http: support graceful shutdown like nntp

HTTP responses may be long-running or requests may be slow or
pipelined.  Ensure we don't kill them off prematurely.

diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index f1016d2f0e139cb8460448c1d02102d0ee0ed9b9..928c0f22469ca8bd73b74646b3d40d789ad587bf 100644 (file)
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -103,7 +103,6 @@ sub app_dispatch ($) {
        my ($self) = @_;
        $self->watch_read(0);
        my $env = $self->{env};
-       $self->{env} = undef;
        $env->{REMOTE_ADDR} = $self->peer_ip_string; # Danga::Socket
        $env->{REMOTE_PORT} = $self->{peer_port}; # set by peer_ip_string
        if (my $host = $env->{HTTP_HOST}) {
@@ -169,6 +168,7 @@ sub response_write {
                } else {
                        $self->write(sub { $self->close });
                }
+               $self->{env} = undef;
        };
 
        if (defined $res->[2]) {
@@ -336,4 +336,10 @@ sub quit {
 sub event_hup { $_[0]->close }
 sub event_err { $_[0]->close }
 
+# for graceful shutdown in PublicInbox::Daemon:
+sub busy () {
+       my ($self) = @_;
+       ($self->{rbuf} ne '' || $self->{env} || $self->{write_buf_size});
+}
+
 1;

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 097c57e9b23b8573328b477ac0752ca58b76c9b3..bcce77038dd124990459c38f235702151138a31f 100644 (file)
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -954,6 +954,7 @@ sub watch_read {
        $rv;
 }
 
+# for graceful shutdown in PublicInbox::Daemon:
 sub busy () {
        my ($self) = @_;
        ($self->{rbuf} ne '' || $self->{long_res} || $self->{write_buf_size});

diff --git a/t/httpd-corner.psgi b/t/httpd-corner.psgi
index 1947f37600a3928ebb37f4aaf40dfc0be3d3207d..0e0e21a84cd585cf187793c8f85f85b78f574d10 100644 (file)
--- a/t/httpd-corner.psgi
+++ b/t/httpd-corner.psgi
@@ -26,7 +26,27 @@ my $app = sub {
                }
                $code = 200;
                push @$body, $sha1->hexdigest;
+       } elsif (my $fifo = $env->{HTTP_X_CHECK_FIFO}) {
+               if ($path eq '/slow-header') {
+                       return sub {
+                               open my $f, '<', $fifo or
+                                               die "open $fifo: $!\n";
+                               my @r = <$f>;
+                               $_[0]->([200, $h, \@r ]);
+                       };
+               } elsif ($path eq '/slow-body') {
+                       return sub {
+                               my $fh = $_[0]->([200, $h]);
+                               open my $f, '<', $fifo or
+                                               die "open $fifo: $!\n";
+                               while (defined(my $l = <$f>)) {
+                                       $fh->write($l);
+                               }
+                               $fh->close;
+                       };
+               }
        }
+
        [ $code, $h, $body ]
 };
 

diff --git a/t/httpd-corner.t b/t/httpd-corner.t
index 366e56cb5d3f04b2f00b5e9ee3e6ae983a6d55f0..40692086ad7cb8218e6d9d735f85843e76e89f67 100644 (file)
--- a/t/httpd-corner.t
+++ b/t/httpd-corner.t
@@ -18,7 +18,10 @@ use Cwd qw/getcwd/;
 use IO::Socket;
 use Fcntl qw(FD_CLOEXEC F_SETFD F_GETFD :seek);
 use Socket qw(SO_KEEPALIVE IPPROTO_TCP TCP_NODELAY);
+use POSIX qw(dup2 mkfifo :sys_wait_h);
 my $tmpdir = tempdir(CLEANUP => 1);
+my $fifo = "$tmpdir/fifo";
+ok(defined mkfifo($fifo, 0777), 'created FIFO');
 my $err = "$tmpdir/stderr.log";
 my $out = "$tmpdir/stdout.log";
 my $httpd = 'blib/script/public-inbox-httpd';
@@ -33,27 +36,31 @@ my %opts = (
 my $sock = IO::Socket::INET->new(%opts);
 my $pid;
 END { kill 'TERM', $pid if defined $pid };
-{
-       ok($sock, 'sock created');
-       $! = 0;
+my $spawn_httpd = sub {
+       my (@args) = @_;
        my $fl = fcntl($sock, F_GETFD, 0);
        ok(! $!, 'no error from fcntl(F_GETFD)');
        is($fl, FD_CLOEXEC, 'cloexec set by default (Perl behavior)');
        $pid = fork;
        if ($pid == 0) {
-               use POSIX qw(dup2);
                # pretend to be systemd
                fcntl($sock, F_SETFD, $fl &= ~FD_CLOEXEC);
                dup2(fileno($sock), 3) or die "dup2 failed: $!\n";
                $ENV{LISTEN_PID} = $$;
                $ENV{LISTEN_FDS} = 1;
-               exec $httpd, '-W0', "--stdout=$out", "--stderr=$err", $psgi;
+               exec $httpd, @args, "--stdout=$out", "--stderr=$err", $psgi;
                die "FAIL: $!\n";
        }
        ok(defined $pid, 'forked httpd process successfully');
+};
+
+{
+       ok($sock, 'sock created');
        $! = 0;
-       fcntl($sock, F_SETFD, $fl |= FD_CLOEXEC);
-       ok(! $!, 'no error from fcntl(F_SETFD)');
+       my $fl = fcntl($sock, F_GETFD, 0);
+       ok(! $!, 'no error from fcntl(F_GETFD)');
+       is($fl, FD_CLOEXEC, 'cloexec set by default (Perl behavior)');
+       $spawn_httpd->('-W0');
 }
 
