Vagrantfile for Fedora 31.

Vagrantfile

# -*- mode: ruby -*-
# vi: set ft=ruby :

Vagrant.configure("2") do |config|
  # https://app.vagrantup.com/fedora/boxes/30-cloud-base
  config.vm.box = 'fedora/30-cloud-base'
  config.vm.provider "virtualbox" do |vb|
    # 512 MB is too small to execute dnf command
    vb.memory = "1024"
  end

  # https://fedoraproject.org/wiki/DNF_system_upgrade
  #
  # Execute 'vagrant ssh -c "sudo dnf system-upgrade reboot"' after provisioning.
  # It will takes several minutes.
  config.vm.provision "shell", inline: <<-SHELL
    dnf upgrade --refresh -y
    dnf install dnf-plugin-system-upgrade -y
    dnf system-upgrade download --refresh --releasever=31 -y
  SHELL
end