What is Vagrant? It’s a;
- A tool for developers, QA and IT people
- A virtual machine management tool
- Remove frictions on setting up development environment
- Remove frictions on reproducing errors and runtime anomalies due to machine configuration differences
For the full pep-talk, go to vagrantup.com/intro
Before we go any further, let’s have some definition of terms.
- vm what I mean by vm is both the virtualBox and vagrant. If I need to refer to either Vagrant or VirtualBox, I’ll use their respective names, but vm means virtualBox + vagrant
- host machine. The actual or physical PC. This could be your macOS, Windows or Linux PC
- guest machine. The vm
- box. is some sort of an operating system image. If you have performed complete disk backups of your operating system before, a box is similar to that. It is a snapshot of an operating system. Snapshots are taken and saved typically because you would like to restore them at a later time, either on the same hardware or a different one
Install Vagrant and VirtualBox
Vagrant requires requires either VirtualBox, VMWare or any other hypervisor virtualization. In our case, we’ll use VirtuaBox. The installation process is (a) install VirtualBox then (b) install Vagrant.
There are a couple of ways to install these software. It depends on your operating system and what kind of package manager you are using. macOS has HomeBrew and MacPorts, Linux has aptitude, rpm, yum etc. and Windows has chocolatey.
The most straightforward way is to install virtualbox and vagrant using pre-compiled binaries. The process involves nothing more than downloading these binaries, double-clicking them and following the wizards. Just like how you would install any other app in your system.
In this article, we won’t use the precompiled binaries. We’ll install vagrant using the package managers. Examples 1,2 and 3 shows how to install vagrant in macOS, Windows and Linux respectively.
Example 1. Installation on a macOS with brew
brew update brew tap caskroom/cask brew cask install vagrant brew cask install virtualbox
For Windows, you need to install chocolatey first, go here for instructions
Example 2. Installation on a Windows PC
cinst --y virtualbox vagrant
Example 3. Installation on Linux using apt-get
sudo apt-get update sudo apt-get upgrade sudo apt-get install vagrant virtualbox-dkms
Make sure everything has been installed properly. On terminal window, run the following commands
vagrant --v vboxmanage - v
If you saw the actual version numbers of vagrant and virtualbox instead of getting a “command not found” or “bad command or filename” error, that means virtualbox and vagrant are good to go.
Vagrant uses the term “box” to refer to an OS image. Before we can create a vagrant instance, we need to get a box. You can get boxes from vagrantup.com and many other places, but we’ll get ours from ubuntu.com. The command below downloads the ubuntu precise box to our workstation
$ vagrant box add ubuntu-precise http://cloud-images.ubuntu.com/precise/current/precise-server-cloudimg-vagrant-i386-disk1.box
Most of these boxes are 350 - 500mb in size. Grab a coffee if you have slow internet connection
A vagrant box is not the same as a vagrant project. Remember that a box is just an image of the operating system. You can create many projects using the same image. But we will need a box before we can create project.
You can use the ubuntu-precise box we downloaded earlier for multiple projects. This is actually one of the main use cases for vagrant. You can isolate the libraries and configurations of your projects. That way, you always have a clean baseline box.
To create our first project, we need to do (a) create a folder for our project (b) run
vagrant init inside the project folder and c) optionally, edit the vagrant file if we want to alter some of the default settings of vagrant
To create a project, follow the commands below.
$ mkdir -p ~/vms/myProjectName && cd ~/vms/myProjectName $ vagrant init ubuntu-precise
vagrant init will create a vagrant config file. This is what you can configure and eventually commit to source control.
Then we can start using the virtual machine
cd ~/vms/myProjectName vagrant up # starts the vm vagrant ssh # login to the vm
Other commands to manage vm
vagrant halt # like a shutdown vagrant suspend # puts the vm to sleep vagrant destroy # like halt, but also destroys the vm
Shared folder with host
There are many reasons to use vagrant. Some use it as test or staging server and some use it as a development server. When you use it as a development server, you need to have a way to share data between the host (the machine where you installed the vm) and the guest machine (the vm itself).
