#!/usr/bin/env ruby
# encoding: utf-8
#
# Vagrantfile to bring up one or more VM for testing purposes.
#
# Environment Variables:
#
#   LAB_MACHINES:   Number of machines, ignored if `machines.yml` exits
#   LAB_MEMORY:     Memory in GB each machine, default: 1, ignored if `machines.yml` exists
#   LAB_CPU:        Number of CPU each machine, default: 1, ignored if `machines.yml` exists
#   LAB_RELEASE:    Ubuntu release to be used, default: bionic
#
# NOTE: vagrant-hostmanager plugin is used for private network DNS resolution.
#
#   vagrant plugin install vagrant-hostmanager
#
# Optional: install vagrant-cachier to cache apt packages

require 'yaml'

MACHINE_FILE="machines.yml"
CPU      = ENV['LAB_CPU'].to_i      == 0 ? 1 : ENV['LAB_CPU'].to_i
MEMORY   = ENV['LAB_MEMORY'].to_i   == 0 ? 1 : ENV['LAB_MEMORY'].to_i
RELEASE  = %w(bionic xenial trusty).include?( ENV['LAB_RELEASE'] ) ? ENV['LAB_RELEASE'] : 'bionic'
RELEASE_VERSIONS = { 'bionic' => '18.04', 'xenial' => '16.04', 'trusty' => '14.04' }

def complete_machine_with_env(machine)
  %i( cpu memory release ).each { |k| machine[k] ||= Object.const_get( k.to_s.upcase ) }
  machine
end

def machines_from_file
  return nil unless File.file?(MACHINE_FILE)
  machines = YAML.load(open(MACHINE_FILE).read, symbolize_names: true)
  machines.is_a?(Array) ? machines.map{ |m| complete_machine_with_env(m) } : nil
end

def machines_from_env
  unless ENV['LAB_MACHINES']
    abort "Error: environment variable LAB_MACHINES not defined! Define this variable or use a machine.yml."
  end

  number = ENV['LAB_MACHINES'].to_i == 0 ? 1 : ENV['LAB_MACHINES'].to_i
  machines = []
  number.times { |i| machines.append( complete_machine_with_env({}) ) }
  machines
end

Vagrant.configure("2") do |config|
  machines = machines_from_file || machines_from_env

  config.vm.box_check_update = false
  config.vm.synced_folder "shared/", "/home/vagrant/shared", create: true, type: "rsync"

  # vagrant-hostmanager configs
  config.hostmanager.enabled           = true
  config.hostmanager.manage_host       = false
  config.hostmanager.manage_guest      = true
  config.hostmanager.ignore_private_ip = false
  config.hostmanager.include_offline   = true

  # vagrant-cachier config
  config.cache.scope = :machine if Vagrant.has_plugin? "vagrant-cachier"

  machines.each_with_index do |m, i|
    index = i + 1
    name = m[:hostname] || "box#{index}"
    config.vm.define( name ) do |config|
      config.vm.hostname = name
      config.vm.network :private_network, ip:  "10.10.100.#{100+index}"
      config.hostmanager.aliases = %W( #{name}.lab )

      config.vm.provider "virtualbox" do |v, override|
        override.vm.box = "ubuntu/#{m[:release]}64"
        v.cpus   = m[:cpu]
        v.memory = m[:memory]*1024
      end

      config.vm.provider "libvirt" do |v, override|
        override.vm.box = "generic/ubuntu#{RELEASE_VERSIONS[m[:release]].sub('.','')}"
        v.cpus   = m[:cpu]
        v.memory = m[:memory]*1024
        v.nested = true
      end
    end
  end

end