should allow extend Vagrantfile with Vagrantfile-ext.rb

[hoatle]

Using vagrant_config_override.json is for normal users.

With Vagrantfile-ext.rb, we can give users power users to customize at the highest level.

This is required when vagrant_config.json is not enough to customize the VM.

Related: https://groups.google.com/forum/#!topic/vagrant-up/g68oH8-JrCE

For example, now users want to use https://github.com/devopsgroup-io/vagrant-hostmanager it's impossible with vagrant_config_override.json

Note: users are only allowed to use vagrant_config_override.json to customize the vagrant config for now.

Use Vagrantfile-ext.rb if available. Note: don't use this if you don't know what you're going to do, usually using vagrant_config_override.json is enough in most cases.

Note: allows users to choose the path and the name for Vagrantfile-override on the vagrant_config_override.json file.

The loading order:

• Vagrantfile
• vagrant_config.json
• vagrant_config_override.json (optional)
• Vagrantfile.ext.rb (optional)

And users can optionally add vagrant_config_ext.json, vagrant_config_ext_override.json if they want, however, this is rather complicated, don't do this if you don't know what you're going to do.

When this issue is resolved, users can use Vagrantfile-ext.rb.

[hoatle]

the use case is: now I want to use https://github.com/devopsgroup-io/vagrant-hostmanager but it's impossible for now (waits for #186).

Luckily, it's possible now with Vagrantfile-ext.rb

I just need to create Vagrantfile-ext.rb with the following content:

# -*- mode: ruby -*-
# vi: set ft=ruby :

# we want to resemble the code from the Vagrantfile file
# users adjust the settings here
plugins = [{
  '_id' => '0',
  'name' => 'vagrant-hostmanager',
  'config_key' => 'hostmanager',
  'required' => true,
  'enabled' => true,
  'manage_host' => true,
  'manage_guest' => true,
  'ignore_private_ip' => true
}]

# this is not supposed to be edited by users
Vagrant.configure('2') do |config|

  plugins.each do |plugin|
    plugin_name = plugin['name']
    if plugin['required'] == true
      unless Vagrant.has_plugin?(plugin_name)
        puts red("required: '$ vagrant plugin install #{plugin_name}'")
        exit!
      end
    end

    if Vagrant.has_plugin?(plugin_name) and plugin.key?('config_key')
      config_key = plugin['config_key']
      if 'hostmanager' == config_key

        unless plugin['enabled'].nil?
          config.hostmanager.enabled = plugin['enabled']
        end

        unless plugin['manage_host'].nil?
          config.hostmanager.manage_host = plugin['manage_host']
        end

        unless plugin['manage_guest'].nil?
          config.hostmanager.manage_guest = plugin['manage_guest']
        end

        unless plugin['ignore_private_ip'].nil?
          config.hostmanager.ignore_private_ip = plugin['ignore_private_ip']
        end

        unless plugin['include_offline'].nil?
          config.hostmanager.include_offline = plugin['include_offline']
        end

        unless plugin['aliases'].nil?
          config.hostmanager.aliases = plugin['aliases']
        end

        # workaround for :public_network
        config.hostmanager.ip_resolver = proc do |vm, resolving_vm|
          read_ip_address(vm)
        end
      end
    end
  end
end

# thanks to https://github.com/devopsgroup-io/vagrant-hostmanager/issues/121#issuecomment-69050265
$logger = Log4r::Logger.new('Vagrantfile-ext')

def read_ip_address(machine)
  command = "LANG=en ifconfig  | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print $1 }'"
  result  = ""

  $logger.info "Processing #{ machine.name } ... "

  begin
    # sudo is needed for ifconfig
    machine.communicate.sudo(command) do |type, data|
      result << data if type == :stdout
    end
    $logger.info "Processing #{ machine.name } ... success"
  rescue
    result = "# NOT-UP"
    $logger.info "Processing #{ machine.name } ... not running"
  end

  # the second inet is more accurate
  result.chomp.split("\n").last
end

and it should work.