module Dockerb

# File lib/dockerb.rb, line 9
def compile(docker_file="Dockerfile", &block)
  return (yield if block) unless File.exist?("#{docker_file}.erb")
  ensure_not_older_than_last(docker_file)
  compile_dockerfile(docker_file, &block)
end

# File lib/dockerb.rb, line 24
def compile_dockerfile(docker_file, &block)
  File.write(docker_file, Context.compile(File.read("#{docker_file}.erb")))
  yield if block
ensure
  File.unlink(docker_file) if File.exist?(docker_file) && block
end

# File lib/dockerb.rb, line 17
def ensure_not_older_than_last(docker_file)
  return unless File.exist?(docker_file)
  return unless old = File.read(docker_file)[SEARCH, 1]
  return unless Gem::Version.new(old) > Gem::Version.new(VERSION)
  raise "Previous file was generated by dockerb #{old}, use it or a newer version."
end