1 # -*- encoding: binary -*-
2 require "unicorn/ssl_server"
4 # This is the process manager of Unicorn. This manages worker
5 # processes which in turn handle the I/O and application process.
6 # Listener sockets are started in the master process and shared with
7 # forked worker children.
9 # Users do not need to know the internals of this class, but reading the
10 # {source}[http://bogomips.org/unicorn.git/tree/lib/unicorn/http_server.rb]
11 # is education for programmers wishing to learn how \Unicorn works.
12 # See Unicorn::Configurator for information on how to configure \Unicorn.
13 class Unicorn::HttpServer
15 attr_accessor :app, :request, :timeout, :worker_processes,
16 :before_fork, :after_fork, :before_exec,
17 :listener_opts, :preload_app,
18 :reexec_pid, :orig_app, :init_listeners,
19 :master_pid, :config, :ready_pipe, :user
20 attr_reader :pid, :logger
21 include Unicorn::SocketHelper
22 include Unicorn::HttpResponse
23 include Unicorn::SSLServer
25 # backwards compatibility with 1.x
26 Worker = Unicorn::Worker
28 # all bound listener sockets
31 # listeners we have yet to bind
34 # This hash maps PIDs to Workers
37 # We use SELF_PIPE differently in the master and worker processes:
39 # * The master process never closes or reinitializes this once
40 # initialized. Signal handlers in the master process will write to
41 # it to wake up the master from IO.select in exactly the same manner
42 # djb describes in http://cr.yp.to/docs/selfpipe.html
44 # * The workers immediately close the pipe they inherit from the
45 # master and replace it with a new pipe after forking. This new
46 # pipe is also used to wakeup from IO.select from inside (worker)
47 # signal handlers. However, workers *close* the pipe descriptors in
48 # the signal handlers to raise EBADF in IO.select instead of writing
49 # like we do in the master. We cannot easily use the reader set for
50 # IO.select because LISTENERS is already that set, and it's extra
51 # work (and cycles) to distinguish the pipe FD from the reader set
52 # once IO.select returns. So we're lazy and just close the pipe when
53 # a (rare) signal arrives in the worker and reinitialize the pipe later.
56 # signal queue used for self-piping
59 # list of signals we care about and trap in master.
60 QUEUE_SIGS = [ :WINCH, :QUIT, :INT, :TERM, :USR1, :USR2, :HUP, :TTIN, :TTOU ]
63 # We populate this at startup so we can figure out how to reexecute
64 # and upgrade the currently running instance of Unicorn
65 # This Hash is considered a stable interface and changing its contents
66 # will allow you to switch between different installations of Unicorn
67 # or even different installations of the same applications without
68 # downtime. Keys of this constant Hash are described as follows:
70 # * 0 - the path to the unicorn/unicorn_rails executable
71 # * :argv - a deep copy of the ARGV array the executable originally saw
72 # * :cwd - the working directory of the application, this is where
73 # you originally started Unicorn.
75 # To change your unicorn executable to a different path without downtime,
76 # you can set the following in your Unicorn config file, HUP and then
77 # continue with the traditional USR2 + QUIT upgrade steps:
79 # Unicorn::HttpServer::START_CTX[0] = "/home/bofh/1.9.2/bin/unicorn"
81 :argv => ARGV.map { |arg| arg.dup },
84 # We favor ENV['PWD'] since it is (usually) symlink aware for Capistrano
86 START_CTX[:cwd] = begin
87 a = File.stat(pwd = ENV['PWD'])
88 b = File.stat(Dir.pwd)
89 a.ino == b.ino && a.dev == b.dev ? pwd : Dir.pwd
95 # Creates a working server on host:port (strange things happen if
96 # port isn't a Number). Use HttpServer::run to start the server and
97 # HttpServer.run.join to join the thread that's processing
98 # incoming requests on the socket.
