clone|lei_mirror: write description in mirrors

Instead of generic "Unnamed repository" or "missing" messages,
show "mirror of $URL" since it seems like a better default when
creating a mirror.

2 files changed, 68 insertions, 18 deletions

diff --git a/lib/PublicInbox/LeiMirror.pm b/lib/PublicInbox/LeiMirror.pm
index c128d13d..fe1cefe2 100644
--- a/lib/PublicInbox/LeiMirror.pm
+++ b/lib/PublicInbox/LeiMirror.pm
@@ -9,6 +9,7 @@ use parent qw(PublicInbox::IPC);
 use IO::Uncompress::Gunzip qw(gunzip $GunzipError);
 use PublicInbox::Spawn qw(popen_rd spawn);
 use File::Temp ();
+use Fcntl qw(SEEK_SET);
 
 sub do_finish_mirror { # dwaitpid callback
         my ($arg, $pid) = @_;
@@ -87,6 +88,27 @@ sub clone_cmd {
         @cmd;
 }
 
+sub _get_txt { # non-fatal
+        my ($self, $endpoint, $file) = @_;
+        my $uri = URI->new($self->{src});
+        my $lei = $self->{lei};
+        my $path = $uri->path;
+        chop($path) eq '/' or die "BUG: $uri not canonicalized";
+        $uri->path("$path/$endpoint");
+        my $cmd = $self->{curl}->for_uri($lei, $uri, '--compressed');
+        my $ce = "$self->{dst}/$file";
+        my $ft = File::Temp->new(TEMPLATE => "$file-XXXX",
+                                UNLINK => 1, DIR => $self->{dst});
+        my $opt = { 0 => $lei->{0}, 1 => $ft, 2 => $lei->{2} };
+        my $cerr = run_reap($lei, $cmd, $opt);
+        return "$uri missing" if ($cerr >> 8) == 22;
+        return "# @$cmd failed (non-fatal)" if $cerr;
+        my $f = $ft->filename;
+        rename($f, $ce) or return "rename($f, $ce): $! (non-fatal)";
+        $ft->unlink_on_destroy(0);
+        undef; # success
+}
+
 # tries the relatively new /$INBOX/_/text/config/raw endpoint
 sub _try_config {
         my ($self) = @_;
@@ -96,24 +118,10 @@ sub _try_config {
                 File::Path::mkpath($dst);
                 -d $dst or die "mkpath($dst): $!\n";
         }
-        my $uri = URI->new($self->{src});
-        my $lei = $self->{lei};
-        my $path = $uri->path;
-        chop($path) eq '/' or die "BUG: $uri not canonicalized";
-        $uri->path($path . '/_/text/config/raw');
-        my $cmd = $self->{curl}->for_uri($lei, $uri, '--compressed');
-        my $ce = "$dst/inbox.config.example";
-        my $f = "$ce-$$.tmp";
-        open(my $fh, '+>', $f) or return $lei->err("open $f: $! (non-fatal)");
-        my $opt = { 0 => $lei->{0}, 1 => $fh, 2 => $lei->{2} };
-        my $cerr = run_reap($lei, $cmd, $opt);
-        if (($cerr >> 8) == 22) { # 404 missing
-                unlink($f) if -s $fh == 0;
-                return;
-        }
-        return $lei->err("# @$cmd failed (non-fatal)") if $cerr;
-        rename($f, $ce) or return $lei->err("rename($f, $ce): $! (non-fatal)");
-        my $cfg = PublicInbox::Config->git_config_dump($f, $lei->{2});
+        my $err = _get_txt($self, qw(_/text/config/raw inbox.config.example));
+        return $self->{lei}->err($err) if $err;
+        my $f = "$self->{dst}/inbox.config.example";
+        my $cfg = PublicInbox::Config->git_config_dump($f, $self->{lei}->{2});
         my $ibx = $self->{ibx} = {};
         for my $sec (grep(/\Apublicinbox\./, @{$cfg->{-section_order}})) {
                 for (qw(address newsgroup nntpmirror)) {
@@ -122,9 +130,28 @@ sub _try_config {
         }
 }
 
