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
21 attr_reader :pid, :logger
22 include Unicorn::SocketHelper
23 include Unicorn::HttpResponse
24 include Unicorn::SSLServer
26 # backwards compatibility with 1.x
27 Worker = Unicorn::Worker
29 # all bound listener sockets
32 # listeners we have yet to bind
35 # This hash maps PIDs to Workers
38 # We use SELF_PIPE differently in the master and worker processes:
40 # * The master process never closes or reinitializes this once
41 # initialized. Signal handlers in the master process will write to
42 # it to wake up the master from IO.select in exactly the same manner
43 # djb describes in http://cr.yp.to/docs/selfpipe.html
45 # * The workers immediately close the pipe they inherit from the
46 # master and replace it with a new pipe after forking. This new
47 # pipe is also used to wakeup from IO.select from inside (worker)
48 # signal handlers. However, workers *close* the pipe descriptors in
49 # the signal handlers to raise EBADF in IO.select instead of writing
50 # like we do in the master. We cannot easily use the reader set for
51 # IO.select because LISTENERS is already that set, and it's extra
52 # work (and cycles) to distinguish the pipe FD from the reader set
53 # once IO.select returns. So we're lazy and just close the pipe when
54 # a (rare) signal arrives in the worker and reinitialize the pipe later.
57 # signal queue used for self-piping
60 # list of signals we care about and trap in master.
61 QUEUE_SIGS = [ :WINCH, :QUIT, :INT, :TERM, :USR1, :USR2, :HUP, :TTIN, :TTOU ]
64 # We populate this at startup so we can figure out how to reexecute
65 # and upgrade the currently running instance of Unicorn
66 # This Hash is considered a stable interface and changing its contents
67 # will allow you to switch between different installations of Unicorn
68 # or even different installations of the same applications without
69 # downtime. Keys of this constant Hash are described as follows:
71 # * 0 - the path to the unicorn/unicorn_rails executable
72 # * :argv - a deep copy of the ARGV array the executable originally saw
73 # * :cwd - the working directory of the application, this is where
74 # you originally started Unicorn.
76 # To change your unicorn executable to a different path without downtime,
77 # you can set the following in your Unicorn config file, HUP and then
78 # continue with the traditional USR2 + QUIT upgrade steps:
80 # Unicorn::HttpServer::START_CTX[0] = "/home/bofh/1.9.2/bin/unicorn"
82 :argv => ARGV.map { |arg| arg.dup },
85 # We favor ENV['PWD'] since it is (usually) symlink aware for Capistrano
87 START_CTX[:cwd] = begin
88 a = File.stat(pwd = ENV['PWD'])
89 b = File.stat(Dir.pwd)
90 a.ino == b.ino && a.dev == b.dev ? pwd : Dir.pwd
96 # Creates a working server on host:port (strange things happen if
97 # port isn't a Number). Use HttpServer::run to start the server and
98 # HttpServer.run.join to join the thread that's processing
99 # incoming requests on the socket.
100 def initialize(app, options = {})
102 @request = Unicorn::HttpRequest.new
104 options = options.dup
105 @ready_pipe = options.delete(:ready_pipe)
106 @init_listeners = options[:listeners] ? options[:listeners].dup : []
107 options[:use_defaults] = true
108 self.config = Unicorn::Configurator.new(options)
109 self.listener_opts = {}
111 # we try inheriting listeners first, so we bind them later.
112 # we don't write the pid file until we've bound listeners in case
113 # unicorn was started twice by mistake. Even though our #pid= method
114 # checks for stale/existing pid files, race conditions are still
115 # possible (and difficult/non-portable to avoid) and can be likely
116 # to clobber the pid if the second start was in quick succession
117 # after the first, so we rely on the listener binding to fail in
118 # that case. Some tests (in and outside of this source tree) and
119 # monitoring tools may also rely on pid files existing before we
120 # attempt to connect to the listener(s)
121 config.commit!(self, :skip => [:listeners, :pid])
125 # Runs the thing. Returns self so you can run join on it
128 # this pipe is used to wake us up from select(2) in #join when signals
129 # are trapped. See trap_deferred.
