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| | # Copyright (C) 2013-2016 all contributors <yahns-public@yhbt.net>
# License: GPL-3.0+ (https://www.gnu.org/licenses/gpl-3.0.txt)
# frozen_string_literal: true
require_relative 'queue_quitter'
require_relative 'tcp_server'
require_relative 'unix_server'
class Yahns::Server # :nodoc:
QUEUE_SIGS = [ :WINCH, :QUIT, :INT, :TERM, :USR1, :USR2, :HUP, :TTIN, :TTOU,
:CHLD ]
attr_accessor :daemon_pipe
attr_accessor :logger
attr_writer :user
attr_writer :before_exec
attr_writer :worker_processes
attr_writer :shutdown_timeout
attr_writer :atfork_prepare
attr_writer :atfork_parent
attr_writer :atfork_child
include Yahns::SocketHelper
def initialize(config)
@shutdown_expire = nil
@shutdown_timeout = nil
@reexec_pid = 0
@daemon_pipe = nil # writable IO or true
@config = config
@workers = {} # pid -> workers
@sig_queue = [] # nil in forked workers
@logger = Logger.new($stderr)
@sev = Yahns::Sigevent.new
@listeners = []
@pid = nil
@worker_processes = nil
@before_exec = nil
@atfork_prepare = @atfork_parent = @atfork_child = nil
@user = nil
@queues = []
@wthr = []
end
def sqwakeup(sig)
@sig_queue << sig
@sev.sev_signal
end
def start
@config.commit!(self)
inherit_listeners!
# we try inheriting listeners first, so we bind them later.
# we don't write the pid file until we've bound listeners in case
# yahns was started twice by mistake.
# setup signal handlers before writing pid file in case people get
# trigger happy and send signals as soon as the pid file exists.
QUEUE_SIGS.each { |sig| trap(sig) { sqwakeup(sig) } }
bind_new_listeners!
self.pid = @config.value(:pid) # write pid file
if @worker_processes
require_relative 'server_mp'
extend Yahns::ServerMP
else
switch_user(*@user) if @user
end
self
end
def switch_user(user, group = nil)
# we do not protect the caller, checking Process.euid == 0 is
# insufficient because modern systems have fine-grained
# capabilities. Let the caller handle any and all errors.
uid = Etc.getpwnam(user).uid
gid = Etc.getgrnam(group).gid if group
Yahns::Log.chown_all(uid, gid)
if gid && Process.egid != gid
Process.initgroups(user, gid)
Process::GID.change_privilege(gid)
end
Process.euid != uid and Process::UID.change_privilege(uid)
end
def drop_acceptors
@listeners.delete_if(&:ac_quit)
end
# replaces current listener set with +listeners+. This will
# close the socket if it will not exist in the new listener set
def listeners=(listeners)
cur_names, dead_names = [], []
listener_names.each do |name|
if ?/ == name[0]
# mark unlinked sockets as dead so we can rebind them
(File.socket?(name) ? cur_names : dead_names) << name
else
cur_names << name
end
end
set_names = listener_names(listeners)
dead_names.concat(cur_names - set_names).uniq!
dying = []
@listeners.delete_if do |io|
if dead_names.include?(sock_name(io))
if io.ac_quit
true
else
dying << io
false
end
else
set_server_sockopt(io, sock_opts(io))
false
end
end
dying.delete_if(&:ac_quit) while dying[0]
(set_names - cur_names).each { |addr| listen(addr) }
end
def clobber_pid(path)
unlink_pid_safe(@pid) if @pid
if path
fp = begin
tmp = "#{File.dirname(path)}/#{rand}.#$$"
File.open(tmp, File::RDWR|File::CREAT|File::EXCL, 0644)
rescue Errno::EEXIST
retry
end
fp.syswrite("#$$\n")
File.rename(fp.path, path)
fp.close
end
end
# sets the path for the PID file of the master process
def pid=(path)
if path
if x = valid_pid?(path)
return path if @pid && path == @pid && x == $$
if x == @reexec_pid && @pid =~ /\.oldbin\z/
@logger.warn("will not set pid=#{path} while reexec-ed "\
"child is running PID:#{x}")
return
end
raise ArgumentError, "Already running on PID:#{x} " \
"(or pid=#{path} is stale)"
end
end
# rename the old pid if possible
if @pid && path
begin
File.rename(@pid, path)