99 def initialize(app, options = {})
101 @request = Unicorn::HttpRequest.new
103 options = options.dup
104 @ready_pipe = options.delete(:ready_pipe)
105 @init_listeners = options[:listeners] ? options[:listeners].dup : []
106 options[:use_defaults] = true
107 self.config = Unicorn::Configurator.new(options)
108 self.listener_opts = {}
110 # we try inheriting listeners first, so we bind them later.
111 # we don't write the pid file until we've bound listeners in case
112 # unicorn was started twice by mistake. Even though our #pid= method
113 # checks for stale/existing pid files, race conditions are still
114 # possible (and difficult/non-portable to avoid) and can be likely
115 # to clobber the pid if the second start was in quick succession
116 # after the first, so we rely on the listener binding to fail in
117 # that case. Some tests (in and outside of this source tree) and
118 # monitoring tools may also rely on pid files existing before we
119 # attempt to connect to the listener(s)
120 config.commit!(self, :skip => [:listeners, :pid])
124 # Runs the thing. Returns self so you can run join on it
127 # this pipe is used to wake us up from select(2) in #join when signals
128 # are trapped. See trap_deferred.
131 # setup signal handlers before writing pid file in case people get
132 # trigger happy and send signals as soon as the pid file exists.
133 # Note that signals don't actually get handled until the #join method
134 QUEUE_SIGS.each { |sig| trap(sig) { SIG_QUEUE << sig; awaken_master } }
135 trap(:CHLD) { awaken_master }
136 self.pid = config[:pid]
139 build_app! if preload_app
141 spawn_missing_workers
145 # replaces current listener set with +listeners+. This will
146 # close the socket if it will not exist in the new listener set
147 def listeners=(listeners)
148 cur_names, dead_names = [], []
149 listener_names.each do |name|
151 # mark unlinked sockets as dead so we can rebind them
152 (File.socket?(name) ? cur_names : dead_names) << name
157 set_names = listener_names(listeners)
158 dead_names.concat(cur_names - set_names).uniq!
160 LISTENERS.delete_if do |io|
161 if dead_names.include?(sock_name(io))
162 IO_PURGATORY.delete_if do |pio|
163 pio.fileno == io.fileno && (pio.close rescue nil).nil? # true
165 (io.close rescue nil).nil? # true
167 set_server_sockopt(io, listener_opts[sock_name(io)])
172 (set_names - cur_names).each { |addr| listen(addr) }
175 def stdout_path=(path); redirect_io($stdout, path); end
176 def stderr_path=(path); redirect_io($stderr, path); end
179 Unicorn::HttpRequest::DEFAULTS["rack.logger"] = @logger = obj
182 # sets the path for the PID file of the master process
185 if x = valid_pid?(path)
186 return path if pid && path == pid && x == $$
187 if x == reexec_pid && pid =~ /\.oldbin\z/
188 logger.warn("will not set pid=#{path} while reexec-ed "\
189 "child is running PID:#{x}")
192 raise ArgumentError, "Already running on PID:#{x} " \
193 "(or pid=#{path} is stale)"
196 unlink_pid_safe(pid) if pid
200 tmp = "#{File.dirname(path)}/#{rand}.#$$"
201 File.open(tmp, File::RDWR|File::CREAT|File::EXCL, 0644)
206 File.rename(fp.path, path)
212 # add a given address to the +listeners+ set, idempotently
213 # Allows workers to add a private, per-process listener via the
214 # after_fork hook. Very useful for debugging and testing.
215 # +:tries+ may be specified as an option for the number of times
216 # to retry, and +:delay+ may be specified as the time in seconds
217 # to delay between retries.
218 # A negative value for +:tries+ indicates the listen will be
219 # retried indefinitely, this is useful when workers belonging to
220 # different masters are spawned during a transparent upgrade.
