Virtual box port forwarding
Forward port 8080 to 80 on box docker-machine-vm
This should most likely be 8080 to 8080, but this is more clear what's going on.
VBoxManage controlvm docker-machine-vm natpf1 Forward_8080_to80,tcp,,8080,,80
… or in powershell due to the ~,~
VBoxManage controlvm docker-machine-vm natpf1 "Forward_8080_to80,tcp,,8080,,80"
Alternately, rtfm.