rescue Errno::ENOENT, Errno::EXDEV
# a user may have accidentally removed the original,
# obviously cross-FS renames don't work, either.
clobber_pid(path)
end
else
clobber_pid(path)
end
@pid = path
end
# add a given address to the +listeners+ set, idempotently
# Allows workers to add a private, per-process listener via the
# after_fork hook. Very useful for debugging and testing.
# +:tries+ may be specified as an option for the number of times
# to retry, and +:delay+ may be specified as the time in seconds
# to delay between retries.
# A negative value for +:tries+ indicates the listen will be
# retried indefinitely, this is useful when workers belonging to
# different masters are spawned during a transparent upgrade.
def listen(address)
address = @config.expand_addr(address)
return if String === address && listener_names.include?(address)
delay = 0.5
tries = 5
begin
opts = sock_opts(address)
io = bind_listen(address, opts)
io = server_cast(io, opts) unless io.class.name.start_with?('Yahns::')
@logger.info "listening on addr=#{sock_name(io)} fd=#{io.fileno}"
@listeners << io
io
rescue Errno::EADDRINUSE => err
if tries == 0
@logger.error "adding listener failed addr=#{address} (in use)"
raise err
end
tries -= 1
@logger.warn "retrying in #{delay} seconds " \
"(#{tries < 0 ? 'infinite' : tries} tries left)"
sleep(delay)
retry
rescue => err
@logger.fatal "error adding listener addr=#{address}"
raise err
end
end
def daemon_ready
@daemon_pipe.respond_to?(:syswrite) or return
begin
@daemon_pipe.syswrite("#$$")
rescue => e
@logger.warn("grandparent died too soon?: #{e.message} (#{e.class})")
end
@daemon_pipe.close
@daemon_pipe = true # for SIGWINCH
end
# reexecutes the Yahns::START with a new binary
def reexec
if @reexec_pid > 0
begin
Process.kill(0, @reexec_pid)
@logger.error "reexec-ed child already running PID:#@reexec_pid"
return
rescue Errno::ESRCH
@reexec_pid = 0
end
end
if @pid
old_pid = "#@pid.oldbin"
begin
self.pid = old_pid # clear the path for a new pid file
rescue ArgumentError
@logger.error "old PID:#{valid_pid?(old_pid)} running with " \
"existing pid=#{old_pid}, refusing rexec"
return
rescue => e
@logger.error "error writing pid=#{old_pid} #{e.class} #{e.message}"
return
end
end
opt = {}
@listeners.each { |sock| opt[sock.fileno] = sock }
env = ENV.to_hash
env['YAHNS_FD'] = opt.keys.join(',')
opt[:close_others] = true
cmd = [ Yahns::START[0] ].concat(Yahns::START[:argv])
dir = @config.value(:working_directory) || Yahns::START[:cwd]
@logger.info "spawning #{cmd.inspect} (in #{dir})"
@reexec_pid = if @before_exec
fork do
Dir.chdir(dir)
@before_exec.call(cmd)
exec(env, *cmd, opt)
end
else
opt[:chdir] = dir
spawn(env, *cmd, opt)
end
end
# unlinks a PID file at given +path+ if it contains the current PID
# still potentially racy without locking the directory (which is
# non-portable and may interact badly with other programs), but the
# window for hitting the race condition is small
def unlink_pid_safe(path)
(File.read(path).to_i == $$ and File.unlink(path)) rescue nil
end
# returns a PID if a given path contains a non-stale PID file,
# nil otherwise.
def valid_pid?(path)
wpid = File.read(path).to_i
wpid <= 0 and return
Process.kill(0, wpid)
wpid
rescue Errno::EPERM
@logger.info "pid=#{path} possibly stale, got EPERM signalling PID:#{wpid}"
nil
rescue Errno::ESRCH, Errno::ENOENT
# don't unlink stale pid files, racy without non-portable locking...
end
def load_config!
