Vagrant & Chef

         ... for Drupal developers

Alex Dergachev | Co-founder of Evolving Web

@dergachev on github | @dergachev on twitter

Vagrant is...

A wrapper on VBoxManage,
A workflow,
A way of life.

Installing Vagrant

Run these GUI installers:

Both are simple, reliable, and work on Windows/Mac/Linux

Vagrant Docs

Base boxes

Just a VM image with:

"vagrant" user & ssh keys
virtualbox guest additions
installed ruby, chef, puppet

Where to find base boxes

Community boxes from http://www.vagrantbox.es/
official builds have URLs like files.vagrantup.com/*.box

Base box docs

vagrantup.com doc on base boxes
Tutorial on manually building a base box
Vewee automates box creation.
- veewee tutorial

Vagrant workflow

vagrant box add precise64
  http://files.vagrantup.com/precise64.box
vagrant init
vagrant up # --no provision
vagrant reload
vagrant provision
vagrant destroy --force && vagrant up
vagrant ssh  # -p -- -l alex
ls /vagrant # inside the VM
vagrant package # outputs ./package.box
vagrant snap take # requires vagrant-snap plugin

Vagrantfile config

config.vm.forward_port 80, 4567
config.vm.box = "precise64"
config.vm.share_folder "foo", "/guest/path", 
  "/host/path", :nfs => true
config.vm.network :hostonly, "10.11.12.13"
 # config.vm.network :bridged
config.vm.customize 
  ["modifyvm", :id, "--memory", 1024]
config.vm.provision :shell, 
  :inline => "echo foo > /vagrant/test"
 # support for multiple VMs

Provisioning

Installing software on the VM

Supported provisioners

shell
chef-solo
chef
Puppet

Shell provisioner

config.vm.provision :shell, 
  :inline => "apt-get -y update"

config.vm.provision :shell, 
  :inline => "sudo apt-get -y vim git"

Chef-solo provisioner

config.vm.provision :chef_solo do |chef|
  chef.cookbooks_path = 
    ["cookbooks", "~/company/cookbooks"]
  chef.add_recipe("apache")
  chef.add_recipe("php")
  chef.json = {
    :load_limit => 42,
    :chunky_bacon => true
  }
end

See Vagrant chef_solo docs and iterative chef tutorial.

Ruby for Chef

Just enough not to freak out

Methods

def double(num)
  num * 2
end

double 33 # => 66

Ruby Strings

:bob == 'bob'.to_sym

%w{git vim mysql} == ['git', 'vim', 'mysql']

"head #{var} tail" == "head "+var+" tail"

Ruby dictionaries

options = {
  :deploy_drupal => { 
    :apache_group => 'vagrant', 
    :sql_load_file => '/vagrant/db/fga.sql.gz',
    :source =>  "/vagrant/public/fga/www",
  },
  :mysql => {
    :server_root_password => "root",
  },
}

DSL... wtf?

template "/etc/mysql/grants.sql" do
  source "grants.sql.erb"
  owner "root"
  group "root"
end

template("/etc/mysql/grants.sql", function() {  
  this.source("grants.sql.erb");
  this.owner("root");
  this.group("root");
});

Writing a cookbook

Cookbooks and recipes

A cookbooks contains recipes, which are very simple ruby scripts that install software or otherwise configure the VM.

Recipes read data from attributes, and call built-in or custom resources, which are helper methods that do all the work.

Cookbook structure

Example Cookbook

Adapted from @opscode/getting-started:

recipes/
- default.rb
- other_recipe.rb
attributes/
- default.rb
templates/
- httpd.conf.erb
metadata.rb
README.md

Resources

Recipes are ruby scripts, but with minimal code.
Recipes specify which system configuration Resources chef should execute
Resource implementations (called Providers) actually do the work.
Simplifying, recipes contain "API calls" to resources, with optional arguments.

Install a template

template '/var/www/sites/default/settings.php' do
  # action :create
  # action :create_if_missing
  source "settings.php.erb"
  variables ( {
    :user => 'root',
    :pass => node[:mysql]['root_password'],
    :name => 'drupalsite_v1',
  })
end

Install packages

package "tar" do
  action :install
end

package %w{vim git}

php_pear "uploadprogress"

gem_package "syntax"

Execute bash

execute "download drupal" do
  cwd '/var/www'
  command "drush dl drupal-7.20"
  creates '/var/www/drupal-7.20/index.php'
end

creates tells chef not to re-execute the resource if index.php is already in place.

Deploy from git

deploy "/var/www" do 
  repo "git@github.com/mycompany/project"
  user "www-data"
  group "www-data"
  revision "master"
  action :sync # default value, also :checkout
end

Controlling services

 # runs /etc/init.d/apache2 start|stop|...
service "apache2" do
  supports :status => true, 
    :restart => true, :reload => true
  action [ :enable, :start ]
end

Install a user

user "sam" do
     home "/home/sam"
     shell "/bin/zsh"
     comment "Sam loves DevOps"
     action :create
     password :$1$pfFfDG3M$22vsMsPnn93ZnuodI86Ec0
end

Add a vhost config

web_app 'drupalcampottawa' do
  template "web_app.conf.erb"
  port 80
  server_name 'drupalcampottawa.com'
  docroot '/var/www/dcampottawa'
  notifies :restart, 
    resources("service[apache2]"), 
    :delayed
end

web_app is custom resource defined in the apache2 cookbook