the 'local' log driver
even after I've tried browsing https://localhost/ again.
Oh, weird. Even though the DNS name works from nearby (e.g. for ssh), I actualy get a "connection refused" from, e.g. links myodkdomain.net
I'm happy to wait another 12 hours or so but not sure why localhost doesn't work. Or maybe https never works for localhost, since the certificate is not for localhost!?
In that case my symptom is the refusal to connect, since my server does seem to have the DNS for its own FQDN.