Class: LitmusPaper::AgentCheckServer

Inherits:
Object
  • Object
show all
Defined in:
lib/litmus_paper/agent_check_server.rb

Constant Summary collapse

CRLF = 
"\r\n"

Instance Method Summary collapse

Constructor Details

#initialize(litmus_paper_config, services, workers, pid_file, daemonize) ⇒ AgentCheckServer

Returns a new instance of AgentCheckServer.



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# File 'lib/litmus_paper/agent_check_server.rb', line 11

def initialize(litmus_paper_config, services, workers, pid_file, daemonize)
  LitmusPaper.configure(litmus_paper_config)
  @services = services
  @workers = workers
  @pid_file = pid_file
  @daemonize = daemonize
  @control_sockets = @services.keys.map do |port|
    TCPServer.new(port)
  end
  trap(:INT) { exit }
  trap(:TERM) { exit }
end

Instance Method Details

#accept_loop(sockets) ⇒ Object

Stolen pattern from ruby Socket, modified to return the service based on the accepting port



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# File 'lib/litmus_paper/agent_check_server.rb', line 26

def accept_loop(sockets)
  if sockets.empty?
    raise ArgumentError, "no sockets"
  end
  loop {
    readable, _, _ = IO.select(sockets)
    readable.each { |r|
      begin
        sock, addr = r.accept_nonblock
        _, remote_port, _, remote_ip = sock.peeraddr
        LitmusPaper.logger.debug "Received request from #{remote_ip}:#{remote_port}"
        service = @services[r.local_address.ip_port]
      rescue IO::WaitReadable
        next
      end
      yield sock, service
    }
  }
end

#respond(sock, message) ⇒ Object 



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# File 'lib/litmus_paper/agent_check_server.rb', line 46

def respond(sock, message)
  sock.write(message)
  sock.write(CRLF)
end

#run ⇒ Object 



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# File 'lib/litmus_paper/agent_check_server.rb', line 57

def run
  if @daemonize
    Process.daemon
  end
  write_pid(@pid_file)
  child_pids = []

  @workers.times do
    child_pids << spawn_child
  end

  kill_children = Proc.new { |signo|
    child_pids.each do |cpid|
      begin
        Process.kill(:INT, cpid)
      rescue Errno::ESRCH
      end
    end
    File.delete(@pid_file) if File.exists?(@pid_file)
    exit
  }

  trap(:INT, &kill_children)
  trap(:TERM, &kill_children)

  loop do
    pid = Process.wait
    LitmusPaper.logger.error("Process #{pid} quit unexpectedly")
    child_pids.delete(pid)
    child_pids << spawn_child
  end
end

#spawn_child ⇒ Object 



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# File 'lib/litmus_paper/agent_check_server.rb', line 90

def spawn_child
  fork do
    accept_loop(@control_sockets) do |sock, service|
      respond(sock, AgentCheckHandler.handle(service))
      sock.close
    end
  end
end

#write_pid(pid_file) ⇒ Object 



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# File 'lib/litmus_paper/agent_check_server.rb', line 51

def write_pid(pid_file)
  File.open(pid_file, 'w') do |f|
    f.write(Process.pid)
  end
end