221 def listen(address, opt = {}.merge(listener_opts[address] || {}))
222 address = config.expand_addr(address)
223 return if String === address && listener_names.include?(address)
225 delay = opt[:delay] || 0.5
226 tries = opt[:tries] || 5
228 io = bind_listen(address, opt)
229 unless Kgio::TCPServer === io || Kgio::UNIXServer === io
233 logger.info "listening on addr=#{sock_name(io)} fd=#{io.fileno}"
236 rescue Errno::EADDRINUSE => err
237 logger.error "adding listener failed addr=#{address} (in use)"
238 raise err if tries == 0
240 logger.error "retrying in #{delay} seconds " \
241 "(#{tries < 0 ? 'infinite' : tries} tries left)"
245 logger.fatal "error adding listener addr=#{address}"
250 # monitors children and receives signals forever
251 # (or until a termination signal is sent). This handles signals
252 # one-at-a-time time and we'll happily drop signals in case somebody
253 # is signalling us too often.
256 last_check = Time.now
259 logger.info "master process ready" # test_exec.rb relies on this message
261 @ready_pipe.syswrite($$.to_s)
262 @ready_pipe = @ready_pipe.close rescue nil
268 # avoid murdering workers after our master process (or the
269 # machine) comes out of suspend/hibernation
270 if (last_check + @timeout) >= (last_check = Time.now)
271 sleep_time = murder_lazy_workers
273 sleep_time = @timeout/2.0 + 1
274 @logger.debug("waiting #{sleep_time}s after suspend/hibernation")
276 maintain_worker_count if respawn
277 master_sleep(sleep_time)
278 when :QUIT # graceful shutdown
280 when :TERM, :INT # immediate shutdown
283 when :USR1 # rotate logs
284 logger.info "master reopening logs..."
285 Unicorn::Util.reopen_logs
286 logger.info "master done reopening logs"
287 kill_each_worker(:USR1)
288 when :USR2 # exec binary, stay alive in case something went wrong
291 if Unicorn::Configurator::RACKUP[:daemonized]
293 logger.info "gracefully stopping all workers"
294 kill_each_worker(:QUIT)
295 self.worker_processes = 0
297 logger.info "SIGWINCH ignored because we're not daemonized"
301 self.worker_processes += 1
303 self.worker_processes -= 1 if self.worker_processes > 0
306 if config.config_file
308 else # exec binary and exit if there's no config file
309 logger.info "config_file not present, reexecuting binary"
314 Unicorn.log_error(@logger, "master loop error", e)
316 stop # gracefully shutdown all workers on our way out
317 logger.info "master complete"
318 unlink_pid_safe(pid) if pid
321 # Terminates all workers, but does not exit master process
322 def stop(graceful = true)
324 limit = Time.now + timeout
325 until WORKERS.empty? || Time.now > limit
326 kill_each_worker(graceful ? :QUIT : :TERM)
330 kill_each_worker(:KILL)
334 Unicorn::HttpRequest.input_class.method_defined?(:rewind)
337 def rewindable_input=(bool)
338 Unicorn::HttpRequest.input_class = bool ?
339 Unicorn::TeeInput : Unicorn::StreamInput
342 def client_body_buffer_size
343 Unicorn::TeeInput.client_body_buffer_size
346 def client_body_buffer_size=(bytes)
