How to update VirtualBox Guest Additions with vagrant (updated to VirtualBox 5.1.24)

gistfile1.sh

# Use centos/7
$ vagrant init centos/7
$ vagrant up

# You should see a message like:
#  [default] The guest additions on this VM do not match the install version of
#  VirtualBox! This may cause things such as forwarded ports, shared
#  folders, and more to not work properly. If any of those things fail on
#  this machine, please update the guest additions and repackage the
#  box.
#
#  Guest Additions Version: 5.1.24
#  VirtualBox Version: 5.1.24
########################################################################################################
## ATTENTION:
## Make sure you use the version of Guest Additions that match your VirtualBox version
## When following this gist in the future, the version referenced above will be obsolete.

$ vagrant ssh
vagrantup:~$ sudo yum -y update
vagrantup:~$ cd /opt
# replacing the version so that you are forced to change it and use the correct one
vagrantup:~$ sudo wget -c http://download.virtualbox.org/virtualbox/4.2.8/VBoxGuestAdditions_x.y.z.iso \
                       -O VBoxGuestAdditions_x.y.z.iso
vagrantup:~$ sudo mount VBoxGuestAdditions_x.y.z.iso -o loop /mnt
vagrantup:~$ cd /mnt
vagrantup:~$ sudo sh VBoxLinuxAdditions.run --nox11
vagrantup:~$ cd /opt
vagrantup:~$ sudo rm *.iso
vagrantup:~$ sudo /etc/init.d/vboxadd setup
vagrantup:~$ sudo chkconfig --add vboxadd
vagrantup:~$ sudo chkconfig vboxadd on
vagrantup:~$ exit

# Now check that the Guest Additions work
$ vagrant halt
$ vagrant up

# Package the new VM
$ vagrant halt
$ vagrant package
$ mv package.box centos-x.y.box