What makes a docker container not a "real machine"? Docker programs are running natively, just like any other program, without emulation/virtualization. Its not like a virtual machine (unless you're on one of the lesser operating systems like Windows or OSX), its just configuring some settings in the Linux kernel to isolate the process from other processes. Its basically just an enhanced chroot.
Because I would like to automate programs I use in Windows with files that I actually use, instead of some random linux docker container. I should have used my actual machine instead of a real machine.
