Introduction

Vagrant by Hashi Corp is an extremely useful tool for building and configuring reproducible development environments. Vagrant enables this with the sharing of configuration files that are used to build exactly the same environment every time. This allows for collaborative development with less instances of "it worked on my <insert dev machine>" bugs making it into production.

Architecture

vagrant architecture

Vagrant runs on your local machine and works in conjunction with Virtualbox, VMware Fusion or VMware Workstation. The following components make up the Vagrant architecture:

  • Atlas Hashicorp's hosted box repository
  • Vagrant Manages build environments
  • Vagrantfile Describes build environment
  • Hypervisor Host virtual machines

Boxes

Virtual machines in a Vagrant environment are called boxes. Hashicorp has an online repository for box hosting at https://atlas.hashicorp.com/boxes/. No account is needed to search for and download boxes which can be accessed at https://atlas.hashicorp.com/boxes/search. Note: It is also possible to host a private box repository on premise or in your own cloud.

centos/7 and ubuntu/trusty64 are examples of boxes available on Atlas.

Vagrantfile

A Vagrantfile is the mechanism used to define a build environment. When vagrant is instructed to start a build it will look for a file called Vagrantfile in the directory the build was initiated from.

Vagrant

The piece that ties it all together is Vagrant. You could say Vagrant is an orchastration engine for building development evironments. With only two commands you can have a box or boxes downloaded from Atlas and an entire environment provisioned in your hypervisor of choice.

Installation

Both Vagrant and Virtualbox can be installed on Windows, Mac and Linux. The installation process is very straight forward and outlined below.

Vagrant

Go over to https://www.vagrantup.com/docs/installation/ and download the installer for your operating system. I am using a Mac and the installation processs was as simple as opening the .dmg and following the prompts.


# check vagrant version
vagrant --version

# output
Vagrant 1.8.6
          
Virtualbox

Next head to https://www.virtualbox.org/wiki/Downloads and download the installer for your operating system. Similar to the Vagrant install, open the .dmg and follow the prompts.


# check virtualbox version
vboxmanage --version

# output
5.1.18r114002
          

Vagrant Command

Once Vagrant is installed all Vagrant related commands start with vagrant. To see a list of all available commands issue the vagrant list-commands command.


vagrant list-commands

# output
Below is a listing of all available Vagrant commands and a brief
description of what they do.

box             manages boxes: installation, removal, etc.
cap             checks and executes capability
connect         connect to a remotely shared Vagrant environment
destroy         stops and deletes all traces of the vagrant machine
docker-exec     attach to an already-running docker container
docker-logs     outputs the logs from the Docker container
docker-run      run a one-off command in the context of a container
global-status   outputs status Vagrant environments for this user
halt            stops the vagrant machine
help            shows the help for a subcommand
init            initializes a new Vagrant environment by creating a Vagrantfile
list-commands   outputs all available Vagrant subcommands, even non-primary ones
login           log in to HashiCorp's Atlas
package         packages a running vagrant environment into a box
plugin          manages plugins: install, uninstall, update, etc.
port            displays information about guest port mappings
powershell      connects to machine via powershell remoting
provider        show provider for this environment
provision       provisions the vagrant machine
push            deploys code in this environment to a configured destination
rdp             connects to machine via RDP
reload          restarts vagrant machine, loads new Vagrantfile configuration
resume          resume a suspended vagrant machine
rsync           syncs rsync synced folders to remote machine
rsync-auto      syncs rsync synced folders automatically when files change
share           share your Vagrant environment with anyone in the world
snapshot        manages snapshots: saving, restoring, etc.
ssh             connects to machine via SSH
ssh-config      outputs OpenSSH valid configuration to connect to the machine
status          outputs status of the vagrant machine
suspend         suspends the machine
up              starts and provisions the vagrant environment
version         prints current and latest Vagrant version
          

Getting Boxes

It is possible to get a vagrant box prior to initialising a build and also at build initialisation.

Prior To Initialisation

vagrant box add centos/7 --provider virtualbox
          

Downloading boxes prior to initialisation is useful if you want to build an environment in places you don't have any internet access. In the above example centos/7 is the box OS and virtualbox is the type of virtual machine.

At Initialisation

vagrant init centos/7; vagrant up --provider virtualbox
          

This will download the latest centos/7 box if not already downloaded. If the box was previously downloaded and still exists then it will not be downloaded again. Again, the virtual machine will be of the virtualbox type. These commands also initialise and bring up a build environment, there will be more on this later.

