From 5dfd4af2452a2fdb28e046e15a44b2d13bdacac0 Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Sat, 19 Sep 2015 08:42:58 +0000 Subject: nntpd: support systemd FD inheritance + signals Avoid depending on IO::Socket::INET if we can help it, we do not need to bloat ourselves with lot of that functionality. --- public-inbox-nntpd | 301 +++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 280 insertions(+), 21 deletions(-) (limited to 'public-inbox-nntpd') diff --git a/public-inbox-nntpd b/public-inbox-nntpd index 0c221fa3..588efdd3 100644 --- a/public-inbox-nntpd +++ b/public-inbox-nntpd @@ -3,38 +3,297 @@ # License: AGPLv3 or later (https://www.gnu.org/licenses/agpl-3.0.txt) use strict; use warnings; +my @CMD = ($0, @ARGV); require Danga::Socket; -use IO::Socket; -use Socket qw(SO_KEEPALIVE IPPROTO_TCP TCP_NODELAY); -require PublicInbox::NNTP; +require IO::Handle; +use Getopt::Long qw/:config gnu_getopt no_ignore_case auto_abbrev/; require PublicInbox::NewsGroup; my $nntpd = PublicInbox::NNTPD->new; my $refresh = sub { $nntpd->refresh_groups }; +$SIG{HUP} = $SIG{USR1} = $SIG{USR2} = $SIG{PIPE} = + $SIG{TTIN} = $SIG{TTOU} = $SIG{WINCH} = 'IGNORE'; +$refresh->(); +my (@cfg_listen, $stdout, $stderr); +my $worker_processes = 0; my %opts = ( - LocalAddr => '127.0.0.1:1133', - Type => SOCK_STREAM, - Proto => 'tcp', - Blocking => 0, - Reuse => 1, - Listen => 1024, + 'l|listen=s' => \@cfg_listen, + '1|stdout=s' => \$stdout, + '2|stderr=s' => \$stderr, + 'W|worker-processes=i' => \$worker_processes, ); -my $s = IO::Socket::INET->new(%opts) or die "Error creating socket: $@\n"; -$s->sockopt(SO_KEEPALIVE, 1); -$s->setsockopt(IPPROTO_TCP, TCP_NODELAY, 1); +GetOptions(%opts) or die "bad command-line args\n"; +my %pids; +my %listener_names; +my $reexec_pid; +my @listeners = inherit(); -$SIG{PIPE} = 'IGNORE'; -$SIG{HUP} = $refresh; -$refresh->(); +# default NNTP listener if no listeners +push @cfg_listen, '0.0.0.0:119' unless (@listeners || @cfg_listen); + +foreach my $l (@cfg_listen) { + next if $listener_names{$l}; # already inherited + require IO::Socket::INET6; # works for IPv4, too + my %o = ( + LocalAddr => $l, + ReuseAddr => 1, + Proto => 'tcp', + ); + if (my $s = IO::Socket::INET6->new(%o)) { + $listener_names{sockname($s)} = $s; + push @listeners, $s; + } else { + warn "error binding $l: $!\n"; + } +} +die 'No listeners bound' unless @listeners; +open(STDIN, '+<', '/dev/null'); + +if ($worker_processes > 0) { + # my ($p0, $p1, $r, $w); + pipe(my ($p0, $p1)) or die "failed to create parent-pipe: $!\n"; + my %pwatch = ( fileno($p0) => sub { kill('TERM', $$) } ); + pipe(my ($r, $w)) or die "failed to create self-pipe: $!\n"; + IO::Handle::blocking($w, 0); + my $set_workers = $worker_processes; + my @caught; + my $master_pid = $$; + foreach my $s (qw(HUP CHLD QUIT INT TERM USR1 USR2 TTIN TTOU WINCH)) { + $SIG{$s} = sub { + return if $$ != $master_pid; + push @caught, $s; + syswrite($w, '.'); + }; + } + reopen_logs(); + # main loop + while (1) { + while (my $s = shift @caught) { + if ($s eq 'USR1') { + reopen_logs(); + kill_workers($s); + } elsif ($s eq 'USR2') { + upgrade(); + } elsif ($s =~ /\A(?:QUIT|TERM|INT)\z/) { + # drops pipes and causes children to die + exit + } elsif ($s eq 'WINCH') { + $worker_processes = 0; + } elsif ($s eq 'HUP') { + $worker_processes = $set_workers; + $refresh->(); + kill_workers($s); + } elsif ($s eq 'TTIN') { + if ($set_workers > $worker_processes) { + ++$worker_processes; + } else { + $worker_processes = ++$set_workers; + } + } elsif ($s eq 'TTOU') { + if ($set_workers > 0) { + $worker_processes = --$set_workers; + } + } elsif ($s eq 'CHLD') { + reap_children(); + } + } + + my $n = scalar keys %pids; + if ($n > $worker_processes) { + while (my ($k, $v) = each %pids) { + kill('TERM', $k) if $v >= $worker_processes; + } + $n = $worker_processes; + } + foreach my $i ($n..