@logger.info "reloading config_file=#{@config.config_file}"
@config.config_reload!
@config.commit!(self)
soft_kill_each_worker("QUIT")
Yahns::Log.reopen_all
@logger.info "done reloading config_file=#{@config.config_file}"
rescue StandardError, LoadError, SyntaxError => e
Yahns::Log.exception(@logger,
"error reloading config_file=#{@config.config_file}", e)
end
# returns an array of string names for the given listener array
def listener_names(listeners = @listeners)
listeners.map { |io| sock_name(io) }
end
def sock_opts(io)
@config.config_listeners[sock_name(io)] || {}
end
def inherit_listeners!
# inherit sockets from parents, they need to be plain Socket objects
# before they become Yahns::UNIXServer or Yahns::TCPServer
#
# Note: we intentionally use a yahns-specific environment variable
# here because existing servers may use non-blocking listen sockets.
# yahns uses _blocking_ listen sockets exclusively. We cannot
# change an existing socket to blocking mode if two servers are
# running (one expecting blocking, one expecting non-blocking)
# because that can completely break the non-blocking one.
# Unfortunately, there is no one-off MSG_DONTWAIT-like flag for
# accept4(2).
inherited = ENV['YAHNS_FD'].to_s.split(',')
# emulate sd_listen_fds() for systemd
sd_pid, sd_fds = ENV.values_at('LISTEN_PID', 'LISTEN_FDS')
if sd_pid.to_i == $$
# 3 = SD_LISTEN_FDS_START
inherited.concat((3...(3 + sd_fds.to_i)).to_a)
end
# to ease debugging, we will not unset LISTEN_PID and LISTEN_FDS
inherited.map! do |fd|
io = Socket.for_fd(fd.to_i)
opts = sock_opts(io)
io = server_cast(io, opts)
set_server_sockopt(io, opts)
name = sock_name(io)
@logger.info "inherited addr=#{name} fd=#{io.fileno}"
@config.register_inherited(name)
io
end
@listeners.replace(inherited)
end
# call only after calling inherit_listeners!
# This binds any listeners we did NOT inherit from the parent
def bind_new_listeners!
self.listeners = @config.config_listeners.keys
raise ArgumentError, "no listeners" if @listeners.empty?
end
def proc_name(tag)
s = Yahns::START
$0 = ([ File.basename(s[0]), tag ]).concat(s[:argv]).join(' ')
end
def qegg_vivify(qegg, fdmap)
queue = qegg.vivify(fdmap)
qegg.worker_threads.times do
@wthr << queue.worker_thread(@logger, qegg.max_events)
end
@queues << queue
queue
end
# spins up processing threads of the server
def fdmap_init
thresh = @config.value(:client_expire_threshold)
# keeps track of all connections, like ObjectSpace, but only for IOs
fdmap = Yahns::Fdmap.new(@logger, thresh)
# once initialize queues (epoll/kqueue) and associated worker threads
queues = {}
# spin up applications (which are preload: false)
@config.app_ctx.each(&:after_fork_init)
@shutdown_timeout ||= @config.app_ctx.map(&:client_timeout).max
# spin up acceptor threads, clients flow into worker queues after this
@listeners.each do |l|
opts = sock_opts(l)
ctx = opts[:yahns_app_ctx]
ctx_list = opts[:yahns_app_ctx_list] ||= []
qegg = ctx.qegg || @config.qeggs[:default]
ctx.queue = queues[qegg] ||= qegg_vivify(qegg, fdmap)
ctx = ctx.dup
ctx.__send__(:include, l.expire_mod)
if ssl_ctx = opts[:ssl_ctx]
ctx.__send__(:include, Yahns::OpenSSLClient)
env = ctx.app_defaults = ctx.app_defaults.dup
env['HTTPS'] = 'on' # undocumented, but Rack::Request uses this
env['rack.url_scheme'] = 'https'
