The absolute minimum you need to know about Vagrant

Joe · October 16 2013

Vagrant is a tool that allows the user to spawn, launch, halt and manage multiple Virtual Machines easily. It's a CLI to various backends (so far only Virtualbox and VMWare). Here’s a list of commands that would help any newcomer to Vagrant to be productive quickly. This is not meant to be exhaustive. For (a lot) more, check out the official documentation.

Boxes

Boxes are images Vagrant uses to create VMs. You can look for boxes online or pass them around on the network. From the doc:

Boxes are the skeleton from which Vagrant machines are constructed. They are portable files which can be used by others on any platform that runs Vagrant to bring up a working environment.

To add a box
You can find some boxes on Vagrantbox.es

$ vagrant box add mynewbox http://url/to/some/box

Or a box that you have locally

$ vagrant box add mynewbox /path/to/some/box

To list the existing boxes

$ vagrant box list

Vagrantfiles

A Vagrantfile describes the network of machines you are building. When executing a command, vagrant will look for a file named “Vagrantfile” in the current directory. You can learn how to write complex Vagrantfiles in the official documentation. Here’s the simplest example:

Init file

$ vagrant init
$ ls
Vagrantfile

This command has created a minimal Vagrantfile. Modify it so that it includes your selected box:

Vagrant.configure("2") do |config|
  config.vm.box = "base"
end

This configuration defines one machine based on the box "base" (the machine will be called “default”). It will use default values for everything else.

Machines status

$ vagrant status
Current VM states:

default                  not created

The environment has not yet been created. Run `vagrant up` to
create the environment.

Other statuses include:

poweroff
running

Status is particularly useful when you have several machines in a Vagrantfile.

Install and run

$ vagrant up
$ vagrant status
Current VM states:

default                  running
 This command will start the VM. If the VM hasn’t been created or has been destroyed, it will first install the OS on the machine.

Connect to the machine

$ vagrant ssh

ssh is activated by default.

Username: vagrant
Password: vagrant
sudo: enabled

File sharing

By default, Vagrant automatically maps the current directory to the /vagrant directory in the guest machine. Files are instantly synchronized.

Halt a machine

$ vagrant halt

Use this command to put a machine in the ‘poweroff’ status. It will boot into the exact same state next time you run ‘vagrant up’

Destroy a machine

$ vagrant destroy

This command will completely destroy the machine.

Multiple machines

Vagrantfiles
It is possible to define more than one machine in a Vagrantfile. Like this:

Vagrant.configure("2") do |env_config|
    env_config.vm.define "db1" do |config|
        config.vm.box = "ub1204_64"
        config.vm.network :private_network, ip: "192.168.1.1"
    end
    env_config.vm.define "db2" do |config|
        config.vm.box = "ub1204_64"
        config.vm.network :private_network, ip: "192.168.1.2"
    end
    env_config.vm.define "webserver" do |config|
    config.vm.box = "ub1204_64_firewalled"
    config.vm.network :private_network, ip: "192.168.2.0"
    end
end

vagrant commands

When you have more than one machine defined in your Vagrantfile, certain commands like “vagrant ssh” are ambiguous. Two things to keep in mind:

Append one or more machine names

$ vagrant up db1 db2 webserver

No machine name will mean all (when applicable): “vagrant up” will execute for every machine defined, but “vagrant ssh” will throw an error.

Networking

10.0.2.15
By default, vagrant will create an interface eth0 in each machine and assign it IP 10.0.2.15. The virtual machine uses this interface for communication with vagrant. I find it easier to avoid using this interface for hosting my services.

Add an interface
Here’s how we can define an aditional interface on a machine:

Vagrant.configure("2") do |config|
  config.vm.box = "debian_wheezy"
  config.vm.network :hostonly, ip: "192.168.33.10"
end

This has defined a host-only interface. This is taken from the official Virtualbox documentation:

Host-only networking
This can be used to create a network containing the host and a set of virtual machines, without the need for the host’s physical network interface. Instead, a virtual network interface (similar to a loopback interface) is created on the host, providing connectivity among virtual machines and the host.

xterm · October 18 2013

Great quick intro rahmu. Thanks.

rolf · October 18 2013

Hello,
Thanks for the nice explanation.
Vagrant seems useful, I just have one comment, why the hell call an image a "box"... I mean there's already a word for it and it's "image"...

Joe · October 18 2013

Agreed. I cannot imagine why they wouldn't chose "image".

xterm · October 18 2013

I believe the term box is well in place. The word image already identifies many things relating to virtualization. There's already the virtual machine image and the ISO image. If you add to that a vagrant image, you can no longer say image without it being cryptic. However, box is unused and, just cool!.

Ayman · October 18 2013

I've been using Vagrant for a while now especially when
1. Confined to working on a Windows box and need a small Linux environment to build on
2. For creating isolated portable environments for different projects

Great post rahmu, I think you should have also mentioned port forwarding which is vital for accessing web apps from the host while the dev server running on Vagrant.

LebGeeks

#1 October 16 2013