A crude way of getting all of the host-only IP addresses I've used for vagrant vms

list_hostonly_addresses.rb

#!/usr/bin/env ruby

require 'find'

def process_vagrantfile(vagrantfile)
    box = nil

    f = File.open(vagrantfile).each do |line|
        if match = /^\s*config\.vm\.box = "([^"]+)"/.match(line) then
            box = match[1]
        end

        if match = /^\s*config\.vm\.network :hostonly, "([^"]+)"/.match(line) then
            puts "#{match[1]} #{box}"
        end
    end
end

Find.find(ENV["PWD"]) do |path|
    if path.end_with? "Vagrantfile" then
        process_vagrantfile path
    end
end