ruby - 如何正确实现 Net::SSH 端口转发

Question

我一直在尝试让端口转发与 Net::SSH 一起正常工作。据我了解，如果我希望能够从同一个 Ruby 程序中使用它，我需要 fork 出 Net::SSH session ，以便事件处理循环实际上可以处理通过连接发送的数据包。但是，这会导致您在以下内容中看到的丑陋之处:

#!/usr/bin/env ruby -w
require 'net/ssh'
require 'httparty'
require 'socket'
include Process

log = Logger.new(STDOUT)
log.level = Logger::DEBUG

local_port = 2006
child_socket, parent_socket = Socket.pair(:UNIX, :DGRAM, 0)
maxlen = 1000
hostname = "www.example.com"

pid = fork do
  parent_socket.close
  Net::SSH.start("hostname", "username") do |session|
    session.logger = log
    session.logger.sev_threshold=Logger::Severity::DEBUG
    session.forward.local(local_port, hostname, 80)
    child_socket.send("ready", 0)
    pidi = fork do
      msg = child_socket.recv(maxlen)
      puts "Message from parent was: #{msg}"
      exit
    end
    session.loop do
      status = waitpid(pidi, Process::WNOHANG)
      puts "Status: #{status.inspect}"
      status.nil?
    end
  end
end

child_socket.close

puts "Message from child: #{parent_socket.recv(maxlen)}"
resp = HTTParty.post("http://localhost:#{local_port}/", :headers => { "Host" => hostname } )
# the write cannot be the last statement, otherwise the child pid could end up
# not receiving it
parent_socket.write("done")
puts resp.inspect

谁能告诉我一个更优雅/更好的工作解决方案？

Answer 1

我花了很多时间试图弄清楚如何正确地实现端口转发，然后我从 net/ssh/gateway 库中获得灵感。我需要一个强大的解决方案，可以在各种可能的连接错误后运行。这是我现在正在使用的，希望对您有所帮助:

require 'net/ssh'

ssh_options = ['host', 'login', :password => 'password']
tunnel_port = 2222
begin
  run_tunnel_thread = true
  tunnel_mutex = Mutex.new
  ssh = Net::SSH.start *ssh_options
  tunnel_thread = Thread.new do
    begin
      while run_tunnel_thread do
        tunnel_mutex.synchronize { ssh.process 0.01 }
        Thread.pass
      end
    rescue => exc
      puts "tunnel thread error: #{exc.message}"
    end
  end
  tunnel_mutex.synchronize do
    ssh.forward.local tunnel_port, 'tunnel_host', 22
  end

  begin
    ssh_tunnel = Net::SSH.start 'localhost', 'tunnel_login', :password => 'tunnel_password', :port => tunnel_port
    puts ssh_tunnel.exec! 'date'
  rescue => exc
    puts "tunnel connection error: #{exc.message}"
  ensure
    ssh_tunnel.close if ssh_tunnel
  end

  tunnel_mutex.synchronize do
    ssh.forward.cancel_local tunnel_port
  end
rescue => exc
  puts "tunnel error: #{exc.message}"
ensure
  run_tunnel_thread = false
  tunnel_thread.join if tunnel_thread
  ssh.close if ssh
end