Docker is just two files: docker.exe and dockerd.exe in “C:\Program Files\Docker” directory. You can replace them during the build:
1. Stop docker service
2. Download Docker files from edge channel and unpack to Docker directory.
3. Start docker service.
Is there a way to configure the Docker host to build Linux containers? It seems like the Docker host is configured to run Windows containers, which I think is actually a very small edge case at the moment as nobody really does that.