This is a database which is starting up automatically in a container when the quarkus dev profile ist started up. You can read more about the behaviour and configuration of the dev-services here and here.
1. Database Access
Key
Value
Host
localhost
Port
5432
username
quarkus
password
quarkus
database
default
2. Configuration in the application.properties
quarkus.datasource.devservices.port=5432
This configuration is for fixing the port to 5432 otherwise it is randomly set. This way it is possible to connect from the outside.