Connecting from Container to host
One problem I faced was to connect to the host from a container. (It was because of a live logging application)
I achieved the desired result by doing adding the extra_hosts section in my compose file:
With this I can call logserver.local
inside of my container and it gets routed to the localhost.
If you want to configure it so that host-gateway points to a specific IP address you can configure it in the /etc/docker/daemon.json
This can be especially useful if you install docker without docker-desktop on WSL. Then you can route your host-gateway to the virtual network-interface connecting to windows.