132 # setup signal handlers before writing pid file in case people get
133 # trigger happy and send signals as soon as the pid file exists.
134 # Note that signals don't actually get handled until the #join method
135 QUEUE_SIGS.each { |sig| trap(sig) { SIG_QUEUE << sig; awaken_master } }
136 trap(:CHLD) { awaken_master }
137 self.pid = config[:pid]
140 build_app! if preload_app
142 spawn_missing_workers
146 # replaces current listener set with +listeners+. This will
147 # close the socket if it will not exist in the new listener set
148 def listeners=(listeners)
149 cur_names, dead_names = [], []
150 listener_names.each do |name|
152 # mark unlinked sockets as dead so we can rebind them
153 (File.socket?(name) ? cur_names : dead_names) << name
158 set_names = listener_names(listeners)
159 dead_names.concat(cur_names - set_names).uniq!
161 LISTENERS.delete_if do |io|
162 if dead_names.include?(sock_name(io))
163 IO_PURGATORY.delete_if do |pio|
164 pio.fileno == io.fileno && (pio.close rescue nil).nil? # true
166 (io.close rescue nil).nil? # true
168 set_server_sockopt(io, listener_opts[sock_name(io)])
173 (set_names - cur_names).each { |addr| listen(addr) }
176 def stdout_path=(path); redirect_io($stdout, path); end
177 def stderr_path=(path); redirect_io($stderr, path); end
180 Unicorn::HttpRequest::DEFAULTS["rack.logger"] = @logger = obj
183 # sets the path for the PID file of the master process
186 if x = valid_pid?(path)
187 return path if pid && path == pid && x == $$
188 if x == reexec_pid && pid =~ /\.oldbin\z/
189 logger.warn("will not set pid=#{path} while reexec-ed "\
190 "child is running PID:#{x}")
193 raise ArgumentError, "Already running on PID:#{x} " \
194 "(or pid=#{path} is stale)"
197 unlink_pid_safe(pid) if pid
201 tmp = "#{File.dirname(path)}/#{rand}.#$$"
202 File.open(tmp, File::RDWR|File::CREAT|File::EXCL, 0644)
207 File.rename(fp.path, path)
213 # add a given address to the +listeners+ set, idempotently
214 # Allows workers to add a private, per-process listener via the
215 # after_fork hook. Very useful for debugging and testing.
216 # +:tries+ may be specified as an option for the number of times
217 # to retry, and +:delay+ may be specified as the time in seconds
218 # to delay between retries.
219 # A negative value for +:tries+ indicates the listen will be
220 # retried indefinitely, this is useful when workers belonging to
221 # different masters are spawned during a transparent upgrade.
222 def listen(address, opt = {}.merge(listener_opts[address] || {}))
223 address = config.expand_addr(address)
224 return if String === address && listener_names.include?(address)
226 delay = opt[:delay] || 0.5
227 tries = opt[:tries] || 5
229 io = bind_listen(address, opt)
230 unless Kgio::TCPServer === io || Kgio::UNIXServer === io
234 logger.info "listening on addr=#{sock_name(io)} fd=#{io.fileno}"
237 rescue Errno::EADDRINUSE => err
238 logger.error "adding listener failed addr=#{address} (in use)"
239 raise err if tries == 0
241 logger.error "retrying in #{delay} seconds " \
242 "(#{tries < 0 ? 'infinite' : tries} tries left)"
246 logger.fatal "error adding listener addr=#{address}"
251 # monitors children and receives signals forever
252 # (or until a termination signal is sent). This handles signals
253 # one-at-a-time time and we'll happily drop signals in case somebody
254 # is signalling us too often.
