The following have been added to the image (in addition to those listed in README.md):
- bzip2, dkms, gcc, perl, and VBoxGuestAdditions are installed
- Root password is set to root
To build a VirtualBox box:
rm -f /tmp/packer-centos-7.3.1611-x86_64-updates-vbox-*
packer build --only=vbox4vbox centos-7.3.1611-x86_64-updates.json
- Launch
/tmp/packer-centos-7.3.1611-x86_64-updates-vbox-*/*.vmdk
in VirtualBox - Smoke test (e.g., login via console and look around)