Sharing a common development environment with everyone on your team is important. It is really hard though to keep the same dependencies, database versions and other systems in sync between different machines.

Vagrant is a great tool that helps with this and manage the lifecycle of a virtual machine. As nice as Vagrant is, provisioning machines with it has always been a pain. A couple of months ago Mitchell Hashimoto, the creator of Vagrant, launched Packer.

Packer lets you build Virtual Machine Images for different providers from one json file. You can use the same file and commands to build an image on AWS, Digital Ocean or for virtualbox and vagrant. This makes it possible to use exactly the same system for development which you then create in production.

In this blog post we will show you how you can use Packer to build your vagrant machines. In a follow up post we will focus on how we use Packer for building all of our Continuous Deployment Infrastructure.

Prerequisites for building Vagrant Machines

You need Virtualbox and Packer installed. Virtualbox provides packages for different Operating systems. Packer is even easier, just download the right zip for your system and unzip it into your PATH

Building your Virtual Machine with Packer

We’ve collected all the files necessary to build a Vagrant Machine with Packer in our Packer Example repository.

Packer uses builders, provisioners and post-processors as the main configuraition attributes. A builder can for example be virtualbox or AWS. A provisioner can be used to run different scripts. Post-processors can be run after the machine image is done. For example converting a Virtualbox image into a suitable image for vagrant is done in a post-processor.

Here is the main packer.json file. You can see the builder, provisioner and post-processor defined:

{
  "provisioners": [
    {
      "type": "shell",
      "scripts": [
        "scripts/root_setup.sh"
      ],
      "override": {
        "virtualbox": {
          "execute_command": "echo 'vagrant' | sudo -S sh '{{ .Path }}'"
        }
      }
    },
    {
      "type": "shell",
      "scripts": [
        "scripts/setup.sh"
      ]
    }
  ],
  "builders": [
    {
      "type": "virtualbox",
      "boot_command": [
        "<esc><esc><enter><wait>",
        "/install/vmlinuz noapic preseed/url=http://{{ .HTTPIP }}:{{ .HTTPPort }}/preseed.cfg <wait>",
        "debian-installer=en_US auto locale=en_US kbd-chooser/method=us <wait>",
        "hostname={{ .Name }} <wait>",
        "fb=false debconf/frontend=noninteractive <wait>",
        "keyboard-configuration/modelcode=SKIP keyboard-configuration/layout=USA keyboard-configuration/variant=USA console-setup/ask_detect=false <wait>",
        "initrd=/install/initrd.gz -- <enter><wait>"
      ],
      "boot_wait": "4s",
      "guest_os_type": "Ubuntu_64",
      "http_directory": "http",
      "iso_checksum": "4d1a8b720cdd14b76ed9410c63a00d0e",
      "iso_checksum_type": "md5",
      "iso_url": "http://releases.ubuntu.com/13.10/ubuntu-13.10-server-amd64.iso",
      "ssh_username": "vagrant",
      "ssh_password": "vagrant",
      "ssh_port": 22,
      "ssh_wait_timeout": "10000s",
      "shutdown_command": "echo 'shutdown -P now' > shutdown.sh; echo 'vagrant'|sudo -S sh 'shutdown.sh'",
      "guest_additions_path": "VBoxGuestAdditions_{{.Version}}.iso",
      "headless": false,
      "virtualbox_version_file": ".vbox_version",
      "vboxmanage": [
        [
          "modifyvm",
          "{{.Name}}",
          "--memory",
          "2048"
        ],
        [
          "modifyvm",
          "{{.Name}}",
          "--cpus",
          "4"
        ]
      ]
    }
  ],
  "post-processors": ["vagrant"]
}

It builds for virtualbox and then exports it into vagrant. The http folder contains a preseed.cfg file that is necessary to set up Ubuntu.

In the scripts folder you can find a root_setup.sh and setup.sh scripts.

