Check Vagrant version

Vagrantfile

MIN_REQUIRED_VAGRANT_VERSION = '1.2.1'

if Vagrant::VERSION < MIN_REQUIRED_VAGRANT_VERSION
  $stderr.puts "ERROR: We require Vagrant version >=#{min_required_vagrant_version}. Please upgrade. http://downloads.vagrantup.com/\n"
  exit 1
end

Vagrant.configure("2") do |config|
  config.vm.box = "precise64"
  config.vm.hostname = 'foo'
  config.vm.box_url = "http://files.vagrantup.com/precise64.box"
end

Although this is probably years old at this point, it should be noted that this version check appears to do lexicographical comparison. For example, this results in 2.2.10 being handled as if it were an earlier version than 2.2.6 (for example).

I don't know when this was added (or if it was always there), but Vagrant now has their own function for checking the version:

if Vagrant.version?("< 1.2.1")
    ...
end

Yeah, this is pretty old at this point (2013?), I think this pre-dates the Vagrant.version? method:

I later found that version comparisons in Ruby are fairly simple to do with the Gem library as well:

Gem::Version.new(Vagrant::VERSION) < Gem::Version.new(MIN_REQUIRED_VAGRANT_VERSION)