347 Unicorn::TeeInput.client_body_buffer_size = bytes
350 def trust_x_forwarded
351 Unicorn::HttpParser.trust_x_forwarded?
354 def trust_x_forwarded=(bool)
355 Unicorn::HttpParser.trust_x_forwarded = bool
360 # wait for a signal hander to wake us up and then consume the pipe
361 def master_sleep(sec)
362 IO.select([ SELF_PIPE[0] ], nil, nil, sec) or return
363 SELF_PIPE[0].kgio_tryread(11)
367 SELF_PIPE[1].kgio_trywrite('.') # wakeup master process from select
370 # reaps all unreaped workers
373 wpid, status = Process.waitpid2(-1, Process::WNOHANG)
375 if reexec_pid == wpid
376 logger.error "reaped #{status.inspect} exec()-ed"
378 self.pid = pid.chomp('.oldbin') if pid
381 worker = WORKERS.delete(wpid) and worker.close rescue nil
382 m = "reaped #{status.inspect} worker=#{worker.nr rescue 'unknown'}"
383 status.success? ? logger.info(m) : logger.error(m)
390 # reexecutes the START_CTX with a new binary
394 Process.kill(0, reexec_pid)
395 logger.error "reexec-ed child already running PID:#{reexec_pid}"
403 old_pid = "#{pid}.oldbin"
405 self.pid = old_pid # clear the path for a new pid file
407 logger.error "old PID:#{valid_pid?(old_pid)} running with " \
408 "existing pid=#{old_pid}, refusing rexec"
411 logger.error "error writing pid=#{old_pid} #{e.class} #{e.message}"
416 self.reexec_pid = fork do
417 listener_fds = Hash[LISTENERS.map do |sock|
418 # IO#close_on_exec= will be available on any future version of
419 # Ruby that sets FD_CLOEXEC by default on new file descriptors
420 # ref: http://redmine.ruby-lang.org/issues/5041
421 sock.close_on_exec = false if sock.respond_to?(:close_on_exec=)
422 [ sock.fileno, sock ]
424 ENV['UNICORN_FD'] = listener_fds.keys.join(',')
425 Dir.chdir(START_CTX[:cwd])
426 cmd = [ START_CTX[0] ].concat(START_CTX[:argv])
428 # avoid leaking FDs we don't know about, but let before_exec
429 # unset FD_CLOEXEC, if anything else in the app eventually
430 # relies on FD inheritence.
431 (3..1024).each do |io|
432 next if listener_fds.include?(io)
433 io = IO.for_fd(io) rescue next
435 io.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
438 # exec(command, hash) works in at least 1.9.1+, but will only be
439 # required in 1.9.4/2.0.0 at earliest.
440 cmd << listener_fds if RUBY_VERSION >= "1.9.1"
441 logger.info "executing #{cmd.inspect} (in #{Dir.pwd})"
442 before_exec.call(self)
445 proc_name 'master (old)'
448 # forcibly terminate all workers that haven't checked in in timeout seconds. The timeout is implemented using an unlinked File
449 def murder_lazy_workers
450 next_sleep = @timeout - 1
452 WORKERS.dup.each_pair do |wpid, worker|
454 0 == tick and next # skip workers that haven't processed any clients
456 tmp = @timeout - diff
458 next_sleep > tmp and next_sleep = tmp
462 logger.error "worker=#{worker.nr} PID:#{wpid} timeout " \
463 "(#{diff}s > #{@timeout}s), killing"
464 kill_worker(:KILL, wpid) # take no prisoners for timeout violations
466 next_sleep <= 0 ? 1 : next_sleep
469 def after_fork_internal
470 @ready_pipe.close if @ready_pipe
471 Unicorn::Configurator::RACKUP.clear
472 @ready_pipe = @init_listeners = @before_exec = @before_fork = nil
474 srand # http://redmine.ruby-lang.org/issues/4338
476 # The OpenSSL PRNG is seeded with only the pid, and apps with frequently
477 # dying workers can recycle pids
478 OpenSSL::Random.seed(rand.to_s) if defined?(OpenSSL::Random)
481 def spawn_missing_workers
483 until (worker_nr += 1) == @worker_processes
484 WORKERS.value?(worker_nr) and next
485 worker = Worker.new(worker_nr)
486 before_fork.call(self, worker)
488 WORKERS[pid] = worker
496 @logger.error(e) rescue nil
500 def maintain_worker_count
501 (off = WORKERS.size - worker_processes) == 0 and return
502 off < 0 and return spawn_missing_workers
