lei: dump errors to syslog, and not to CLI

Dumping errors from the previous run can often get lost, so just
spew to syslog since it's a standard place to put errors that
don't make it to a client.  Note: we don't rely on $SIG{__WARN__}
since some of the Net:: stuff will write directly to STDERR
(as will external processes).

3 files changed, 11 insertions, 14 deletions

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index 41e811ca..9e9aa165 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -27,6 +27,7 @@ use PublicInbox::Eml;
 use Time::HiRes qw(stat); # ctime comparisons for config cache
 use File::Path qw(mkpath);
 use File::Spec;
+use Sys::Syslog qw(openlog syslog closelog);
 our $quit = \&CORE::exit;
 our ($current_lei, $errors_log, $listener, $oldset, $dir_idle,
         $recv_cmd, $send_cmd);
@@ -464,7 +465,6 @@ sub x_it ($$) {
         my ($self, $code) = @_;
         # make sure client sees stdout before exit
         $self->{1}->autoflush(1) if $self->{1};
-        dump_and_clear_log();
         stop_pager($self);
         if ($self->{pkt_op_p}) { # to top lei-daemon
                 $self->{pkt_op_p}->pkt_do('x_it', $code);
@@ -765,7 +765,6 @@ sub dispatch {
         my ($self, $cmd, @argv) = @_;
         local $current_lei = $self; # for __WARN__
         $self->{2}->autoflush(1); # keep stdout buffered until x_it|DESTROY
-        dump_and_clear_log("from previous run\n");
         return _help($self, 'no command given') unless defined($cmd);
         # do not support Getopt bundling for this
         while ($cmd eq '-C' || $cmd eq '-c') {
@@ -1147,10 +1146,12 @@ sub oldset { $oldset }
 
 sub dump_and_clear_log {
         if (defined($errors_log) && -s STDIN && seek(STDIN, 0, SEEK_SET)) {
-                my @pfx = @_;
-                unshift(@pfx, "$errors_log ") if @pfx;
-                warn @pfx, do { local $/; <STDIN> };
-                truncate(STDIN, 0) or warn "ftruncate ($errors_log): $!";
+                openlog('lei-daemon', 'pid,nowait,nofatal,ndelay', 'user');
+                chomp(my @lines = <STDIN>);
+                truncate(STDIN, 0) or
+                        syslog('warning', "ftruncate (%s): %m", $errors_log);
+                for my $l (@lines) { syslog('warning', '%s', $l) }
+                closelog(); # don't share across fork
         }
 }
 
@@ -1243,7 +1244,7 @@ sub lazy_start {
         (-p STDOUT) or die "E: stdout must be a pipe\n";
         open(STDIN, '+>>', $errors_log) or die "open($errors_log): $!";
         STDIN->autoflush(1);
-        dump_and_clear_log("from previous daemon process:\n");
+        dump_and_clear_log();
         POSIX::setsid() > 0 or die "setsid: $!";
         my $pid = fork // die "fork: $!";
         return if $pid;
@@ -1345,6 +1346,7 @@ sub DESTROY {
         }
         $self->{1}->autoflush(1) if $self->{1};
         stop_pager($self);
+        dump_and_clear_log();
         # preserve $? for ->fail or ->x_it code
 }
 
diff --git a/lib/PublicInbox/LeiStoreErr.pm b/lib/PublicInbox/LeiStoreErr.pm
index 5f9ba24d..cc085fdc 100644
--- a/lib/PublicInbox/LeiStoreErr.pm
+++ b/lib/PublicInbox/LeiStoreErr.pm
@@ -2,7 +2,7 @@
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # forwards stderr from lei/store process to any lei clients using
-# the same store
+# the same store, falls back to syslog if no matching clients exist.
 package PublicInbox::LeiStoreErr;
 use strict;
 use v5.10.1;
@@ -31,7 +31,7 @@ sub event_step {
                 print $err $$rbuf and $printed = 1;
         }
         if (!$printed) {
-                openlog('lei-store', 'pid,nowait,nofatal,ndelay', 'user');
+                openlog('lei/store', 'pid,nowait,nofatal,ndelay', 'user');
                 for my $l (split(/\n/, $$rbuf)) { syslog('warning', '%s', $l) }
                 closelog(); # don't share across fork
         }
diff --git a/t/lei-daemon.t b/t/lei-daemon.t
index a7c4b799..b0c94a87 100644
--- a/t/lei-daemon.t
+++ b/t/lei-daemon.t
@@ -21,14 +21,9 @@ test_lei({ daemon_only => 1 }, sub {
         ok(kill(0, $pid), 'pid is valid');
         ok(-S $sock, 'sock created');
         is(-s $err_log, 0, 'nothing in errors.log');
-        open my $efh, '>>', $err_log or BAIL_OUT $!;
-        print $efh "phail\n" or BAIL_OUT $!;
-        close $efh or BAIL_OUT $!;
-
         lei_ok('daemon-pid');
         chomp(my $pid_again = $lei_out);
         is($pid, $pid_again, 'daemon-pid idempotent');
-        like($lei_err, qr/phail/, 'got mock "phail" error previous run');
 
         SKIP: {
                 skip 'only testing open files on Linux', 1 if $^O ne 'linux';