Docker container accesses host database service

  docker, question

After I used docker network create mynet,
When creating containers, they are all connected to this docker network (docker run –net mynet).
In this way, docker containers can access each other through hostname to avoid writing dead IP.

My doubt is,
On the docker host computer, a service is started and monitored on the intranet network card eth1 at
How can the container access this service of the host? Try to avoid writing dead IP?

The sink host runs IP-4addr showdock 0 | grep-po ‘inetk [d.]+’,which is the IP that the container can use to access the sink host;
Available from 18.03 onwardshost.docker.internal