257 last_check = Time.now
260 logger.info "master process ready" # test_exec.rb relies on this message
262 @ready_pipe.syswrite($$.to_s)
263 @ready_pipe = @ready_pipe.close rescue nil
269 # avoid murdering workers after our master process (or the
270 # machine) comes out of suspend/hibernation
271 if (last_check + @timeout) >= (last_check = Time.now)
272 sleep_time = murder_lazy_workers
274 sleep_time = @timeout/2.0 + 1
275 @logger.debug("waiting #{sleep_time}s after suspend/hibernation")
277 maintain_worker_count if respawn
278 master_sleep(sleep_time)
279 when :QUIT # graceful shutdown
281 when :TERM, :INT # immediate shutdown
284 when :USR1 # rotate logs
285 logger.info "master reopening logs..."
286 Unicorn::Util.reopen_logs
287 logger.info "master done reopening logs"
288 kill_each_worker(:USR1)
289 when :USR2 # exec binary, stay alive in case something went wrong
292 if Unicorn::Configurator::RACKUP[:daemonized]
294 logger.info "gracefully stopping all workers"
295 kill_each_worker(:QUIT)
296 self.worker_processes = 0
298 logger.info "SIGWINCH ignored because we're not daemonized"
302 self.worker_processes += 1
304 self.worker_processes -= 1 if self.worker_processes > 0
307 if config.config_file
309 else # exec binary and exit if there's no config file
310 logger.info "config_file not present, reexecuting binary"
315 Unicorn.log_error(@logger, "master loop error", e)
317 stop # gracefully shutdown all workers on our way out
318 logger.info "master complete"
319 unlink_pid_safe(pid) if pid
322 # Terminates all workers, but does not exit master process
323 def stop(graceful = true)
325 limit = Time.now + timeout
326 until WORKERS.empty? || Time.now > limit
327 kill_each_worker(graceful ? :QUIT : :TERM)
331 kill_each_worker(:KILL)
335 Unicorn::HttpRequest.input_class.method_defined?(:rewind)
338 def rewindable_input=(bool)
339 Unicorn::HttpRequest.input_class = bool ?
340 Unicorn::TeeInput : Unicorn::StreamInput
343 def client_body_buffer_size
344 Unicorn::TeeInput.client_body_buffer_size
347 def client_body_buffer_size=(bytes)
348 Unicorn::TeeInput.client_body_buffer_size = bytes
351 def trust_x_forwarded
352 Unicorn::HttpParser.trust_x_forwarded?
355 def trust_x_forwarded=(bool)
356 Unicorn::HttpParser.trust_x_forwarded = bool
359 def check_client_connection
360 Unicorn::HttpRequest.check_client_connection
363 def check_client_connection=(bool)
364 Unicorn::HttpRequest.check_client_connection = bool
369 # wait for a signal hander to wake us up and then consume the pipe
370 def master_sleep(sec)
371 IO.select([ SELF_PIPE[0] ], nil, nil, sec) or return
372 SELF_PIPE[0].kgio_tryread(11)
376 SELF_PIPE[1].kgio_trywrite('.') # wakeup master process from select
379 # reaps all unreaped workers
382 wpid, status = Process.waitpid2(-1, Process::WNOHANG)
384 if reexec_pid == wpid
385 logger.error "reaped #{status.inspect} exec()-ed"
387 self.pid = pid.chomp('.oldbin') if pid
390 worker = WORKERS.delete(wpid) and worker.close rescue nil
391 m = "reaped #{status.inspect} worker=#{worker.nr rescue 'unknown'}"
392 status.success? ? logger.info(m) : logger.error(m)
399 # reexecutes the START_CTX with a new binary
403 Process.kill(0, reexec_pid)
404 logger.error "reexec-ed child already running PID:#{reexec_pid}"
412 old_pid = "#{pid}.oldbin"
414 self.pid = old_pid # clear the path for a new pid file
416 logger.error "old PID:#{valid_pid?(old_pid)} running with " \
417 "existing pid=#{old_pid}, refusing rexec"
420 logger.error "error writing pid=#{old_pid} #{e.class} #{e.message}"
425 self.reexec_pid = fork do
426 listener_fds = Hash[LISTENERS.map do |sock|
427 # IO#close_on_exec= will be available on any future version of
428 # Ruby that sets FD_CLOEXEC by default on new file descriptors
429 # ref: http://redmine.ruby-lang.org/issues/5041
430 sock.close_on_exec = false if sock.respond_to?(:close_on_exec=)
431 [ sock.fileno, sock ]
433 ENV['UNICORN_FD'] = listener_fds.keys.join(',')
434 Dir.chdir(START_CTX[:cwd])
435 cmd = [ START_CTX[0] ].concat(START_CTX[:argv])
437 # avoid leaking FDs we don't know about, but let before_exec
438 # unset FD_CLOEXEC, if anything else in the app eventually
439 # relies on FD inheritence.
