Class: Expedite::Server::Controller

Inherits:
Object
  • Object
show all
Includes:
Expedite::Signals
Defined in:
lib/expedite/server/controller.rb

Overview

Controls the ‘expedite server`.

Constant Summary

Constants included from Expedite::Signals

Expedite::Signals::IGNORE_SIGNALS

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(foreground: true, env: nil) ⇒ Controller

Returns a new instance of Controller.



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# File 'lib/expedite/server/controller.rb', line 22

def initialize(foreground: true, env: nil)
  @foreground   = foreground
  @env          = env || default_env
  @pidfile      = @env.pidfile_path.open('a')
  @mutex        = Mutex.new
end

Instance Attribute Details

#env ⇒ Object (readonly)

Returns the value of attribute env.



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# File 'lib/expedite/server/controller.rb', line 20

def env
  @env
end

Class Method Details

.boot(options = {}) ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 16

def self.boot(options = {})
  new(options).boot
end

Instance Method Details

#boot ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 37

def boot
  env.load_helper

  write_pidfile
  set_pgid unless foreground?
  ignore_signals unless foreground?
  set_exit_hook
  set_process_title
  start_server
  exit 0
end

#foreground? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/expedite/server/controller.rb', line 29

def foreground?
  @foreground
end

#ignore_signals ⇒ Object

Ignore SIGINT and SIGQUIT otherwise the user typing ^C or ^\ on the command line will kill the server/application.



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# File 'lib/expedite/server/controller.rb', line 177

def ignore_signals
  IGNORE_SIGNALS.each { |sig| trap(sig, "IGNORE") }
end

#kill(sig) ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 85

def kill(sig)
  pid = self.pid
  Process.kill(sig, pid) if pid
rescue Errno::ESRCH
  # already dead
end

#log(message) ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 33

def log(message)
  env.log "[server] #{message}"
end

#pid ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 49

def pid
  @env.pidfile_path.read.to_i
rescue Errno::ENOENT
  nil
end

#redirect_output ⇒ Object

We need to redirect STDOUT and STDERR, otherwise the server will keep the original FDs open which would break piping. (e.g. ‘spring rake -T | grep db` would hang forever because the server would keep the stdout FD open.)



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# File 'lib/expedite/server/controller.rb', line 220

def redirect_output
  [STDOUT, STDERR].each { |stream| stream.reopen(env.log_file) }
end

#running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/expedite/server/controller.rb', line 55

def running?
  pidfile = @env.pidfile_path.open('r+')
  !pidfile.flock(File::LOCK_EX | File::LOCK_NB)
rescue Errno::ENOENT
  false
ensure
  if pidfile
    pidfile.flock(File::LOCK_UN)
    pidfile.close
  end
end

#serve(client) ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 99

def serve(client)
  log "accepted client"
  client.puts env.version

  # Corresponds to Client::Invoke#connect_to_agent
  app_client = client.recv_io
  command    = client.recv_object(env)

  args, agent = command.values_at("args", "agent")
  cmd = args.first

  if agent == "__server__"
    case cmd
    when "application_pids"
      # Corresponds to Client::Invoke#run_command
      client.puts

      unix_socket = UNIXSocket.for_fd(app_client.fileno)
      _ = unix_socket.recv_setup(env)

      client.puts Process.pid

      application_pids = []
      env.applications.pools.each do |k, pool|
        application_pids.concat(pool.all.map(&:pid))
      end
      unix_socket.send_return(application_pids, env)

      unix_socket.close
      client.close
    else
    end
  elsif Expedite::Actions.lookup(cmd)
    # Corresponds to Client::Invoke#run_command
    log "running command #{cmd}: #{args}"

    client.puts

    begin
      env.applications.with(agent) do |target|
        client.puts target.run(app_client)
      end
    rescue AgentNotFoundError => e
      unix_socket = UNIXSocket.for_fd(app_client.fileno)
      _ = unix_socket.recv_setup(env)

      args, env = unix_socket.recv_object(env).values_at("args", "env")

      client.puts Process.pid

      # boot only
      #@child_socket = client.recv_io
      #@log_file = client.recv_io
      unix_socket.send_exception(e, env)

      unix_socket.close
      client.close
    end
  else
    log "command not found #{cmd}"
    client.close
  end
rescue AgentNotFoundError => e
rescue SocketError => e
  raise e unless client.eof?
ensure
  redirect_output
end

#set_exit_hook ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 181

def set_exit_hook
  server_pid = Process.pid

  # We don't want this hook to run in any forks of the current process
  at_exit { shutdown if Process.pid == server_pid }
end

#set_pgid ⇒ Object

Boot the server into the process group of the current session. This will cause it to be automatically killed once the session ends (i.e. when the user closes their terminal).



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# File 'lib/expedite/server/controller.rb', line 171

def set_pgid
  # Process.setpgid(0, SID.pgid)
end

#set_process_title ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 224

def set_process_title
  $0 = "expedite server | #{env.app_name}"
end

#shutdown ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 188

def shutdown
  log "shutting down"

  [env.socket_path, env.pidfile_path].each do |path|
    if path.exist?
      path.unlink rescue nil
    end
  end

  thrs = []
  env.applications.pools.each do |k, pool|
    pool.all.each do |a|
      thrs << Expedite.failsafe_thread { a.stop }
    end
  end
  thrs.map(&:join)
end

#start_server ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 92

def start_server
  server = UNIXServer.open(env.socket_path)
  log "started on #{env.socket_path}"
  loop { serve server.accept }
rescue Interrupt
end

#stop ⇒ Object

timeout: Defaults to 2 seconds



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# File 'lib/expedite/server/controller.rb', line 68

def stop
  if running?
    timeout = Time.now + @env.graceful_termination_timeout
    kill 'TERM'
    sleep 0.1 until !running? || Time.now >= timeout

    if running?
      kill 'KILL'
      :killed
    else
      :stopped
    end
  else
    :not_running
  end
end

#write_pidfile ⇒ Object 



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# File 'lib/expedite/server/controller.rb', line 206

def write_pidfile
  if @pidfile.flock(File::LOCK_EX | File::LOCK_NB)
    @pidfile.truncate(0)
    @pidfile.write("#{Process.pid}\n")
    @pidfile.fsync
  else
    raise "Failed to lock #{@env.pidfile_path}"
  end
end