In a Database Per Service model - should i include the database in the service container?
Keep the DB containers separate. The concept of microservices and containers is to allow each part to be independently updated without introducing changes and outages to the rest of the application stack. Containers should also be running a single app per container to allow error detection and log gathering from that application. Each container is simply an isolated process, so unlike a VM, there's little overhead on the host to split each of these out.