503 WORKERS.dup.each_pair { |wpid,w|
504 w.nr >= worker_processes and kill_worker(:QUIT, wpid) rescue nil
508 # if we get any error, try to write something back to the client
509 # assuming we haven't closed the socket, but don't get hung up
510 # if the socket is already closed or broken. We'll always ensure
511 # the socket is closed at the end of this function
512 def handle_error(client, e)
514 when EOFError,Errno::ECONNRESET,Errno::EPIPE,Errno::EINVAL,Errno::EBADF,
516 Unicorn::Const::ERROR_500_RESPONSE
517 when Unicorn::RequestURITooLongError
518 Unicorn::Const::ERROR_414_RESPONSE
519 when Unicorn::RequestEntityTooLargeError
520 Unicorn::Const::ERROR_413_RESPONSE
521 when Unicorn::HttpParserError # try to tell the client they're bad
522 Unicorn::Const::ERROR_400_RESPONSE
524 Unicorn.log_error(@logger, "app error", e)
525 Unicorn::Const::ERROR_500_RESPONSE
527 client.kgio_trywrite(msg)
532 # once a client is accepted, it is processed in its entirety here
533 # in 3 easy steps: read request, call app, write app response
534 def process_client(client)
535 status, headers, body = @app.call(env = @request.read(client))
537 if 100 == status.to_i
538 client.write(Unicorn::Const::EXPECT_100_RESPONSE)
539 env.delete(Unicorn::Const::HTTP_EXPECT)
540 status, headers, body = @app.call(env)
542 @request.headers? or headers = nil
543 http_response_write(client, status, headers, body)
544 client.shutdown # in case of fork() in Rack app
545 client.close # flush and uncork socket immediately, no keepalive
547 handle_error(client, e)
550 EXIT_SIGS = [ :QUIT, :TERM, :INT ]
551 WORKER_QUEUE_SIGS = QUEUE_SIGS - EXIT_SIGS
553 # gets rid of stuff the worker has no business keeping track of
554 # to free some resources and drops all sig handlers.
555 # traps for USR1, USR2, and HUP may be set in the after_fork Proc
557 def init_worker_process(worker)
558 # we'll re-trap :QUIT later for graceful shutdown iff we accept clients
559 EXIT_SIGS.each { |sig| trap(sig) { exit!(0) } }
560 exit!(0) if (SIG_QUEUE & EXIT_SIGS)[0]
561 WORKER_QUEUE_SIGS.each { |sig| trap(sig, nil) }
562 trap(:CHLD, 'DEFAULT')
564 proc_name "worker[#{worker.nr}]"
568 LISTENERS.each { |sock| sock.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) }
569 after_fork.call(self, worker) # can drop perms
570 worker.user(*user) if user.kind_of?(Array) && ! worker.switched
571 self.timeout /= 2.0 # halve it for select()
573 build_app! unless preload_app
575 @after_fork = @listener_opts = @orig_app = nil
578 def reopen_worker_logs(worker_nr)
579 logger.info "worker=#{worker_nr} reopening logs..."
580 Unicorn::Util.reopen_logs
581 logger.info "worker=#{worker_nr} done reopening logs"
584 logger.error(e) rescue nil
585 exit!(77) # EX_NOPERM in sysexits.h
588 # runs inside each forked worker, this sits around and waits
589 # for connections and doesn't die until the parent dies (or is
590 # given a INT, QUIT, or TERM signal)
591 def worker_loop(worker)
593 init_worker_process(worker)
594 nr = 0 # this becomes negative if we need to reopen logs
598 # closing anything we IO.select on will raise EBADF
599 trap(:USR1) { nr = -65536; SELF_PIPE[0].close rescue nil }
600 trap(:QUIT) { worker = nil; LISTENERS.each { |s| s.close rescue nil }.clear }
601 logger.info "worker=#{worker.nr} ready"
604 nr < 0 and reopen_worker_logs(worker.nr)
607 worker.tick = Time.now.to_i
608 while sock = ready.shift
609 if client = sock.kgio_tryaccept
610 process_client(client)
612 worker.tick = Time.now.to_i
617 # make the following bet: if we accepted clients this round,
618 # we're probably reasonably busy, so avoid calling select()
619 # and do a speculative non-blocking accept() on ready listeners
620 # before we sleep again in select().
