Version:

• listmonk: v4.0.0.
• OS: Ubuntu 22.04.5 LTS
• Docker: 24.0.7

Description of the bug and steps to reproduce:

1. Remove all containers and volumes based on current docker-compose.yml, which might be already existing
2. Download/Overwrite docker-compose.yml with wget https://github.com/knadh/listmonk/raw/master/docker-compose.yml
3. Edit the new docker-compose.yml
   • Comment the lines containing: LISTMONK_ADMIN_USER and LISTMONK_ADMIN_PASSWORD
   • In the database ports section: Change "- 5432:5432" to - "5432" to not expose the database port to the host (encountered errors here due to an already exposed port from another container)
4. Run docker pull to update needed images
5. Run docker compose up db to create a running postgres instance
6. Run docker-compose run --rm app ./listmonk --install to create new database
7. Run docker-compose up to start app instance
8. Open a web browser to <Server-IP>:9000 the dialog to create Super-Admin credentials should show up
9. Enter new e-mail, username and password
10. Click "Continue"
11. Here the URL changes to localhost:9000/admin/login instead of <Server-IP>:9000/admin/login which cannot work from a remote PC.

Edit
Added an Nginx reverse proxy to allow SSL and fully working DNS
Setting the forms action URL to <Server-DNS-Name>:9000/admin/login in Firefox web developer console allowed a login.
In order to correct the form's action host, change the Root URL under Settings -> Settings.
But even with reverse proxy, it only works with port 9000 in Root URL. My local DNS resolves to my local net IPs, that's why it is working here.

Update
My Root URL was still starting http://
With this, the login does not work, if the reverse proxy login originates from https.
Still, the redirect to localhost is a problem after fresh install when trying to configure from external PC.

Did anyone else encounter that localhost redirect problem? Is it possible to add a Root URL variable in docker-compose.yml or is there already a possibility to change it there for installation?
I am looking forward to use listmonk with keycloak multi-user access. That is the reason for the update to v4.0.0
Thanks for any help.