 sub conn_for {
@@ -69,6 +76,58 @@ sub conn_for {
        return $conn;
 }
 
+# graceful termination
+{
+       my $conn = conn_for($sock, 'graceful termination via slow header');
+       $conn->write("GET /slow-header HTTP/1.0\r\n" .
+                       "X-Check-Fifo: $fifo\r\n\r\n");
+       open my $f, '>', $fifo or die "open $fifo: $!\n";
+       $f->autoflush(1);
+       ok(print($f "hello\n"), 'wrote something to fifo');
+       my $kpid = $pid;
+       $pid = undef;
+       is(kill('TERM', $kpid), 1, 'started graceful shutdown');
+       ok(print($f "world\n"), 'wrote else to fifo');
+       close $f or die "close fifo: $!\n";
+       $conn->read(my $buf, 8192);
+       my ($head, $body) = split(/\r\n\r\n/, $buf, 2);
+       like($head, qr!\AHTTP/1\.[01] 200 OK!, 'got 200 for slow-header');
+       is($body, "hello\nworld\n", 'read expected body');
+       is(waitpid($kpid, 0), $kpid, 'reaped httpd');
+       is($?, 0, 'no error');
+       $spawn_httpd->('-W0');
+}
+
+{
+       my $conn = conn_for($sock, 'graceful termination via slow-body');
+       $conn->write("GET /slow-body HTTP/1.0\r\n" .
+                       "X-Check-Fifo: $fifo\r\n\r\n");
+       open my $f, '>', $fifo or die "open $fifo: $!\n";
+       $f->autoflush(1);
+       my $buf;
+       $conn->sysread($buf, 8192);
+       like($buf, qr!\AHTTP/1\.[01] 200 OK!, 'got 200 for slow-body');
+       like($buf, qr!\r\n\r\n!, 'finished HTTP response header');
+
+       foreach my $c ('a'..'c') {
+               $c .= "\n";
+               ok(print($f $c), 'wrote line to fifo');
+               $conn->sysread($buf, 8192);
+               is($buf, $c, 'got trickle for reading');
+       }
+       my $kpid = $pid;
+       $pid = undef;
+       is(kill('TERM', $kpid), 1, 'started graceful shutdown');
+       ok(print($f "world\n"), 'wrote else to fifo');
+       close $f or die "close fifo: $!\n";
+       $conn->sysread($buf, 8192);
+       is($buf, "world\n", 'read expected body');
+       is($conn->sysread($buf, 8192), 0, 'got EOF from server');
+       is(waitpid($kpid, 0), $kpid, 'reaped httpd');
+       is($?, 0, 'no error');
+       $spawn_httpd->('-W0');
+}
+
 sub delay { select(undef, undef, undef, shift || rand(0.02)) }
 
 my $str = 'abcdefghijklmnopqrstuvwxyz';
@@ -140,6 +199,28 @@ SKIP: {
        }
 }
 
+{
+       my $conn = conn_for($sock, 'graceful termination during slow request');
+       $conn->write("PUT /sha1 HTTP/1.0\r\n");
+       delay();
+       $conn->write("Content-Length: $len\r\n");
+       delay();
+       $conn->write("\r\n");
+       my $kpid = $pid;
+       $pid = undef;
+       is(kill('TERM', $kpid), 1, 'started graceful shutdown');
+       delay();
+       my $n = 0;
+       foreach my $c ('a'..'z') {
+               $n += $conn->write($c);
+       }
+       is($n, $len, 'wrote alphabet');
+       $check_self->($conn);
+       is(waitpid($kpid, 0), $kpid, 'reaped httpd');
+       is($?, 0, 'no error');
+       $spawn_httpd->('-W0');
+}
+
 # various DoS attacks against the chunk parser:
 {
        local $SIG{PIPE} = 'IGNORE';