The root_setup.sh script sets up necessary packages and parameters for Vagrant:

#!/bin/bash

set -e

# Updating and Upgrading dependencies
sudo apt-get update -y -qq > /dev/null
sudo apt-get upgrade -y -qq > /dev/null

# Install necessary libraries for guest additions and Vagrant NFS Share
sudo apt-get -y -q install linux-headers-$(uname -r) build-essential dkms nfs-common

# Install necessary dependencies
sudo apt-get -y -q install curl wget git tmux firefox xvfb vim

# Setup sudo to allow no-password sudo for "admin"
groupadd -r admin
usermod -a -G admin vagrant
cp /etc/sudoers /etc/sudoers.orig
sed -i -e '/Defaults\s\+env_reset/a Defaults\texempt_group=admin' /etc/sudoers
sed -i -e 's/%admin ALL=(ALL) ALL/%admin ALL=NOPASSWD:ALL/g' /etc/sudoers

#Install Redis
sudo apt-get -y -q install libjemalloc1
wget -q http://d7jrzzvab3wte.cloudfront.net/checkbot/deb/redis-server_2.6.13-1_a...
sha1sum redis-server_2.6.13-1_amd64.deb | grep 'ab50cf037fd63e160946f8946b6d318cdf11800d'
dpkg -i redis-server_2.6.13-1_amd64.deb
rm redis-server_2.6.13-1_amd64.deb

# Install required libraries for RVM and Ruby
sudo apt-get -y -q install gawk libreadline6-dev zlib1g-dev libssl-dev libyaml-dev libsqlite3-dev sqlite3 autoconf libgdbm-dev libncurses5-dev automake libtool bison pkg-config libffi-dev libxml2-dev libxslt-dev libxml2


# Install Postgresql
sudo apt-get -y -q install postgresql libpq-dev postgresql-contrib

# Set Password to test for user postgres
sudo -u postgres psql -c "ALTER USER postgres WITH PASSWORD 'test';"

The setup.sh script install different dependencies like ruby or redis to set up the virtual machine exactly how you need it:

#!/bin/bash

set -e

echo "Instaling for rof"

# Installing vagrant keys
mkdir ~/.ssh
chmod 700 ~/.ssh
cd ~/.ssh
wget --no-check-certificate 'https://raw.github.com/mitchellh/vagrant/master/keys/vagrant.pub' -O authorized_keys
chmod 600 ~/.ssh/authorized_keys
chown -R vagrant ~/.ssh

# Node.js Setup
wget --retry-connrefused -q -O - https://raw.github.com/creationix/nvm/master/install.sh | sh
source ~/.nvm/nvm.sh

nvm install 0.10.18
nvm alias default 0.10.18

echo "source ~/.nvm/nvm.sh" >> ~/.bash_profile

# RVM Install
wget --retry-connrefused -q -O - https://get.rvm.io | bash -s stable
source /home/vagrant/.rvm/scripts/rvm

rvm autolibs read-fail

rvm install 2.0.0-p195

gem install bundler zeus

You don’t have any limits what you can run in your virtual machine through these scripts.

Building the Machine

We’ve added a create_box.sh script that makes it easy for you to get started

#!/bin/bash

set -e

#export PACKER_LOG=1
rm packer_virtualbox_virtualbox.box || true
packer build -only=virtualbox packer.json
vagrant box remove vagrant_machine || true
vagrant box add vagrant_machine packer/packer_virtualbox_virtualbox.box

You will then see Virtualbox start up and build the machine

Run the script and it will create the packer machine and import it into vagrant. Then all you have to do is run

vagrant destroy
vagrant up

And you have your development environment set up.

You can now get into the machine with vagrant ssh and start coding.

Conclusions

Vagrant is an incredibly powerful tool and together with Packer it is easy to build development environments for your whole team.

But this is only the beginning. Packer can go much further than just providing your development environment. We are currently implementing Packer as the tool to build all of our test infrastructure servers. This new set of tools is great for Immutable Infrastructure and Continuous Deployment so you can build more stable, secure and easy to change infrastructure than ever before.

Let us know in the comments how you use Packer and Vagrant. We are excited to hear your thoughts!

Additional Links

• Packer Documentation
• Vagrant Documentation
• Our blog post about Immutable Infrastructure

• Building Vagrant Machines with Packer