public-inbox-init: honor umask when creating config file

Creating config 0600 disregarding umask breaks scenarios where daemons
run with credentials different from config owner (but need to read the
config).

File::Temp defaults to 0600, which is unsuitable for the
recommended/typical scenario of daemons running unprivileged and with
UID different from $PI_CONFIG owner, as the deamons need to read
$PI_CONFIG.

Respecting umask might end up creating world-unreadable config, too,
but for people who use such umask that's expected behavior.

1 files changed, 6 insertions, 7 deletions

diff --git a/script/public-inbox-init b/script/public-inbox-init
index 5de45781..b3a16cfb 100755
--- a/script/public-inbox-init
+++ b/script/public-inbox-init
@@ -1,5 +1,5 @@
 #!perl -w
-# Copyright (C) 2014-2021 all contributors <meta@public-inbox.org>
+# Copyright (C) all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 use strict;
 use v5.10.1;
@@ -122,7 +122,8 @@ sysopen($lockfh, $lockfile, O_RDWR|O_CREAT|O_EXCL) or do {
 };
 require PublicInbox::OnDestroy;
 my $auto_unlink = PublicInbox::OnDestroy->new($$, sub { unlink $lockfile });
-my ($perm, %seen);
+my $perm = 0644 & ~umask;
+my %seen;
 if (-e $pi_config) {
         open(my $oh, '<', $pi_config) or die "unable to read $pi_config: $!\n";
         my @st = stat($oh);
@@ -219,7 +220,7 @@ if (sysopen $fh, $f, O_CREAT|O_EXCL|O_WRONLY) {
 }
 
 # needed for git prior to v2.1.0
-umask(0077) if defined $perm;
+umask(0077);
 
 require PublicInbox::Spawn;
 PublicInbox::Spawn->import(qw(run_die));
@@ -246,10 +247,8 @@ for my $kv (@c_extra) {
 }
 
 # needed for git prior to v2.1.0
-if (defined $perm) {
-        chmod($perm & 07777, $pi_config_tmp) or
-                        die "(f)chmod failed on future $pi_config: $!\n";
-}
+chmod($perm & 07777, $pi_config_tmp) or
+        die "(f)chmod failed on future $pi_config: $!\n";
 
 rename $pi_config_tmp, $pi_config or
         die "failed to rename `$pi_config_tmp' to `$pi_config': $!\n";