440 (3..1024).each do |io|
441 next if listener_fds.include?(io)
442 io = IO.for_fd(io) rescue next
444 io.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
447 # exec(command, hash) works in at least 1.9.1+, but will only be
448 # required in 1.9.4/2.0.0 at earliest.
449 cmd << listener_fds if RUBY_VERSION >= "1.9.1"
450 logger.info "executing #{cmd.inspect} (in #{Dir.pwd})"
451 before_exec.call(self)
454 proc_name 'master (old)'
457 # forcibly terminate all workers that haven't checked in in timeout seconds. The timeout is implemented using an unlinked File
458 def murder_lazy_workers
459 next_sleep = @timeout - 1
461 WORKERS.dup.each_pair do |wpid, worker|
463 0 == tick and next # skip workers that haven't processed any clients
465 tmp = @timeout - diff
467 next_sleep > tmp and next_sleep = tmp
471 logger.error "worker=#{worker.nr} PID:#{wpid} timeout " \
472 "(#{diff}s > #{@timeout}s), killing"
473 kill_worker(:KILL, wpid) # take no prisoners for timeout violations
475 next_sleep <= 0 ? 1 : next_sleep
478 def after_fork_internal
479 @ready_pipe.close if @ready_pipe
480 Unicorn::Configurator::RACKUP.clear
481 @ready_pipe = @init_listeners = @before_exec = @before_fork = nil
483 srand # http://redmine.ruby-lang.org/issues/4338
485 # The OpenSSL PRNG is seeded with only the pid, and apps with frequently
486 # dying workers can recycle pids
487 OpenSSL::Random.seed(rand.to_s) if defined?(OpenSSL::Random)
490 def spawn_missing_workers
492 until (worker_nr += 1) == @worker_processes
493 WORKERS.value?(worker_nr) and next
494 worker = Worker.new(worker_nr)
495 before_fork.call(self, worker)
497 WORKERS[pid] = worker
505 @logger.error(e) rescue nil
509 def maintain_worker_count
510 (off = WORKERS.size - worker_processes) == 0 and return
511 off < 0 and return spawn_missing_workers
512 WORKERS.dup.each_pair { |wpid,w|
513 w.nr >= worker_processes and kill_worker(:QUIT, wpid) rescue nil
517 # if we get any error, try to write something back to the client
518 # assuming we haven't closed the socket, but don't get hung up
519 # if the socket is already closed or broken. We'll always ensure
520 # the socket is closed at the end of this function
521 def handle_error(client, e)
523 when EOFError,Errno::ECONNRESET,Errno::EPIPE,Errno::EINVAL,Errno::EBADF,
526 when Unicorn::RequestURITooLongError
528 when Unicorn::RequestEntityTooLargeError
530 when Unicorn::HttpParserError # try to tell the client they're bad
533 Unicorn.log_error(@logger, "app error", e)
536 client.kgio_trywrite(err_response(code, @request.response_start_sent))
541 def expect_100_response
542 if @request.response_start_sent
543 Unicorn::Const::EXPECT_100_RESPONSE_SUFFIXED
545 Unicorn::Const::EXPECT_100_RESPONSE
549 # once a client is accepted, it is processed in its entirety here
550 # in 3 easy steps: read request, call app, write app response
551 def process_client(client)
552 status, headers, body = @app.call(env = @request.read(client))
554 if 100 == status.to_i
555 client.write(expect_100_response)
