about summary refs log tree commit
diff options
context:
space:
mode:
authorEric Wong <e@yhbt.net>2020-03-21 02:03:50 +0000
committerEric Wong <e@yhbt.net>2020-03-25 01:48:35 +0000
commitd111c17ff06c9af7e0690e4b00a0eeb1c505c92a (patch)
treea79425d1a90e4d940a40742ef90523bbb380f00e
parent90dc2b8ca53f93ca937e7cc71cd7c915e3df8020 (diff)
downloadpublic-inbox-d111c17ff06c9af7e0690e4b00a0eeb1c505c92a.tar.gz
As sqlite3(1) and other executables may become unavailable or
uninstalled while a daemon runs, we need to gracefully handle
errors in those cases.
-rw-r--r--lib/PublicInbox/Qspawn.pm58
-rw-r--r--t/httpd-corner.psgi7
-rw-r--r--t/httpd-corner.t25
3 files changed, 64 insertions, 26 deletions
diff --git a/lib/PublicInbox/Qspawn.pm b/lib/PublicInbox/Qspawn.pm
index 52aea3eb..34b6912f 100644
--- a/lib/PublicInbox/Qspawn.pm
+++ b/lib/PublicInbox/Qspawn.pm
@@ -45,7 +45,7 @@ sub new ($$$;) {
 sub _do_spawn {
         my ($self, $start_cb, $limiter) = @_;
         my $err;
-        my ($cmd, $cmd_env, $opt) = @{$self->{args}};
+        my ($cmd, $cmd_env, $opt) = @{delete $self->{args}};
         my %o = %{$opt || {}};
         $self->{limiter} = $limiter;
         foreach my $k (PublicInbox::Spawn::RLIMITS()) {
@@ -53,20 +53,17 @@ sub _do_spawn {
                         $o{$k} = $rlimit;
                 }
         }
+        $self->{cmd} = $o{quiet} ? undef : $cmd;
         eval {
                 # popen_rd may die on EMFILE, ENFILE
                 ($self->{rpipe}, $self->{pid}) = popen_rd($cmd, $cmd_env, \%o);
-                $self->{args} = $o{quiet} ? undef : $cmd;
 
                 die "E: $!" unless defined($self->{pid});
 
                 $limiter->{running}++;
                 $start_cb->($self); # EPOLL_CTL_ADD may ENOSPC/ENOMEM
         };
-        if ($@) {
-                $self->{err} = $@;
-                finish($self);
-        }
+        finish($self, $@) if $@;
 }
 
 sub child_err ($) {
@@ -83,16 +80,8 @@ sub log_err ($$) {
         $env->{'psgi.errors'}->print($msg, "\n");
 }
 
-# callback for dwaitpid
-sub waitpid_err ($$) {
-        my ($self, $pid) = @_;
-        my $xpid = delete $self->{pid};
-        my $err;
-        if ($pid > 0) { # success!
-                $err = child_err($?);
-        } elsif ($pid < 0) { # ??? does this happen in our case?
-                $err = "W: waitpid($xpid, 0) => $pid: $!";
-        } # else should not be called with pid == 0
+sub finalize ($$) {
+        my ($self, $err) = @_;
 
         my ($env, $qx_cb, $qx_arg, $qx_buf) =
                 delete @$self{qw(psgi_env qx_cb qx_arg qx_buf)};
@@ -108,16 +97,37 @@ sub waitpid_err ($$) {
         }
 
         if ($err) {
-                if ($self->{err}) {
+                if (defined $self->{err}) {
                         $self->{err} .= "; $err";
                 } else {
                         $self->{err} = $err;
                 }
-                if ($env && $self->{args}) {
-                        log_err($env, join(' ', @{$self->{args}}) . ": $err");
+                if ($env && $self->{cmd}) {
+                        log_err($env, join(' ', @{$self->{cmd}}) . ": $err");
                 }
         }
-        eval { $qx_cb->($qx_buf, $qx_arg) } if $qx_cb;
+        if ($qx_cb) {
+                eval { $qx_cb->($qx_buf, $qx_arg) };
+        } elsif (my $wcb = delete $env->{'qspawn.wcb'}) {
+                # have we started writing, yet?
+                require PublicInbox::WwwStatic;
+                $wcb->(PublicInbox::WwwStatic::r(500));
+        }
+}
+
+# callback for dwaitpid
+sub waitpid_err ($$) {
+        my ($self, $pid) = @_;
+        my $xpid = delete $self->{pid};
+        my $err;
+        if (defined $pid) {
+                if ($pid > 0) { # success!
+                        $err = child_err($?);
+                } elsif ($pid < 0) { # ??? does this happen in our case?
+                        $err = "W: waitpid($xpid, 0) => $pid: $!";
+                } # else should not be called with pid == 0
+        }
+        finalize($self, $err);
 }
 
