How to use this box with Vagrant:

Vagrant.configure("2") do |config|
  config.vm.box = "yungsang/coreos"
  config.vm.box_version = "0.7.2"
end

vagrant init yungsang/coreos \
  --box-version 0.7.2
vagrant up

This version was created about 10 years ago.

CoreOS

Based on CoreOS 291.0.0
Enable the Docker daemon
Support Docker provisioner
Add override-plugin.rb
Cf.) https://github.com/coreos/coreos-vagrant/blob/master/override-plugin.rb
Use btrfs for Docker as well
"One unfortunate side effect of this change is that all Docker containers will need to be reinitialized on CoreOS (docker pull, or docker build). "
Cf.) http://coreos.com/blog/new-filesystem-btrfs-cloud-config/
Use docker-tcp.socket to expose the port 4243
Cf.) http://coreos.com/docs/launching-containers/building/customizing-docker/#enable-the-remote-api-on-a-new-socket
Override cloud-config.yml to setup Docker and /etc/oem-release

$ vagrant init yungsang/coreos
$ vagrant up

1 provider for this version.

virtualbox
unknown	Externally hosted (github.com)

yungsang/coreos Vagrant box