621 unless nr == 0 # (nr < 0) => reopen logs (unlikely)
626 ppid == Process.ppid or return
628 # timeout used so we can detect parent death:
629 worker.tick = Time.now.to_i
630 ret = IO.select(l, nil, SELF_PIPE, @timeout) and ready = ret[0]
632 redo if nr < 0 && (Errno::EBADF === e || IOError === e) # reopen logs
633 Unicorn.log_error(@logger, "listen loop error", e) if worker
637 # delivers a signal to a worker and fails gracefully if the worker
638 # is no longer running.
639 def kill_worker(signal, wpid)
640 Process.kill(signal, wpid)
642 worker = WORKERS.delete(wpid) and worker.close rescue nil
645 # delivers a signal to each worker
646 def kill_each_worker(signal)
647 WORKERS.keys.each { |wpid| kill_worker(signal, wpid) }
650 # unlinks a PID file at given +path+ if it contains the current PID
651 # still potentially racy without locking the directory (which is
652 # non-portable and may interact badly with other programs), but the
653 # window for hitting the race condition is small
654 def unlink_pid_safe(path)
655 (File.read(path).to_i == $$ and File.unlink(path)) rescue nil
658 # returns a PID if a given path contains a non-stale PID file,
661 wpid = File.read(path).to_i
663 Process.kill(0, wpid)
666 logger.info "pid=#{path} possibly stale, got EPERM signalling PID:#{wpid}"
668 rescue Errno::ESRCH, Errno::ENOENT
669 # don't unlink stale pid files, racy without non-portable locking...
674 logger.info "reloading config_file=#{config.config_file}"
675 config[:listeners].replace(@init_listeners)
678 kill_each_worker(:QUIT)
679 Unicorn::Util.reopen_logs
681 build_app! if preload_app
682 logger.info "done reloading config_file=#{config.config_file}"
683 rescue StandardError, LoadError, SyntaxError => e
684 Unicorn.log_error(@logger,
685 "error reloading config_file=#{config.config_file}", e)
686 self.app = loaded_app
689 # returns an array of string names for the given listener array
690 def listener_names(listeners = LISTENERS)
691 listeners.map { |io| sock_name(io) }
695 if app.respond_to?(:arity) && app.arity == 0
696 if defined?(Gem) && Gem.respond_to?(:refresh)
697 logger.info "Refreshing Gem list"
705 $0 = ([ File.basename(START_CTX[0]), tag
706 ]).concat(START_CTX[:argv]).join(' ')
709 def redirect_io(io, path)
710 File.open(path, 'ab') { |fp| io.reopen(fp) } if path
715 SELF_PIPE.each { |io| io.close rescue nil }
716 SELF_PIPE.replace(Kgio::Pipe.new)
717 SELF_PIPE.each { |io| io.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) }
720 def inherit_listeners!
721 # inherit sockets from parents, they need to be plain Socket objects
722 # before they become Kgio::UNIXServer or Kgio::TCPServer
723 inherited = ENV['UNICORN_FD'].to_s.split(/,/).map do |fd|
724 io = Socket.for_fd(fd.to_i)
725 set_server_sockopt(io, listener_opts[sock_name(io)])
727 logger.info "inherited addr=#{sock_name(io)} fd=#{fd}"
731 config_listeners = config[:listeners].dup
732 LISTENERS.replace(inherited)
734 # we start out with generic Socket objects that get cast to either
735 # Kgio::TCPServer or Kgio::UNIXServer objects; but since the Socket
736 # objects share the same OS-level file descriptor as the higher-level
737 # *Server objects; we need to prevent Socket objects from being
739 config_listeners -= listener_names
740 if config_listeners.empty? && LISTENERS.empty?
741 config_listeners << Unicorn::Const::DEFAULT_LISTEN
742 @init_listeners << Unicorn::Const::DEFAULT_LISTEN
743 START_CTX[:argv] << "-l#{Unicorn::Const::DEFAULT_LISTEN}"
745 NEW_LISTENERS.replace(config_listeners)
748 # call only after calling inherit_listeners!
749 # This binds any listeners we did NOT inherit from the parent
750 def bind_new_listeners!
751 NEW_LISTENERS.each { |addr| listen(addr) }
752 raise ArgumentError, "no listeners" if LISTENERS.empty?