 sub do_waitpid ($) {
@@ -133,14 +143,12 @@ sub do_waitpid ($) {
         }
 }
 
-sub finish ($) {
-        my ($self) = @_;
+sub finish ($;$) {
+        my ($self, $err) = @_;
         if (delete $self->{rpipe}) {
                 do_waitpid($self);
         } else {
-                my ($env, $qx_cb, $qx_arg, $qx_buf) =
-                        delete @$self{qw(psgi_env qx_cb qx_arg qx_buf)};
-                eval { $qx_cb->($qx_buf, $qx_arg) } if $qx_cb;
+                finalize($self, $err);
         }
 }
 
diff --git a/t/httpd-corner.psgi b/t/httpd-corner.psgi
index f2427234..44629620 100644
--- a/t/httpd-corner.psgi
+++ b/t/httpd-corner.psgi
@@ -94,6 +94,13 @@ my $app = sub {
                 return $qsp->psgi_return($env, undef, sub {
                         [ 200, [ qw(Content-Type application/octet-stream)]]
                 });
+        } elsif ($path eq '/psgi-return-enoent') {
+                require PublicInbox::Qspawn;
+                my $cmd = [ 'this-better-not-exist-in-PATH'.rand ];
+                my $qsp = PublicInbox::Qspawn->new($cmd);
+                return $qsp->psgi_return($env, undef, sub {
+                        [ 200, [ qw(Content-Type application/octet-stream)]]
+                });
         } elsif ($path eq '/pid') {
                 $code = 200;
                 push @$body, "$$\n";
diff --git a/t/httpd-corner.t b/t/httpd-corner.t
index e50aa436..cbfc8332 100644
--- a/t/httpd-corner.t
+++ b/t/httpd-corner.t
@@ -10,6 +10,7 @@ use PublicInbox::Spawn qw(which spawn);
 use PublicInbox::TestCommon;
 require_mods(qw(Plack::Util Plack::Builder HTTP::Date HTTP::Status));
 use Digest::SHA qw(sha1_hex);
+use IO::Handle ();
 use IO::Socket;
 use IO::Socket::UNIX;
 use Fcntl qw(:seek);
@@ -336,6 +337,14 @@ SKIP: {
 }
 
 {
+        my $conn = conn_for($sock, 'psgi_return ENOENT');
+        print $conn "GET /psgi-return-enoent HTTP/1.1\r\n\r\n" or die;
+        my $buf = '';
+        sysread($conn, $buf, 16384, length($buf)) until $buf =~ /\r\n\r\n/;
+        like($buf, qr!HTTP/1\.[01] 500\b!, 'got 500 error on ENOENT');
+}
+
+{
         my $conn = conn_for($sock, '1.1 pipeline together');
         $conn->write("PUT /sha1 HTTP/1.1\r\nUser-agent: hello\r\n\r\n" .
                         "PUT /sha1 HTTP/1.1\r\n\r\n");
@@ -610,6 +619,11 @@ SKIP: {
         require_mods(@zmods, qw(Plack::Test HTTP::Request::Common), 3);
         use_ok 'HTTP::Request::Common';
         use_ok 'Plack::Test';
+        STDERR->flush;
+        open my $olderr, '>&', \*STDERR or die "dup stderr: $!";
+        open my $tmperr, '+>', undef or die;
+        open STDERR, '>&', $tmperr or die;
+        STDERR->autoflush(1);
         my $app = require $psgi;
         test_psgi($app, sub {
                 my ($cb) = @_;
@@ -617,8 +631,17 @@ SKIP: {
                 my $res = $cb->($req);
                 my $buf = $res->content;
                 IO::Uncompress::Gunzip::gunzip(\$buf => \(my $out));
-                is($out, "hello world\n");
+                is($out, "hello world\n", 'got expected output');
+
+                $req = GET('http://example.com/psgi-return-enoent');
+                $res = $cb->($req);
+                is($res->code, 500, 'got error on ENOENT');
+                seek($tmperr, 0, SEEK_SET) or die;
+                my $errbuf = do { local $/; <$tmperr> };
+                like($errbuf, qr/this-better-not-exist/,
+                        'error logged about missing command');
         });
+        open STDERR, '>&', $olderr or die "restore stderr: $!";
 }
 
 done_testing();