556 env.delete(Unicorn::Const::HTTP_EXPECT)
557 status, headers, body = @app.call(env)
559 @request.headers? or headers = nil
560 http_response_write(client, status, headers, body,
561 @request.response_start_sent)
562 client.shutdown # in case of fork() in Rack app
563 client.close # flush and uncork socket immediately, no keepalive
565 handle_error(client, e)
568 EXIT_SIGS = [ :QUIT, :TERM, :INT ]
569 WORKER_QUEUE_SIGS = QUEUE_SIGS - EXIT_SIGS
571 # gets rid of stuff the worker has no business keeping track of
572 # to free some resources and drops all sig handlers.
573 # traps for USR1, USR2, and HUP may be set in the after_fork Proc
575 def init_worker_process(worker)
576 # we'll re-trap :QUIT later for graceful shutdown iff we accept clients
577 EXIT_SIGS.each { |sig| trap(sig) { exit!(0) } }
578 exit!(0) if (SIG_QUEUE & EXIT_SIGS)[0]
579 WORKER_QUEUE_SIGS.each { |sig| trap(sig, nil) }
580 trap(:CHLD, 'DEFAULT')
582 proc_name "worker[#{worker.nr}]"
586 LISTENERS.each { |sock| sock.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) }
587 after_fork.call(self, worker) # can drop perms
588 worker.user(*user) if user.kind_of?(Array) && ! worker.switched
589 self.timeout /= 2.0 # halve it for select()
591 build_app! unless preload_app
593 @after_fork = @listener_opts = @orig_app = nil
596 def reopen_worker_logs(worker_nr)
597 logger.info "worker=#{worker_nr} reopening logs..."
598 Unicorn::Util.reopen_logs
599 logger.info "worker=#{worker_nr} done reopening logs"
602 logger.error(e) rescue nil
603 exit!(77) # EX_NOPERM in sysexits.h
606 # runs inside each forked worker, this sits around and waits
607 # for connections and doesn't die until the parent dies (or is
608 # given a INT, QUIT, or TERM signal)
609 def worker_loop(worker)
611 init_worker_process(worker)
612 nr = 0 # this becomes negative if we need to reopen logs
616 # closing anything we IO.select on will raise EBADF
617 trap(:USR1) { nr = -65536; SELF_PIPE[0].close rescue nil }
618 trap(:QUIT) { worker = nil; LISTENERS.each { |s| s.close rescue nil }.clear }
619 logger.info "worker=#{worker.nr} ready"
622 nr < 0 and reopen_worker_logs(worker.nr)
625 worker.tick = Time.now.to_i
626 while sock = ready.shift
627 if client = sock.kgio_tryaccept
628 process_client(client)
630 worker.tick = Time.now.to_i
635 # make the following bet: if we accepted clients this round,
636 # we're probably reasonably busy, so avoid calling select()
637 # and do a speculative non-blocking accept() on ready listeners
638 # before we sleep again in select().
639 unless nr == 0 # (nr < 0) => reopen logs (unlikely)
644 ppid == Process.ppid or return
646 # timeout used so we can detect parent death:
647 worker.tick = Time.now.to_i
648 ret = IO.select(l, nil, SELF_PIPE, @timeout) and ready = ret[0]
650 redo if nr < 0 && (Errno::EBADF === e || IOError === e) # reopen logs
651 Unicorn.log_error(@logger, "listen loop error", e) if worker
655 # delivers a signal to a worker and fails gracefully if the worker
656 # is no longer running.
