Vagrant Presentation

This is the accompanying text to the Vagrant presentation available in this repository with comprehensive and structured information featured on the slides.

Vagrant (http://vagrantup.com) is a program for setting up reproducible and portable development environments easily with a large community.

Note: This presentation and text talks primarily about using Vagrant with libvirt provider provided by vagrant-libvirt plugin on Fedora and derivates. A lot of the information is general though.

Presenters

• Josef Stříbný
  • GitHub: @strzibny
  • Twitter: @strzibnyj
  • Blog: Notes to self

Josef does mostly Ruby and RubyGems packaging for Fedora and RHEL, and started to maintain Vagrant in Fedora.

Agenda

• The Goal ∧ Vagrant
• Vagrant components ecosystem
• Using Vagrant as a developer
• Creating your own box
• Finding Vagrant boxes
• Vagrant in Fedora
• Demo

The Goal

The goal is to have isolated, distributable and portable development environments.

• Isolated so your project's setup does not mess up with your workstation or other projects
• Distributable so new member of your team can just clone your project with Vagrantfile and get the project running easily by reusing the configuration
• Portable so you can run your project's development environment on Linux, Windows or Mac OS

Vagrant World

Vagrant is built around hosts, guests, providers and provisioners. Images are distributed in a provider-specific .box files and project's configuration is saved within Vagrantfile.

Definitions

Host

• Host operating system (Windows, RHEL), its detection and capabilities (NFS)

Many included by defaults, others by plugins.

Guest

• Guest operating system (Ubuntu, OpenBSD, Fedora), its detection and capabilities (halt, insert public key), virtualized environment

Many included by defaults, others by plugins.

Provider

• Provider of virtual machines or containers used (VirtualBox, libvirt, docker)

VirtualBox is upstream default and docker support is also included by default. libvirt and others are available via plugins.

Provisioner

• Configuration management system to set up (provision) your machine (Shell, Chef, Puppet, Ansible)

Shell, Chef and Puppet are included in Vagrant by default.

Vagrant box

• Package format including provider-specific image plus metadata

Vagrantfile

• Definition of configuration and provisioning for a project on top of a given box

Using Vagrant as a Developer

The simplicity behind Vagrant is that developer can checked out a project repository and -- provided it includes Vagrantfile -- just run vagrant up to provision the machine and to have a shared folder(s) of the project's source code and ports available so the development would feel pretty much like a local one.

With vagrant rsync-auto one can keep auto-syncing the shared folders (if synced via rsync) and with vagrant ssh one can access the machine via SSH. Once the work is finished, one can halt the machine with vagrant halt or destroy it with vagrant destroy.

$ ls ~/project
... ... ... Vagrantfile
$ vagrant up # start and provision VMs defined in Vagrantfile
$ vagrant rsync-auto
$ vagrant ssh

$ vagrant halt
$ vagrant destroy

Creating a Vagrant Box

From Scratch

Preparing the Image

To create a desired image for your Vagrant box you need to ensure that vagrant user with sudo rights and without password protection exists.

Vagrant will use this vagrant user to access your virtual machine via SSH which means that SSH has to be present in the virtual machine and properly set up.

To do so on CentOS 6, one has to install openssh-server package, start and enable the service first:

# yum install openssh-server
# service sshd start
# chkconfig sshd on
# netstat -tulpn | grep :22

For Fedora 21 Server is this already done by default so this step can be skipped.

Vagrant uses SSH keys to access the virtual machine so the public keys needs to be present on the VM for vagrant user.

You can set them easily with the following commands for vagrant user:

$ mkdir .ssh
$ curl -k https://raw.github.com/mitchellh/vagrant/master/keys/vagrant.pub
> .ssh/authorized_keys
$ chmod 0700 .ssh
$ chmod 0600 .ssh/authorized_keys

Since Vagrant would do system provisioning and administration, it needs to have sudo access on the machine. Using visudo command on Fedora you can edit sudoers file and ensure that vagrant won't need a password and have sudo rights with %vagrant ALL=(ALL) NOPASSWD: ALL.

When editing the sudoers file make sure that requiretty option is not present (or it is commented out). That is the default on Fedora. If you would require a real TTY then Vagrant commands sent to the VM would fail.

Last option to set up when in sudoers file is to allow SSH agent forwarding. You can set that up if you want to use the SSH key from our local machine inside the Vagrant box.

# No password
%vagrant ALL=(ALL) NOPASSWD: ALL
...
# No requiretty, Fedora default
# Defaults    requiretty
...
# SSH agent forwarding
Defaults env_keep += "SSH_AUTH_SOCK"

A good practice is also setting up root user with password "vagrant", although it is not necessary for Vagrant to work. Finally you can add anything you like to the VM. If you would like to do provision with Chef or Puppet for example, you would need to install them at this time. But if you would like to have installed Ruby, you can decide whether to include Ruby in the VM itself or include the installation later in the Vagrantfile.

Packaging VM as Box

Vagrant boxes are simply said just tarred images. What is important to note is that .box files are provider specific. Below is an libvirt example for which you need only the KVM image named as box.img and metadata.json file which specifies the provider.