Once boxes are downloaded they are stored in ~/.vagrant.d/boxes/. To list all boxes issue the vagrant box list command.


vagrant box list

# output
CumulusCommunity/cumulus-vx (virtualbox, 3.2.1)
arista-vEOS                 (virtualbox, 4.15.9)
arista-vEOS                 (virtualbox, 4.18.0)
centos/7                    (virtualbox, 1608.01)
centos/7                    (virtualbox, 1702.01)
centos/7                    (vmware_fusion, 1702.01)
hashicorp/precise64         (virtualbox, 1.1.0)
juniper/vqfx10k-pfe         (virtualbox, 0.1.0)
juniper/vqfx10k-re          (virtualbox, 0.1.0)
          

Lab Environment

In this lab we will use Vagrant to download, build and delete an environment with a Centos host. I will be running this lab on my Macbook pro laptop and use Virtualbox as the hypervisor. This should be repeatable on either Linux or Windows with little to no modifications required.

vagrant build 1
Code versions used for this lab
  • OSX El Capitan - 10.11.6
  • Vagrant - 1.8.6
  • Virtualbox - 5.1.18
  • Centos/7 - 1702.01

Environment Build

At this point you should have Vagrant and Virtualbox installed, if not scroll back up and go through the installation process for both. You may or may not already have a centos/7 box installed. If not that is fine, we will download one as part of the build process.

Execute the following to start the build process.


# Make and change to build directory
mkdir -p ~/vagrant/test-build; cd ~/vagrant/test-build

# Initialise build environment
vagrant init centos/7; vagrant up --provider virtualbox
          

This will build a Centos 7 VM in virtual box and the output be similar to the below.


# output
A `Vagrantfile` has been placed in this directory. You are now
ready to `vagrant up` your first virtual environment! Please read
the comments in the Vagrantfile as well as documentation on
`vagrantup.com` for more information on using Vagrant.
Bringing machine 'default' up with 'virtualbox' provider...
==> default: Importing base box 'centos/7'...
==> default: Matching MAC address for NAT networking...
==> default: Checking if box 'centos/7' is up to date...
==> default: Setting the name of the VM: test-build_default_1490407027239_29074
==> default: Clearing any previously set network interfaces...
==> default: Preparing network interfaces based on configuration...
    default: Adapter 1: nat
==> default: Forwarding ports...
    default: 22 (guest) => 2222 (host) (adapter 1)
==> default: Booting VM...
==> default: Waiting for machine to boot. This may take a few minutes...
    default: SSH address: 127.0.0.1:2222
    default: SSH username: vagrant
    default: SSH auth method: private key
    default:
    default: Vagrant insecure key detected. Vagrant will automatically replace
    default: this with a newly generated keypair for better security.
    default:
    default: Inserting generated public key within guest...
    default: Removing insecure key from the guest if it's present...
    default: Key inserted! Disconnecting and reconnecting using new SSH key...
==> default: Machine booted and ready!
==> default: Checking for guest additions in VM...
    default: No guest additions were detected on the base box for this VM! Guest
    default: additions are required for forwarded ports, shared folders, host only
    default: networking, and more. If SSH fails on this machine, please install
    default: the guest additions and repackage the box to continue.
    default:
    default: This is not an error message; everything may continue to work properly,
    default: in which case you may ignore this message.
==> default: Rsyncing folder: /Users/brad/vagrant/test-build/ => /vagrant
          

.... and that is it, incredible right! So what exactly happened as part of this build? Lets have a closer look.

Vagrant Init

vagrant init centos/7 creates a Vagrantfile which is the configuration file describing the build environment.

Vagrantfile

# -*- mode: ruby -*-
# vi: set ft=ruby :

# All Vagrant configuration is done below. The "2" in Vagrant.configure
# configures the configuration version (we support older styles for
# backwards compatibility). Please don't change it unless you know what
# you're doing.
Vagrant.configure("2") do |config|
  # The most common configuration options are documented and commented below.
  # For a complete reference, please see the online documentation at
  # https://docs.vagrantup.com.