657 def kill_worker(signal, wpid)
658 Process.kill(signal, wpid)
660 worker = WORKERS.delete(wpid) and worker.close rescue nil
663 # delivers a signal to each worker
664 def kill_each_worker(signal)
665 WORKERS.keys.each { |wpid| kill_worker(signal, wpid) }
668 # unlinks a PID file at given +path+ if it contains the current PID
669 # still potentially racy without locking the directory (which is
670 # non-portable and may interact badly with other programs), but the
671 # window for hitting the race condition is small
672 def unlink_pid_safe(path)
673 (File.read(path).to_i == $$ and File.unlink(path)) rescue nil
676 # returns a PID if a given path contains a non-stale PID file,
679 wpid = File.read(path).to_i
681 Process.kill(0, wpid)
684 logger.info "pid=#{path} possibly stale, got EPERM signalling PID:#{wpid}"
686 rescue Errno::ESRCH, Errno::ENOENT
687 # don't unlink stale pid files, racy without non-portable locking...
692 logger.info "reloading config_file=#{config.config_file}"
693 config[:listeners].replace(@init_listeners)
696 kill_each_worker(:QUIT)
697 Unicorn::Util.reopen_logs
699 build_app! if preload_app
700 logger.info "done reloading config_file=#{config.config_file}"
701 rescue StandardError, LoadError, SyntaxError => e
702 Unicorn.log_error(@logger,
703 "error reloading config_file=#{config.config_file}", e)
704 self.app = loaded_app
707 # returns an array of string names for the given listener array
708 def listener_names(listeners = LISTENERS)
709 listeners.map { |io| sock_name(io) }
713 if app.respond_to?(:arity) && app.arity == 0
714 if defined?(Gem) && Gem.respond_to?(:refresh)
715 logger.info "Refreshing Gem list"
723 $0 = ([ File.basename(START_CTX[0]), tag
724 ]).concat(START_CTX[:argv]).join(' ')
727 def redirect_io(io, path)
728 File.open(path, 'ab') { |fp| io.reopen(fp) } if path
733 SELF_PIPE.each { |io| io.close rescue nil }
734 SELF_PIPE.replace(Kgio::Pipe.new)
735 SELF_PIPE.each { |io| io.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) }
738 def inherit_listeners!
739 # inherit sockets from parents, they need to be plain Socket objects
740 # before they become Kgio::UNIXServer or Kgio::TCPServer
741 inherited = ENV['UNICORN_FD'].to_s.split(/,/).map do |fd|
742 io = Socket.for_fd(fd.to_i)
743 set_server_sockopt(io, listener_opts[sock_name(io)])
745 logger.info "inherited addr=#{sock_name(io)} fd=#{fd}"
749 config_listeners = config[:listeners].dup
750 LISTENERS.replace(inherited)
752 # we start out with generic Socket objects that get cast to either
753 # Kgio::TCPServer or Kgio::UNIXServer objects; but since the Socket
754 # objects share the same OS-level file descriptor as the higher-level
755 # *Server objects; we need to prevent Socket objects from being
757 config_listeners -= listener_names
758 if config_listeners.empty? && LISTENERS.empty?
759 config_listeners << Unicorn::Const::DEFAULT_LISTEN
760 @init_listeners << Unicorn::Const::DEFAULT_LISTEN
761 START_CTX[:argv] << "-l#{Unicorn::Const::DEFAULT_LISTEN}"
763 NEW_LISTENERS.replace(config_listeners)
766 # call only after calling inherit_listeners!
767 # This binds any listeners we did NOT inherit from the parent
768 def bind_new_listeners!
769 NEW_LISTENERS.each { |addr| listen(addr) }
770 raise ArgumentError, "no listeners" if LISTENERS.empty?