Example: vagrant-libvirt provider and Fedora 21 server:

• qcow2 image file named box.img
• optional Vagrantfile with defaults
• metadata.json

The contents of the metadata file:

$ cat metadata.json
{
  "provider" : "libvirt",
  "format" : "qcow2",
  "virtual_size" : 40
}

Virtual size has to be set for allocating space in storage pool (in GB).

Once you have that prepared, you can just pack it all together using tar:

$ tar cvzf vagrant-fedora-21-server.box ./metadata.json vagrant-fedora-21-server.qcow2

In an Automatic Fashion

You can use a popular Ruby gem veewee to build your Vagrant boxes. It provides a lot of templates for various providers and guests.

Here is how to find and build a CentOS box with libvirt provider:

$ gem install veewee
$ veewee kvm templates # list available templates for KVM
$ veewee kvm define centos7-x86_64 'CentOS-7.0-1406-x86_64-netinstall' -f
$ veewee kvm build 'centos7-x86_64' --workdir=/home/strzibny

That box already comes with Puppet and Chef preinstalled as you can see for yourself by examing the template:

$ ls veewee/templates/CentOS-7.0-1406-x86_64-netinstall/
base.sh
chef.sh
cleanup.sh
definition.rb
ks.cfg
puppet.sh
vagrant.sh
virtualbox.sh
vmfusion.sh
zerodisk.sh

Template is just a collection of shell scripts that are run on the base VM to set it up for use as Vagrant box. definition.rb is an internal veewee definition for the box to be set up.

Finding Vagrant Boxes

Originally there was an official Vagrant Cloud (vagrantcloud.com) service that is being merged into a new service called Atlas (atlas.hashicorp.com).

With Atlas it's enough to:

vagrant up chef/centos-6.5 --provider virtualbox

and the corresponding box will be downloaded from HashiCorp servers.

A good unofficial alternative is http://www.vagrantbox.es/. You can add boxes from a given URL:

$ vagrant box add {title} {url}
$ vagrant init {title}
$ vagrant up

or add them with vagrant box add command.

Getting started using vagrant-libvirt

Let's get a box first and add it:

wget http://file.rdu.redhat.com/~jshubin/vagrant/fedora-21/fedora-21.box
vagrant box add fedora21 fedora-21.box

or:

vagrant box add fedora21 http://file.rdu.redhat.com/~jshubin/vagrant/fedora-21/fedora-21.box

Either action will add boxes in .vagrant.d/boxes:

$ ls .vagrant.d/boxes
fedora21/

To check:

$ vagrant box list
fedora21 (libvirt, 0)
rhel6    (libvirt, 0)

And to create Vagrantfile:

$ vagrant init fedora21

fedora21 either exists in .vagrant.d/boxes or box_url option is stated in Vagrant file:

config.vm.box = "fedora21"
config.vm.box_url = "http://file.rdu.redhat.com/~jshubin/vagrant/fedora-21/fedora-21.box"

$ vagrant up

$ vagrant up

==> default: Uploading base box image as volume into libvirt storage...
==> default: Creating image (snapshot of base box volume).

$ sudo ls /var/lib/libvirt/images
fedora21_vagrant_box_image.img


==> default: Creating domain with the following settings...
..
==> default:  -- Image:             /var/lib/libvirt/images/user_default.img

user is the current directory (/home/user) and default is the name of the VM, .img file is renamed image from the .box file.

==> default: Starting domain.
==> default: Waiting for domain to get an IP address...

libvirt uses dnsmasq program (DNS and DHCP server) which is automatically configured and started by libvirt for each virtual network switch.

Other actions follows including replacing insecure key-pairs and executing plugin hooks.

To see all our running VMs and containers:

$ vagrant global-status

Vagrant in Fedora

Vagrant in Fedora 22, 21

Vagrant has been submitted as a Fedora 22 feature together with vagrant-libvirt plugin. As Vagrant is already built for Fedora 22 in the official repositories it is enough to run:

# dnf install vagrant-libvirt

to install Vagrant with libvirt support. libvirt is the new default provider in Fedora builds.

I would like to introduce a new @vagrant group in Fedora as well.

Older Fedoras and RHEL

Following Copr repositories were created to install Vagrant on Fedora 20, 21 and as a software collection on RHEL.

• jstribny/vagrant-f20
• jstribny/vagrant-f21
• jstribny/vagrant1 software collection

Official RPM

It is also possible to run the official RPM from https://www.vagrantup.com/downloads.html which comes with VirtualBox provider as a default. You will still need to download and install VirtualBox yourself.

If you would like to use libvirt provider with the upstream package, you need to install vagrant-libvirt plugin with:

$ vagrant plugin install vagrant-libvirt

Demo

New demos for this tech talk:

• github.com/strzibny/vagrant-demo-rails-postgresql-passenger
• github.com/strzibny/vagrant-docker-examples

Please see demo/ folder for some more examples.

Attributions

• This presentation @ Josef Stříbný
• Vagrant logos and artwork @ HashiCorp, Inc.
• Fedora, libvirt logos @ Red Hat, Inc.
• Puppet logo @ Puppet Labs