By default, Vagrant already shares the folder
/vagrant on the guest machine with the the folder
/vms/myProjectName (this is the directory where you created your vagrant project). If you want the guest and host machine to share files in folder other than the default (/vagrant), you need to configure that in Vagrantfile
When you longer need the OS image, you can delete the boxes in order to free up disk space. The physical location of the image files (boxes) are shown in Table 2.
Table 2. Location of boxes
+--------------------+-------------------------------+ | OS | Location of boxes | +--------------------+-------------------------------+ | Windows | %USERHOME%\.vagrant.d\boxes | | macOS or Linux | ~/.vagrant.d/boxes | +--------------------+-------------------------------+
To delete a box, do the following.
vagrant box list vagrant box remove <name of the box>
If you simply want to rename a box, you can do the following
vagrant box repackage
Vagrantfile is a configuration file. It was created when you issued the command
vagrant init. It’s written in the Ruby language, so it’ s very easy to read. There are a lot of defaults that are already defined in this config file. You simply need to uncomment them if you need to enable any particular functionality e.g. port forwarding etc. The Vagrantfile has a simple structure, everything is inside the
Vagrant configure block. See the code example below
Vagrant configure(2) do |config| # various configurations end
One of the common reasons why we run vagrant boxes is so that we can run server applications in them, either for testing or for development or something else. No matter what the reasons are why you setup vagrant, you will need a way to access the servers that are running on your guest machine. There are three ways to do this (1) setup your vm as a public network (2) set it up as private network and lastly (3) use port forwarding. Each of these options have their advantages and disadvantages. Your general security situation and project goals will largely determine which approach is right for you.
This is known as bridge networking. If you go for this setup, the guest computer, your vm, will actually appear as another node in the current network segment. It will appear as another computer in your network neighborhood. In a public network, you may be able to refer to your guest machine via its hostname because your DNS server might be able to pick up the hostname of the vm when the DHCP server gives it an IP address.
The Vagrantfile for a publicly accessible vm (with static IP) looks like the following
Vagrant.configure(2) do |config| config.vm.network "public_network", ip: "192.168.1.210" end
This type of configuration will boot up your machine and assign itself a static IP address of 192.168.1.210. It will appear as another node in the network segment
If you want to set up a public vm with dynamic IP, you can do it with the following Vagrantfile
Vagrant.configure(2) do |config| config.vm.network "public_network", type: "dhcp" end
In this type of configuration, the guest machine will act like it is another node of the network segment. It will listen to any DHCP broadcast, if it finds any, it will fetch an IP address from the server
Vagrant boxes are insecure out of the box. That’s why the public_network setting is commented by default. Think of it this way, a computer on a private network is usually behind a firewall and/or a router. Most computers on an office setting belong to this category. Your office workstation is not reachable from the internet because it is behind a firewall.
When you create a vagrant project, the vm is on a private network. That means you cannot reach any of its ports from the host machine, unless you define a public network. Having a vm that is not accessible from your host machine is not very useful, so we need a way to reach the applications running on the vm. One way to do it via port forwarding. Basically, we will map a port number on the host machine to a port of on the guest machine (your vm). That way, when we try to communicate to a port on the host machine, that request will be forwarded to the port of the guest machine, thus making the services of the guest machine reachable.
To enable port forwarding, you need to edit the Vagrantfile, and uncomment the following line (remove the # sign on the left)
config.vm.network "forwarded_port", guest:80, host:8080, id: "whatever"
This line has 4 parts. The first one is the name of the configuration, the 2nd, 3rd and 4th part are as follows
- guest:80. The vm will listen on port 80, this is usually a web server like Apache or NGinx or any other webserver that you want to use
- host:8080. This is the port on the host machine (your actual PC where the vagrant is installed). When you launch a browser and go to http://localhost:8080, you are actually hitting the port 80 of your vm
- id: whatever. This is optional, but it is always a good idea to to put an id on your port mapping definition
You can forward more than one port. If you need to open more ports on the guest machine, just define each mapping on separate lines, like this
config.vm.network "forwarded_port", guest:80, host:8080, id: "apache" config.vm.network "forwarded_port", guest:4000, host:3000, id: "node"