# avoid "session id context uninitialized" errors when a client
# attempts to reuse a cached SSL session. Server admins may
# configure their own cache and session_id_context if desired.
# 32 bytes is SSL_MAX_SSL_SESSION_ID_LENGTH and has been since
# the SSLeay days
ssl_ctx.session_id_context ||= OpenSSL::Random.random_bytes(32)
# call OpenSSL::SSL::SSLContext#setup explicitly here to detect
# errors and avoid race conditions. We avoid calling this in the
# parent process since
ssl_ctx.setup
end
ctx_list << ctx
# acceptors feed the the queues
l.spawn_acceptor(opts[:threads] || 1, @logger, ctx)
end
fdmap
end
def usr1_reopen(prefix)
@logger.info "#{prefix}reopening logs..."
Yahns::Log.reopen_all
@logger.info "#{prefix}done reopening logs"
end
def quit_enter(alive)
if alive
@logger.info("gracefully exiting shutdown_timeout=#@shutdown_timeout")
@shutdown_expire ||= Yahns.now + @shutdown_timeout + 1
else # drop connections immediately if signaled twice
@logger.info("graceful exit aborted, exiting immediately")
# we will still call any app-defined at_exit hooks here
# use SIGKILL if you don't want that.
exit
end
drop_acceptors # stop acceptors, we close epolls in quit_done
@config.config_listeners.each_value do |opts|
list= opts[:yahns_app_ctx_list] or next
# Yahns::HttpContext#persistent_connections=
list.each { |ctx| ctx.persistent_connections = false }
end
false
end
# drops all the the IO objects we have threads waiting on before exiting
# This just injects the QueueQuitter object which acts like a
# monkey wrench thrown into a perfectly good engine :)
def quit_finish
quitter = Yahns::QueueQuitter.new
# throw the monkey wrench into the worker threads
@queues.each { |q| q.queue_add(quitter, Yahns::Queue::QEV_QUIT) }
# watch the monkey wrench destroy all the threads!
# Ugh, this may fail if we have dedicated threads trickling
# response bodies out (e.g. "tail -F") Oh well, have a timeout
begin
@wthr.delete_if { |t| t.join(0.01) }
end while @wthr[0] && Yahns.now <= @shutdown_expire
# cleanup, our job is done
@queues.each(&:close).clear
# we must not let quitter get GC-ed if we have any worker threads leftover
@quitter = quitter
quitter.close
rescue => e
Yahns::Log.exception(@logger, "quit finish", e)
ensure
if (@wthr.size + @listeners.size) > 0
@logger.warn("still active wthr=#{@wthr.size} "\
"listeners=#{@listeners.size}")
end
end
def reap_reexec
@reexec_pid > 0 or return
wpid, status = Process.waitpid2(@reexec_pid, Process::WNOHANG)
wpid or return
@logger.error "reaped #{status.inspect} exec()-ed"
@reexec_pid = 0
self.pid = @pid.chomp('.oldbin') if @pid
end
def sp_sig_handle(alive)
@sev.kgio_wait_readable(alive ? nil : 0.01)
@sev.yahns_step
case sig = @sig_queue.shift
when :QUIT, :TERM, :INT
return quit_enter(alive)
when :CHLD
reap_reexec
when :USR1
usr1_reopen(nil)
when :USR2
reexec
when :HUP
reexec
return quit_enter(alive)
when :TTIN, :TTOU, :WINCH
@logger.info("SIG#{sig} ignored in single-process mode")
end
alive
end
def dropping(fdmap)
if drop_acceptors[0] || fdmap.size > 0
timeout = @shutdown_expire < Yahns.now ? -1 : @shutdown_timeout
n = fdmap.desperate_expire(timeout)
$0 = "yahns quitting, #{n} FD(s) remain"
true
else
false
end
end
# single-threaded only, this is overriden if @worker_processes is non-nil
def join
daemon_ready
fdmap = fdmap_init
alive = true
begin
alive = sp_sig_handle(alive)
rescue => e
Yahns::Log.exception(@logger, "main loop", e)
end while alive || dropping(fdmap)
unlink_pid_safe(@pid) if @pid
ensure
quit_finish
end
end
|