sudo visudo -f /etc/sudoers.d/vagrant

vagrant ALL=(ALL) NOPASSWD:ALL

mkdir -p /home/vagrant/.ssh
chmod 0700 /home/vagrant/.ssh
wget –no-check-certificate 

    https://raw.github.com/mitchellh/vagrant/master/keys/vagrant.pub 

    -O /home/vagrant/.ssh/authorized_keys
chmod 0600 /home/vagrant/.ssh/authorized_keys
chown -R vagrant /home/vagrant/.ssh

Ubuntu

Older training VMs use

sudo sed -i -re ’s/([a-z]{2}.)?archive.ubuntu.com|security.ubuntu.com/old-releases.ubuntu.com/g’ /etc/apt/sources.list

References

• Building a Vagrant Box from Start to Finish
• How to Install Software or Upgrade From an Old Unsupported Release (Ubuntu)