  # Every Vagrant development environment requires a box. You can search for
  # boxes at https://atlas.hashicorp.com/search.
  config.vm.box = "centos/7"

  # Disable automatic box update checking. If you disable this, then
  # boxes will only be checked for updates when the user runs
  # `vagrant box outdated`. This is not recommended.
  # config.vm.box_check_update = false

  # Create a forwarded port mapping which allows access to a specific port
  # within the machine from a port on the host machine. In the example below,
  # accessing "localhost:8080" will access port 80 on the guest machine.
  # config.vm.network "forwarded_port", guest: 80, host: 8080

  # Create a private network, which allows host-only access to the machine
  # using a specific IP.
  # config.vm.network "private_network", ip: "192.168.33.10"

  # Create a public network, which generally matched to bridged network.
  # Bridged networks make the machine appear as another physical device on
  # your network.
  # config.vm.network "public_network"

  # Share an additional folder to the guest VM. The first argument is
  # the path on the host to the actual folder. The second argument is
  # the path on the guest to mount the folder. And the optional third
  # argument is a set of non-required options.
  # config.vm.synced_folder "../data", "/vagrant_data"

  # Provider-specific configuration so you can fine-tune various
  # backing providers for Vagrant. These expose provider-specific options.
  # Example for VirtualBox:
  #
  # config.vm.provider "virtualbox" do |vb|
  #   # Display the VirtualBox GUI when booting the machine
  #   vb.gui = true
  #
  #   # Customize the amount of memory on the VM:
  #   vb.memory = "1024"
  # end
  #
  # View the documentation for the provider you are using for more
  # information on available options.

  # Define a Vagrant Push strategy for pushing to Atlas. Other push strategies
  # such as FTP and Heroku are also available. See the documentation at
  # https://docs.vagrantup.com/v2/push/atlas.html for more information.
  # config.push.define "atlas" do |push|
  #   push.app = "YOUR_ATLAS_USERNAME/YOUR_APPLICATION_NAME"
  # end

  # Enable provisioning with a shell script. Additional provisioners such as
  # Puppet, Chef, Ansible, Salt, and Docker are also available. Please see the
  # documentation for more information about their specific syntax and use.
  # config.vm.provision "shell", inline: <<-SHELL
  #   apt-get update
  #   apt-get install -y apache2
  # SHELL
end
          

As you can see most of the configuration is commented (#) out. When the vagrant init command is executed, Vagrant creates a default Vagrantfile in the current directory. The Vagranfile contains the most common settings, but the only configuration that will be executed is config.vm.box = "centos/7".

Vagrant Up

vagrant up --provider virtualbox starts the build process specifying virtualbox as the hypervisor. If the VM(s) specified in the Vagrantfile do not already exist on the local machine, they will be downloaded prior the the environment build.

As part of the machine build Vagrant also does the following:

  • Creates a port forward between the host machine and the VM for the SSH port 22.
  • Adds an SSH key to the VM to enable password less login.
  • Sets up a shared folder between the VM and the host machines local directory for easy file sharing.

Accessing Hosts

Accessing hosts is as simple as executing the vagrant ssh command. This will ssh from the host machine to the VM using the vagrant user. If you have more than one host configured in your Vagrantfile then also specify the hostname like so vagrant ssh <hostname>.


vagrant ssh

# You are now in the VM
[vagrant@localhost ~]$
[vagrant@localhost ~]$ whoami
vagrant
          

Stopping an Environment

If you want to stop and environment and come back to it later without having to go through the build process again issue the vagrant halt command.


vagrant halt

# output
==> default: Attempting graceful shutdown of VM...
          

Environment Status

To check the status of the environment issue the vagrant status command.


vagrant status

# output
Current machine states:

default                   poweroff (virtualbox)

The VM is powered off. To restart the VM, simply run `vagrant up`
          

Deleting an Environment

When you are finished with the environment issue the vagrant destroy command. This will halt and delete the VMs but the Vagrantfile will still be available.


vagrant destroy

# output
    default: Are you sure you want to destroy the 'default' VM? [y/N] y
==> default: Forcing shutdown of VM...
==> default: Destroying VM and associated drives...
          

Summary

So thats it, as part of this lab we downloaded and installed Vagrant and Virtualbox, used Vagrant to download virtual machines from Atlas, initialise and build an environment, access the VM from the host and delete the environment.

Remember: This is not the end, but merely the beginning!

The "from the start to the beginning" series aims to take you from nothing to getting you up and running. This is not meant to be a comprehensive guide, but should be enough to get you going on the journey.

Links

https://www.vagrantup.com/
https://www.vagrantup.com/docs/
https://atlas.hashicorp.com/boxes/
https://www.virtualbox.org/






















Published: 2017-03-25