+sub set_description ($) {
+        my ($self) = @_;
+        my $f = "$self->{dst}/description";
+        open my $fh, '+>>', $f or die "open($f): $!";
+        seek($fh, 0, SEEK_SET) or die "seek($f): $!";
+        chomp(my $d = do { local $/; <$fh> } // die "read($f): $!");
+        if ($d eq '($INBOX_DIR/description missing)' ||
+                        $d =~ /^Unnamed repository/ || $d !~ /\S/) {
+                seek($fh, 0, SEEK_SET) or die "seek($f): $!";
+                truncate($fh, 0) or die "truncate($f): $!";
+                print $fh "mirror of $self->{src}\n" or die "print($f): $!";
+                close $fh or die "close($f): $!";
+        }
+}
+
 sub index_cloned_inbox {
         my ($self, $iv) = @_;
         my $lei = $self->{lei};
+        my $err = _get_txt($self, qw(description description));
+        $lei->err($err) if $err; # non fatal
+        eval { set_description($self) };
+        warn $@ if $@;
 
         # n.b. public-inbox-clone works w/o (SQLite || Xapian)
         # lei is useless without Xapian + SQLite
diff --git a/t/lei-mirror.t b/t/lei-mirror.t
index 75e25b3f..35b77cf7 100644
--- a/t/lei-mirror.t
+++ b/t/lei-mirror.t
@@ -2,6 +2,7 @@
 # Copyright (C) 2020-2021 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; use PublicInbox::TestCommon;
+use PublicInbox::Inbox;
 require_mods(qw(-httpd lei));
 my $sock = tcp_server();
 my ($tmpdir, $for_destroy) = tmpdir();
@@ -15,6 +16,8 @@ test_lei({ tmpdir => $tmpdir }, sub {
         my $t1 = "$home/t1-mirror";
         lei_ok('add-external', $t1, '--mirror', "$http/t1/", \'--mirror v1');
         ok(-f "$t1/public-inbox/msgmap.sqlite3", 't1-mirror indexed');
+        is(PublicInbox::Inbox::try_cat("$t1/description"),
+                "mirror of $http/t1/\n", 'description set');
 
         lei_ok('ls-external');
         like($lei_out, qr!\Q$t1\E!, 't1 added to ls-externals');
@@ -22,6 +25,9 @@ test_lei({ tmpdir => $tmpdir }, sub {
         my $t2 = "$home/t2-mirror";
         lei_ok('add-external', $t2, '--mirror', "$http/t2/", \'--mirror v2');
         ok(-f "$t2/msgmap.sqlite3", 't2-mirror indexed');
+        ok(-f "$t2/description", 't2 description');
+        is(PublicInbox::Inbox::try_cat("$t2/description"),
+                "mirror of $http/t2/\n", 'description set');
 
         lei_ok('ls-external');
         like($lei_out, qr!\Q$t2\E!, 't2 added to ls-externals');
@@ -109,4 +115,21 @@ SKIP: {
 ok($td->kill, 'killed -httpd');
 $td->join;
 
+{
+        require_ok 'PublicInbox::LeiMirror';
+        my $mrr = { src => 'https://example.com/src/', dst => $tmpdir };
+        my $exp = "mirror of https://example.com/src/\n";
+        my $f = "$tmpdir/description";
+        PublicInbox::LeiMirror::set_description($mrr);
+        is(PublicInbox::Inbox::try_cat($f), $exp, 'description set on ENOENT');
+
+        my $fh;
+        (open($fh, '>', $f) and close($fh)) or xbail $!;
+        PublicInbox::LeiMirror::set_description($mrr);
+        is(PublicInbox::Inbox::try_cat($f), $exp, 'description set on empty');
+        (open($fh, '>', $f) and print $fh "x\n" and close($fh)) or xbail $!;
+        is(PublicInbox::Inbox::try_cat($f), "x\n",
+                'description preserved if non-default');
+}
+
 done_testing;