Issue 4234 - Migrate Discourse to a Docker-based setup

Vagrantfile

 require 'yaml'
 
 VAGRANTFILE_API_VERSION = "2"
 REPOSITORY_DIR = File.dirname(__FILE__)
 DEPENDENCY_SCRIPT = File.join(REPOSITORY_DIR, "ensure_dependencies.py")
 
 if !system("python", DEPENDENCY_SCRIPT)
   error = Vagrant::Errors::VagrantError
   error.error_message("Failed to ensure dependencies being up-to-date!")
   raise error
 end
 
 def define_standard_vm(config, host_name, ip, role=nil)
   config.vm.define host_name do |config|
-    config.vm.box = 'precise64'
-    config.vm.box_url = 'http://cloud-images.ubuntu.com/vagrant/precise/current/precise-server-cloudimg-amd64-vagrant-disk1.box'
+    if host_name == 'server10'

[mathias, 2016/07/13 17:48:03]

(That is not beautiful but fine for now due to our intention to improve on node
classification and provide a more general Docker integration in the very near
future.)

+      config.vm.box = 'precise64_docker'
+      config.vm.box_url = 'http://nitron-vagrant.s3-website-us-east-1.amazonaws.com/vagrant_ubuntu_12.04.3_amd64_virtualbox.box'
+    else
+      config.vm.box = 'precise64'
+      config.vm.box_url = 'http://cloud-images.ubuntu.com/vagrant/precise/current/precise-server-cloudimg-amd64-vagrant-disk1.box'
+    end
     config.vm.host_name = "#{host_name}.adblockplus.org"
     config.vm.network :private_network, ip: ip
     config.vm.provider :virtualbox do |vb|
       vb.customize ["modifyvm", :id, "--cpus", 1]
 
       # Work around https://www.virtualbox.org/ticket/11649
       vb.customize ['modifyvm', :id, '--natdnshostresolver1', 'on']
 
       setup_path = File.join(REPOSITORY_DIR, "hiera", "roles", "#{role}.yaml")
       setup = YAML.load_file(setup_path) rescue {}
@@ skipping 32 matching lines @@
 Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
   config_path = File.join(REPOSITORY_DIR, "modules/private/hiera/hosts.yaml")
   config_data = YAML.load_file(config_path)
   servers = config_data["servers"]
   servers.each do |server, items|
     ip = items["ip"][0]
     role = items.fetch("role", "default")
     define_standard_vm(config, server, ip, role)
   end
 end