How to connect to the Docker host from inside a Docker container?

As of Docker version 18.03, you can use the host.docker.internal hostname to connect to your Docker host from inside a Docker container. This works fine on Docker for Mac and Docker for Windows, but unfortunately, this is not was not supported on Linux until Docker 20.10.0was released in December 2020. Starting from version 20.10 , the Docker Engine now also supports communicating with the Docker

[hidehara]

Mac and Win と Linux で実装の差があるのね。ホストとの通信に関わる事項だから仕方がないかな。