($worker_processes - 1)) { + my ($pid, $err) = do_fork(); + if (!defined $pid) { + warn "failed to fork worker[$i]: $err\n"; + } elsif ($pid == 0) { + close($_) for ($w, $r, $p1); + Danga::Socket->AddOtherFds(%pwatch); + goto worker; + } else { + warn "PID=$pid is worker[$i]\n"; + $pids{$pid} = $i; + } + } + sysread($r, my $buf, 8); + } +} else { +worker: + # this calls epoll_create: + @listeners = map { PublicInbox::Listener->new($_) } @listeners; + reopen_logs(); + $SIG{QUIT} = $SIG{INT} = $SIG{TERM} = *worker_quit; + $SIG{USR1} = *reopen_logs; + $SIG{HUP} = $refresh; + $_->watch_read(1) for @listeners; + Danga::Socket->EventLoop; +} + +# end of main + +sub worker_quit { + # killing again terminates immediately: + exit unless @listeners; -Danga::Socket->AddOtherFds(fileno($s) => sub { - while (my $c = $s->accept) { - $c->blocking(0); # no accept4 :< + $_->close for @listeners; + @listeners = (); + + # drop idle connections and try to quit gracefully + Danga::Socket->SetPostLoopCallback(sub { + my ($dmap, undef) = @_; + my $n = 0; + foreach my $s (values %$dmap) { + if ($s->{write_buf_size} || @{$s->{read_push_back}}) { + ++$n; + } else { + $s->close; + } + } + $n; # true: loop continues, false: loop breaks + }); +} + +sub reopen_logs { + if ($stdout) { + open STDOUT, '>>', $stdout or + warn "failed to redirect stdout to $stdout: $!\n"; + } + if ($stderr) { + open STDERR, '>>', $stderr or + warn "failed to redirect stderr to $stderr: $!\n"; + } +} + +sub sockname { + my ($s) = @_; + my $n = getsockname($s) or return; + my ($port, $addr); + if (bytes::length($n) >= 28) { + require Socket6; + ($port, $addr) = Socket6::unpack_sockaddr_in6($n); + } else { + ($port, $addr) = Socket::sockaddr_in($n); + } + if (bytes::length($addr) == 4) { + $n = Socket::inet_ntoa($addr) + } else { + $n = '['.Socket6::inet_ntop(Socket6::AF_INET6(), $addr).']'; + } + $n .= ":$port"; +} + +sub inherit { + return () if ($ENV{LISTEN_PID} || 0) != $$; + my $fds = $ENV{LISTEN_FDS} or return (); + my $end = $fds + 2; # LISTEN_FDS_START - 1 + my @rv = (); + foreach my $fd (3..$end) { + my $s = IO::Handle->new; + $s->fdopen($fd, 'r'); + if (my $k = sockname($s)) { + $listener_names{$k} = $s; + push @rv, $s; + } else { + warn "failed to inherit fd=$fd (LISTEN_FDS=$fds)"; + } + } + @rv +} + +sub upgrade { + if ($reexec_pid) { + warn "upgrade in-progress: $reexec_pid\n"; + return; + } + my ($pid, $err) = do_fork(); + unless (defined $pid) { + warn "fork failed: $err\n"; + return; + } + if ($pid == 0) { + use Fcntl qw(FD_CLOEXEC F_SETFD F_GETFD); + $ENV{LISTEN_FDS} = scalar @listeners; + $ENV{LISTEN_PID} = $$; + foreach my $s (@listeners) { + my $fl = fcntl($s, F_GETFD, 0); + fcntl($s, F_SETFD, $fl &= ~FD_CLOEXEC); + } + exec @CMD; + die "Failed to exec: $!\n"; + } + $reexec_pid = $pid; +} + +sub kill_workers { + my ($s) = @_; + + while (my ($pid, $id) = each %pids) { + kill $s, $pid; + } +} + +sub do_fork { + require POSIX; + my $new = POSIX::SigSet->new; + $new->fillset; + my $old = POSIX::SigSet->new; + POSIX::sigprocmask(&POSIX::SIG_BLOCK, $new, $old) or + die "SIG_BLOCK: $!\n"; + my $pid = fork; + my $err = $!; + POSIX::sigprocmask(&POSIX::SIG_SETMASK, $old) or + die "SIG_SETMASK: $!\n"; + ($pid, $err); +} + +sub reap_children { + while (1) { + my $p = waitpid(-1, &POSIX::WNOHANG) or return; + if (defined $reexec_pid && $p == $reexec_pid) { + $reexec_pid = undef; + warn "reexec PID($p) died with: $?\n"; + } elsif (defined(my $id = delete $pids{$p})) { + warn "worker[$id] PID($p) died with: $?\n"; + } elsif ($p > 0) { + warn "unknown PID($p) reaped: $?\n"; + } else { + return; + } + } +} + +1; +package PublicInbox::Listener; +use strict; +use warnings; +use base 'Danga::Socket'; +use Socket qw(SOL_SOCKET SO_KEEPALIVE IPPROTO_TCP TCP_NODELAY); +use PublicInbox::NNTP; + +sub new ($$) { + my ($class, $s) = @_; + setsockopt($s, SOL_SOCKET, SO_KEEPALIVE, 1); + setsockopt($s, IPPROTO_TCP, TCP_NODELAY, 1); + listen($s, 1024); + IO::Handle::blocking($s, 0); + my $self = fields::new($class); + $self->SUPER::new($s); +} + +sub event_read { + my ($self) = @_; + # no loop here, we want to fairly distribute clients + # between multiple processes sharing the same socket + if (accept(my $c, $self->{sock})) { + IO::Handle::blocking($c, 0); # no accept4 :< PublicInbox::NNTP->new($c, $nntpd); } -}); -Danga::Socket->EventLoop(); +} +1; package PublicInbox::NNTPD; use strict; use warnings; @@ -70,7 +329,7 @@ sub refresh_groups { } # Only valid if Msgmap works - $new->{$g} = $ng if $ng->mm; + $new->{$g} = $ng if $ng->mm(1); } # this will destroy old groups that got deleted %{$self->{groups}} = %$new; -- cgit v1.2.3-24-ge0c7