hang_for_reals.rb

extra.rb

module LXC
  module Extra
    def execute(&block)
      r,w = IO.pipe
      pid = attach do
        ENV.clear
        ENV['PATH'] = '/usr/bin:/bin:/usr/sbin:/sbin'
        ENV['TERM'] = 'xterm-256color'
        ENV['SHELL'] = '/bin/bash'
        r.close
        begin
          out = block.call
          w.write(Marshal.dump(out))
        rescue Exception => e
          w.write(Marshal.dump(e))
        end
      end

      Process.wait(pid)

      w.close
      o = nil
      if r.ready?
        o = Marshal.load(r.read)
      end
      r.close
      raise o if o.is_a?(Exception)
      o
    end

gistfile1.rb

require 'lxc'
require 'lxc/extra'

container = LXC::Container.new('simple')
Thread.new do
  puts "A"
  container.execute do
    puts "B"
    sleep 2
    puts "C"
  end
  puts "D"
end

puts "1"
container.execute do
  puts "2"
  sleep 2
  puts "3"
end
puts "4"
sleep 5

output

1
2
3
4
A
B
C
D