init: implement locking

[public-inbox.git] / script / public-inbox-init

diff --git a/script/public-inbox-init b/script/public-inbox-init
index 2cc704ce78f09970a34c80c67d52caf1abfecd46..8fd2f9dc2f5c490cb8325dbd8b6b74b91febd5be 100755 (executable)
--- a/script/public-inbox-init
+++ b/script/public-inbox-init
@@ -1,29 +1,32 @@
 #!/usr/bin/perl -w
-# Copyright (C) 2014-2018 all contributors <meta@public-inbox.org>
+# Copyright (C) 2014-2019 all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 #
 # Initializes a public-inbox, basically a wrapper for git-init(1)
 use strict;
 use warnings;
-my $usage = "public-inbox-init NAME REPO_DIR HTTP_URL ADDRESS [ADDRESS..]";
+my $usage = "public-inbox-init NAME INBOX_DIR HTTP_URL ADDRESS [ADDRESS..]";
 use Getopt::Long qw/:config gnu_getopt no_ignore_case auto_abbrev/;
 use PublicInbox::Admin;
 PublicInbox::Admin::require_or_die('-base');
 require PublicInbox::Config;
-require PublicInbox::Inbox;
+require PublicInbox::InboxWritable;
 use File::Temp qw/tempfile/;
+use PublicInbox::Lock;
 use File::Basename qw/dirname/;
 use File::Path qw/mkpath/;
+use Fcntl qw(:DEFAULT);
 use Cwd qw/abs_path/;
 
 sub x { system(@_) and die join(' ', @_). " failed: $?\n" }
 sub usage { print STDERR "Usage: $usage\n"; exit 1 }
 my $version = undef;
 my $indexlevel = undef;
-my $skip;
-my %opts = ( 'V|version=i' => \$version,
-            'L|indexlevel=s' => \$indexlevel,
-            'S|skip=i' => \$skip,
+my $skip_epoch;
+my %opts = (
+       'V|version=i' => \$version,
+       'L|indexlevel=s' => \$indexlevel,
+       'S|skip|skip-epoch=i' => \$skip_epoch,
 );
 GetOptions(%opts) or usage();
 PublicInbox::Admin::indexlevel_ok_or_die($indexlevel) if defined $indexlevel;
@@ -37,7 +40,29 @@ my %seen;
 my $pi_config = PublicInbox::Config->default_file;
 my $dir = dirname($pi_config);
 mkpath($dir); # will croak on fatal errors
+
+# first, we grab a flock to prevent simultaneous public-inbox-init
+# processes from trampling over each other, or exiting with 255 on
+# O_EXCL failure below.  This gets unlocked automatically on exit:
+my $lock_obj = { lock_path => "$pi_config.flock" };
+PublicInbox::Lock::lock_acquire($lock_obj);
+
+# git-config will operate on this (and rename on success):
 my ($fh, $pi_config_tmp) = tempfile('pi-init-XXXXXXXX', DIR => $dir);
+
+# Now, we grab another lock to use git-config(1) locking, so it won't
+# wait on the lock, unlike some of our internal flock()-based locks.
+# This is to prevent direct git-config(1) usage from clobbering our
+# changes.
+my $lockfile = "$pi_config.lock";
+my $lockfh;
+sysopen($lockfh, $lockfile, O_RDWR|O_CREAT|O_EXCL) or do {
+       $lockfh = undef;
+       warn "could not open config file: $lockfile: $!\n";
+       exit(255);
+};
+END { unlink($lockfile) if $lockfh };
+
 my $perm;
 if (-e $pi_config) {
        open(my $oh, '<', $pi_config) or die "unable to read $pi_config: $!\n";
@@ -104,8 +129,8 @@ if (-f "$mainrepo/inbox.lock") {
 
 $version = 1 unless defined $version;
 
-if ($version == 1 && defined $skip) {
-       die "--skip is only supported for -V2 repos\n";
+if ($version == 1 && defined $skip_epoch) {
+       die "--skip-epoch is only supported for -V2 repos\n";
 }
 
 my $ibx = PublicInbox::Inbox->new({
@@ -116,15 +141,8 @@ my $ibx = PublicInbox::Inbox->new({
        indexlevel => $indexlevel,
 });
 
-if ($version >= 2) {
-       require PublicInbox::V2Writable;
-       PublicInbox::V2Writable->new($ibx, 1)->init_inbox(0, $skip);
-} elsif ($version == 1) {
-       require PublicInbox::V1Writable;
-       PublicInbox::V1Writable->new($ibx, 1)->init_inbox(0, $skip);
-} else {
-       die "Unsupported -V/--version: $version\n";
-}
+my $creat_opt = {};
+PublicInbox::InboxWritable->new($ibx, $creat_opt)->init_inbox(0, $skip_epoch);
 
 # needed for git prior to v2.1.0
 umask(0077) if defined $perm;