A nice base Vagrantfile for debian/jessie64 on Virtualbox.

Vagrantfile

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

# All Vagrant configuration is done below. The "2" in Vagrant.configure
# configures the configuration version (we support older styles for
# backwards compatibility). Please don't change it unless you know what
# you're doing.
Vagrant.configure(2) do |config|

  # Every Vagrant development environment requires a box. You can search for
  # boxes at https://atlas.hashicorp.com/search.
  config.vm.box = "ubuntu/trusty64"

  config.vm.provider "virtualbox" do |vb|
    vb.memory = 2048
    vb.cpus = 2
    vb.customize ["modifyvm", :id, "--natdnshostresolver1", "on"]
    vb.customize ["modifyvm", :id, "--natdnsproxy1", "on"]
  end

  # basic configuration
  config.vm.provision "shell", inline: <<-SHELL
    sudo apt-get update
    sudo apt-get upgrade -y
    sudo apt-get install -y \
      git \
      git-core \
      vim \
      build-essential \
      python-dev \
      libssl-dev \
      libncurses5-dev \
      ntp \
      haveged \
      unzip
  SHELL

end

I never remember the NAT DNS settings so I've created this gist! Without forwarding the NAT DNS resolver, the network in the VM is super slow.