It Works On My Machine

Virtualizing Development

by Eli Golding / eligolding@gmail.com / @eli_golding

Why Virtualize?

Traditional setup

Individual local development machines

new dev joins the team they must...

install web server (apache/nginx)...

install PHP...

install MySQL...

install Redis, Memcache, NPM, RVM...

If the dev is not a sysadmin, he might need a ton of help doing this.

we're not done...

configure all the things...

get the code...

attempt to serve the application...

configure some more things to get it to work...

Dev #1

Apache 2.2.15
PHP 5.5.4
MySQL 5.4.5

Dev #2

Apache 2.2.3
PHP 5.5.1
MySQL 5.4.3

Dev #3

Apache 2.2.24
PHP 5.4.3
MySQL 5.2.5

Dev #4

Apache 2.1.8
PHP 5.3.24
MySQL 5.1.6

lets not forget about staging and production and when they finally get a chance to code, the first push to prod results in...

IT Automation Tools

explain what a provisioner is!

Problems with using just a provisioner

Still bound to hardware

Can only have one setup

Inflexible infrastructure

Potential to cause problems with main OS

Port conflicts

Different type of machine than production

explain what a provisioner is!

Virtualization

“Virtualization, in computing, refers to the act of creating a virtual (rather than actual) version of something, including but not limited to a virtual computer hardware platform, operating system (OS), storage device, or computer network resources.” A virtual machine is a software implementation of a computer, running a complete operating system stack on a virtualizer. It is a full implementation of a computer with a virtual disk, memory and CPU. The machine running the virtualizer is the Host system. The virtual machine running on the virtualizer is the Guest system. As far as the Guest operating system is concerned, it is running on real hardware. From the perspective of the Host, all of the Guest's resources are used by the virtualizer program. A Box, or base image, is the prepackaged virtual machine that Vagrant will manage.

Virtualization Providers

Virtualization the good parts

Multiple VMs on one machine
Flexibility
Doesn't mess up your host machine
Dev == Production

Virtualization the not so good parts

Setup is very time consuming
Must distribute it
Maintain and Update
Redistribute

Vagrant is a command line tool that fully controls the creation and provisioning of virtual machines.

Everything is configured in a single file (VagrantFile) that part of the project.

Can be viewed as a wrapper around the VM provider and the provisioner.

The VagrantFile is checked into version control, allowing for great portability.

So now we have

Easy to share
Same exact version across all systems
Fast ramp up
"WORKS ON OUR MACHINE"

VagrantFile

  Vagrant.configure(2) do |config|

	config.vm.box = "ubuntu/trusty64"

	config.vm.network "forwarded_port", guest: 80, host: 8080

	config.vm.network "private_network", ip: "192.168.33.10"

	config.vm.synced_folder ".", "/var/www"

	config.vm.provision "shell", inline: <<-SHELL
	  sudo apt-get install -y apache2
	SHELL

  end

Box

  config.vm.box = "ubuntu/trusty64"

Configures the base box of the machine. Value should be the name of an installed box or a shorthand name of a box in HashiCorp's Atlas.

box_url

Network

  config.vm.network "forwarded_port", guest: 80, host: 8080

  config.vm.network "private_network", ip: "192.168.33.10"

Configures networks on the machine.

Synced Folder

  config.vm.synced_folder ".", "/var/www"

Synced folders enable Vagrant to sync a folder on the host machine to the guest machine, allowing you to continue working on your project's files on your host machine.

Provision

  config.vm.provision "shell", inline: <<-SHELL
    sudo apt-get install -y apache2
  SHELL

Set the Provisioners that will automatically install software, alter configurations, and more on the machine as part of the vagrant up process.

Vagrant Commands

vagrant up: start a new instance of the VM
vagrant suspend: save state of the running VM
vagrant resume: restart suspended VM
vagrant halt: powers off VM
vagrant reload: reboot VM
vagrant destroy: Completely deletes the machine

Infrastructure as Code

Resource

Represents a piece of your infrastructure and it's desired state.

Common Resources

Running a Command

  execute "composer-install" do
    cwd '/var/www/app'
    command "composer install"
  end

Changing directory permissions

  directory "/vagrant/app/cache" do
    owner "vagrant"
    group "vagrant"
    mode 0777
    action :create
  end

Creating a symlink

  link "/etc/nginx/sites-enabled/my-cool-site" do
    to "/etc/nginx/sites-available/my-cool-site"
  end

Running apt-get update

  execute "apt-get update" do
    command "apt-get update"
  end

Installing a package

  apt_package "curl" do
    action :install
  end

Installing multiple packages

  php_packages = ['php5-cli','php5-curl','php5-mysql']

  php_packages.each do |p|
    apt_package p do
      action :install
    end
  end

Applying a template

  template "/etc/nginx/sites-available/my-awesome-site" do
    source "vhost.erb"
    variables({
      :doc_root    => '/var/www',
      :server_name => 'vagrant.rox'
    })
    action :create
    notifies :restart, resources(:service => "nginx")
  end

  server {
      listen   80;

      root <%= @doc_root %>;
      index index.html index.php;

      server_name <%= @server_name %>;

      location / {
          try_files $uri $uri/ /index.php;
      }

      error_page 404 /404.html;

      error_page 500 502 503 504 /50x.html;
      location = /50x.html {
          root /usr/share/nginx/www;
      }

      location ~ \.php$ {
          fastcgi_split_path_info ^(.+\.php)(/.+)$;
          fastcgi_pass unix:/var/run/php5-fpm.sock;
          fastcgi_index index.php;
          fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
          include fastcgi_params;
      }
  }

Recipe

Configuration file that describes resources and their desired state.

Cookbook

Recipes are stored in cookbooks.

Cookbook contain recipes, template, files, custom resources, etc.

"If you want to increase innovation, you have to lower the cost of failure."

Joi Ito
Director, MIT Media Lab

Questions?

It Works On My Machine Virtualizing Development by Eli Golding / eligolding@gmail.com / @eli_golding

It Works On My Machine – Virtualizing Development – Traditional setup

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