在 Ruby 中从 Unix 套接字读取/写入

Question

我正在尝试使用 Ruby 从 UNIX 套接字进行连接、读取和写入。它是 haproxy 使用的统计套接字。

我的代码如下：

require 'socket'
socket = UNIXSocket.new("/tmp/haproxy.stats.socket")

# First attempt: works

socket.puts("show stat")

while(line = socket.gets) do
  puts line
end

# Second attemp: fails

socket.puts("show stat")

while(line = socket.gets) do
  puts line
end

第一次成功，但第二次尝试失败。我不知道为什么。

# pxname,svname,qcur,qmax,scur,smax,slim,stot,bin,bout,dreq,dresp,ereq,econ,eresp,wretr,wredis,status,weight,act,bck,chkfail,chkdown,lastchg,downtime,qlimit,pid,iid,sid,throttle,lbtot,tracked,type,rate,rate_lim,rate_max,check_status,check_code,check_duration,hrsp_1xx,hrsp_2xx,hrsp_3xx,hrsp_4xx,hrsp_5xx,hrsp_other,hanafail,req_rate,req_rate_max,req_tot,cli_abrt,srv_abrt,
stats,FRONTEND,,,0,0,2000,0,0,0,0,0,0,,,,,OPEN,,,,,,,,,1,1,0,,,,0,0,0,0,,,,0,0,0,0,0,0,,0,0,0,,,
stats,BACKEND,0,0,0,0,2000,0,0,0,0,0,,0,0,0,0,UP,0,0,0,,0,22,0,,1,1,0,,0,,1,0,,0,,,,0,0,0,0,0,0,,,,,0,0,
legacy_socket,FRONTEND,,,0,0,1000,0,0,0,0,0,0,,,,,OPEN,,,,,,,,,1,2,0,,,,0,0,0,0,,,,0,0,0,0,0,0,,0,0,0,,,
all,FRONTEND,,,0,0,10000,0,0,0,0,0,0,,,,,OPEN,,,,,,,,,1,3,0,,,,0,0,0,0,,,,0,0,0,0,0,0,,0,0,0,,,
socket_backend,socket,0,0,0,0,200,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,22,22,,1,4,1,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
socket_backend,socket,0,0,0,0,200,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,22,22,,1,4,2,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
socket_backend,socket,0,0,0,0,200,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,22,22,,1,4,3,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
socket_backend,socket,0,0,0,0,200,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,22,22,,1,4,4,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
socket_backend,socket,0,0,0,0,200,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,22,22,,1,4,5,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
socket_backend,socket,0,0,0,0,200,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,22,22,,1,4,6,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
socket_backend,socket,0,0,0,0,200,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,22,22,,1,4,7,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
socket_backend,socket,0,0,0,0,200,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,21,21,,1,4,8,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
socket_backend,socket,0,0,0,0,200,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,21,21,,1,4,9,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
socket_backend,socket,0,0,0,0,200,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,21,21,,1,4,10,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
socket_backend,BACKEND,0,0,0,0,0,0,0,0,0,0,,0,0,0,0,DOWN,0,0,0,,1,21,21,,1,4,0,,0,,1,0,,0,,,,0,0,0,0,0,0,,,,,0,0,
api_backend,api,0,0,0,0,200,0,0,0,,0,,0,0,0,0,UP,1,1,0,0,0,22,0,,1,5,1,,0,,2,0,,0,L4OK,,0,0,0,0,0,0,0,0,,,,0,0,
api_backend,api,0,0,0,0,1,0,0,0,,0,,0,0,0,0,UP,1,1,0,0,0,22,0,,1,5,2,,0,,2,0,,0,L4OK,,0,0,0,0,0,0,0,0,,,,0,0,
api_backend,api,0,0,0,0,1,0,0,0,,0,,0,0,0,0,DOWN,1,1,0,0,1,21,21,,1,5,3,,0,,2,0,,0,L4CON,,0,0,0,0,0,0,0,0,,,,0,0,
api_backend,BACKEND,0,0,0,0,0,0,0,0,0,0,,0,0,0,0,UP,2,2,0,,0,22,0,,1,5,0,,0,,1,0,,0,,,,0,0,0,0,0,0,,,,,0,0,
www_backend,ruby-www,0,0,0,0,10000,0,0,0,,0,,0,0,0,0,UP,1,1,0,0,0,22,0,,1,6,1,,0,,2,0,,0,L4OK,,0,0,0,0,0,0,0,0,,,,0,0,
www_backend,BACKEND,0,0,0,0,0,0,0,0,0,0,,0,0,0,0,UP,1,1,0,,0,22,0,,1,6,0,,0,,1,0,,0,,,,0,0,0,0,0,0,,,,,0,0,

/Users/Olly/Desktop/haproxy_stats.rb:14:in `write': Broken pipe (Errno::EPIPE)
    from /Users/Olly/Desktop/haproxy_stats.rb:14:in `puts'
    from /Users/Olly/Desktop/haproxy_stats.rb:14

问题是什么？有关于使用 UNIX 套接字和 Ruby 的很好的参考吗？

Answer 1

Olly，

HAproxy 在第一个请求后关闭连接，除非您使用“提示”命令（请参阅 http://haproxy.1wt.eu/download/1.4/doc/configuration.txt第9.2节）：

#!/usr/bin/env ruby                                                                                                                         

require 'socket'                                                                                                                            

socket = UNIXSocket.new("/tmp/haproxy.stats.socket")                                                                                            

# Goes interactive mode
socket.puts("prompt")                                                                                                                       

# Ask statistics every second                                                                                                                             
while true                                                                                                                                  
  socket.puts("show stat")                                                                                                                  
  socket.each_char do |c|
    # We had the prompt, break out                                                                                                   
    break if c == '>'                                                                                                                       
    print c                                                                                                                                 
  end                                                                                                                                       

  sleep 1                                                                                                                                   
end            

Answer 2

看起来连接在第一个请求后已关闭。我不认为你做错了什么。 HAProxy stats 套接字可能被设计为响应单个命令，然后关闭连接。

我认为您需要为每个请求重新连接。

如果您查看这篇博文< /a> 这是关于使用 HAProxy stats 套接字与 socat 那么这是有道理的，因为你管道show stat 命令输入 socat，socat 从套接字读取数据，直到它关闭。

Answer 3

我在使用socket.puts时也遇到了同样的问题，你可以使用socket.write而不是socket.puts来修复它。

#!/usr/bin/evn ruby
# -*- coding: UTF-8 -*-

require 'rubygems'
require 'uri'
require 'socket'
require 'yaml'

SOCKET = URI.parse("/var/run/haproxy/haproxy.sock")

def get_info
  UNIXSocket.open(SOCKET.path) do |socket|
    socket.write("show info;")
    info = YAML::load socket
    #info.each {|key, value| puts "#{key} ➤ #{value}"}
  end
end

puts get_info["Uptime_sec"]

查看这个 gem 了解更多信息，源代码是 此处。

Answer 4

您可以使用人套接字。您可以使用套接字类，就像它是 C 函数一样。

我发现手册页非常有用。