Key auth for Vagrant VMs

key_authorization.rb

def authorize_key_for_root(config, *key_paths)
  [*key_paths, nil].each do |key_path|
    if key_path.nil?
      fail "Public key not found at following paths: #{key_paths.join(', ')}"
    end

    full_key_path = File.expand_path(key_path)

    if File.exists?(full_key_path)
      config.vm.provision 'file',
        run: 'once',
        source: full_key_path,
        destination: '/home/vagrant/root_pubkey'

      config.vm.provision 'shell',
        privileged: true,
        run: 'once',
        inline:
          "echo \"Creating /root/.ssh/authorized_keys with #{key_path}\" && " +
          'rm -f /root/.ssh/authorized_keys && ' +
          'if [ ! -d "/root/.ssh" ]; then mkdir /root/.ssh; fi &&' +
          'mv /home/vagrant/root_pubkey /root/.ssh/authorized_keys && ' +
          'chown root:root /root/.ssh/authorized_keys && ' +
          'chmod 600 /root/.ssh/authorized_keys && ' +
          'rm -f /home/vagrant/root_pubkey && ' +
          'echo "Done!"'
      break
    end
  end
end

Vagrantfile

require_relative '../vagrant/key_authorization'

Vagrant.configure('2') do |config|
  config.vm.box = 'ubuntu/trusty64'
  authorize_key_for_root config, '/home/mihail/.ssh/id_dsa.pub', '/home/mihail/.ssh/id_rsa.pub'
  {
    'db'    => '192.168.33.10',
    'elasticsearch'=> '192.168.33.11',
    'app'  => '192.168.33.12'
  }.each do |short_name, ip|
    config.vm.define short_name do |host|
      host.vm.network 'private_network', ip: ip
      host.vm.hostname = "#{short_name}.rc"
    end
  end
end

Thanks! This is very helpful, however I'd recommend using chef for provisioning of your virtual machines.