Building Vagrant Base Boxes

In this page we will look at how to create Vagrant base boxes of any type and store them so that you can have multiple developers use them. This will be a step by step guide and i will build a CentOS 7 console and a Ubuntu 14.04 desktop VM. You will learn how to configure the system through VirtualBox and then create a Vagrantfile to allow others to deploy your base boxes.

Step 1
Download the versions of the operating systems you wish to use with Vagrant. You can use either the live ISOs or the full install media,  the difference being is that you have greater flexibility with the full install for creating minimal builds. The live ISOs may include to much.

NOTE: you can customise your base builds using a provisioning script as part of vagrant to add to your base boxes, so don't put too much on them to start with.

Your base box is exactly what it says, the core common components that everyone needs, which means you would have console only and/or GUI base boxes for each OS.

Downloads are obtainable for many ISO images from the main Linux distros.

- http://www.centos.org
- http://www.ubuntu.com
- http://www.linuxmint.com/
- http://www.slackware.com/
- https://access.redhat.com/downloads
- https://www.suse.com/
- http://www.opensuse.org/en/

Step 2
All users of your system will want to have the same virtual environment installed, in this one we will use VirtualBox,  and it is important to install the guest additions too (known as the extension pack on the download page).

- https://www.virtualbox.org/wiki/Downloads

Once you have VurtualBox installed go to File --> Preferences. Select Extensions, and add the extension pack. This will ensure that your VMs can make use of the vboxsf file system for mounting directories for running provision scripts and more, by Vagrant.

Step 3
Create your base VM in VirtualBox.

First let's create the base box for a CentOS console server build. For this we will install a minimal Linux build.

VM requirements
To build a CentOS host you will need the following minimal hardware requirements;
- 1024mb Ram
- make the virtual disk dynamic and the bigger the better. The VM will grow to use the space and will be small to start with.
NOTE: the disk should be VMDK this allows vagrant to make the disk available to different VM hosting software.
- cdrom iso image
- for a console you don't need much in the way of video ram so the default 12mb is sufficient
- attach the CentOS 7 iso to the cdrom
- the 1st network adapter should be NAT. All other NICs can be added in the Vagrantfile when building new VMs from the base box.

Once you have configured the VM hardware install the operating system.  In this case chose a minimal install for CentOS.

One key difference in the OS choice is whether ssh daemon is installed by default. You should ensure that ssh is available on the system either during or after installing.

Another difference is whether the C compiler and kernel headers are installed.  You should include these in the install so the guest additions can be installed.

During the install set root password as vagrant.
If you can add users during the install create a user called vagrant with password of vagrant.

Step 4
Preparing the VM for Vagrant requires some extra configuration.  In this step we will cover all necessary steps to configure the VM to be a bar box regardless of the OS.

Log in as root.

NOTE: on Debian type systems you may need to install dkms;
$ apt-get install -y dkms linux-kernel-headers
NOTE: on Red Hat type systems you may need kernel headers and development tools;
$ yum -y install kernel-headers
$ yum -y groupinstall "Development tools"

Update the system;
For Debian;
$ apt-get update -y
$ apt-get upgrade -y
For Red Hat;
$ yum -y update

Install guest additions.
Select Devices --> Install guest additions
In a console only VM this will insert the CD into the virtual drive, so you'll need to mount it;
$ mount /dev/cdrom /mnt
Run the VBoxLinuxAdittions.run command to install;
$ /mnt/VBoxLinuxAdittions.run

After installation is complete unmount and eject the cdrom;
$ umount /mnt
$ eject cdrom

Add the vagrant user if you were not able to during install;
$ useradd -m vagrant
$ passwd vagrant
Set the password to vagrant

Add the vagrant user to the /etc/sudoers file by adding the forewing line;
vagrant  ALL=(ALL)   NOPASSWD:   ALL

You will also need to comment the line the requires a tty to do sudo.
In /etc/sudoers make sure you have this line;
Default  requirestty
Change to;
#Default  requirestty

Add the ssh key for the vagrant user;
$ mkdir -p /home/vagrant/.ssh
$ curl -k https://raw.githubusercontent.com/mitchellh/vagrant/master/keys/vagrant.pub > /home/vagrant/.ssh/authorized_keys
# Ensure we have the correct permissions set
$ chmod 0700 /home/vagrant/.ssh
$ chmod 0600 /home/vagrant/.ssh/authorized_keys
$ chown -R vagrant /home/vagrant/.ssh

NOTE: here we have used the generic vagrant public key,  which means your users will need to configure their ssh to use the vagrant private key which is available from the same site that the wget command points to.
NOTE: you may also need to install wget, or curl for the above wget step.

You may need to install the ssh service.
On Debian based systems;
$ apt-get install -y openssh-server
On Red Hat systems;
$ yum -y install openssh

Edit the /etc/ssh/sshd_config file and ensure the following is set;
- Port 22
- PubKeyAuthentication yes
- AuthorizedKeysFile %h/.ssh/authorized_keys
- PermitEmptyPasswords no

Restart the sshd service;
$ service ssh restart

At this stage you can add any further software to this base build before we package it,  or extra software can be installed using vagrant.

Shut down the VM;
$ init 0

Step 5
Now we are ready to package the box. Using the vagrant commands.

$ vagrant package --base "Name of VirtualBix VM"
NOTE: replace "Name of VirtualBix VM" with the name of the VM shown in your VirtualBox list of VMs.

This will export the VM and turn it into a compressed package.box that vagrant understands.

You can then move the package.box to your Web server that hosts vagrant base boxesso that other users can use them.

Step 6
If you use a Web server to host your vagrant base boxes you can then create Vagrantfile environments.  For example;

Vagrant::Config.run do |config|
  config.vm.define :default_fail do |failconfig|
    # This is here to fail the config if all machines are started by mistake
    failconfig.vm.provision :shell, :path => 'FAIL: This box is invalid, use vagrant up BOXTYPE'
  end

  # Test build
  config.vm.define :testme do |testme|
    testme.vm.customize ["modifyvm", :id, "--name", "testme", "--memory", "1024"]
    testme.vm.network :hostonly, "33.33.33.54"
    testme.vm.host_name = "testme"
  end

  # GUI build
  config.vm.define :gui do |gui|
    gui.vm.customize ["modifyvm", :id, "--name", "gui", "--memory", "1024"]
    gui.vm.network :hostonly, "33.33.33.55"
    gui.vm.host_name = "gui"
    gui.vm.provision :shell, :path => 'bin/gui_profile.sh'
  end
 
  ###
  # General config
  ###
  config.ssh.timeout = 60
  config.vm.box     = "default.box"
  config.vm.box_url = "http://myvagrant.websrv.net/baseboxes/CentOS7_x86-64.box"
  config.ssh.username = "vagrant"
  config.ssh.private_key_path= "/home/user/.ssh/vagrant_id"
end

The above configuration builds a basic minimal install through the testme build which if the Vagrantfile is in your directory and you run;
vagrant up testme
Will build the minimal CentOS build.

The gui configuration will use the minimal build and then executes a shell script to install more software and configure the system further. You can use this method to run puppet or other orchestration tools.

The general configuration area specifies what would apply to any build unless you override,  e.g. If you want a different base box then you would add a vm.box_url to your vm define.

And finally
I haven't discussed the Web server build he as that silly requires the ability to list files,  so a simple web server where you can simply add the base box files.

Now you should go play.