Simple requirement:  When an anonymous user visits the website, I want it to default to a specific website/database so they don't have to choose the database before even seeing the site... which is a really bad experience, clearly.

However, I do want to have multiple databases that can be selected by users of Odoo when they log in (or are identified by the domain name used). 

I have tried setting the db_name in the configuration, which has no effect, other than to provide a default for module installations etc.

I have tried setting the dbfilter, as follows:

dbfilter=mydbname

 - This correctly selects the exact db, but hides all the others from the selector, and is not dynamic based on domain name, therefore I am really stuck with a single DB with this approach.

dbfilter=^%h$  (which is supposed to be the variable for the full host.domain.tld name)

 - This just does not work.  I have set my db name as:  domainname, domainname.tld (exactly as it appears in the browser) and domainname-tld (as per some tip in a community thread on this topic).  In every case, it asks me to create a new database. 

As I have a naked/bare domain (no www) I cannot use the %d variable, as this only provides the hostname part of the domain name.

I am using nginx and hosting odoo inside a docker container - the nginx proxy pass info set as such:

proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-Server $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass http://prod-odoo:8069/;

So, I assume I am passing the hostname correctly. 

There appears no other way to make this work, but suggestions welcome.

Can you confirm a) is this possible, b) have I got my configuration correct, or c) is this a bug?