File: //bin/pg_restorecluster
#!/usr/bin/perl -wT
# pg_restorecluster: restore from a pg_backupcluster backup
#
# Copyright (C) 2021 Christoph Berg <myon@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
use strict;
use warnings;
use Cwd 'abs_path';
use Getopt::Long;
use PgCommon;
my ($version, $cluster);
# untaint environment
$ENV{'PATH'} = '/sbin:/bin:/usr/sbin:/usr/bin';
delete @ENV{'IFS', 'CDPATH', 'ENV', 'BASH_ENV'};
umask 022;
sub help () {
print "Syntax: $0 [options] <version> <cluster> <backup>
Options:
-d --datadir DIR Data directory for restored cluster (default per createcluster.conf)
-p --port PORT Use port PORT for restored cluster (default is next free port)
-s --start Start cluster after restoring (default for restore from dump)
--archive Configure recovery from WAL archive
--pitr TIMEST Configure point-in-time recovery to TIMESTAMP from WAL archive
--wal-archive DIR Read WAL from archive DIR (default <backup>/../wal)
";
}
my $createclusterconf = "$PgCommon::common_confdir/createcluster.conf";
my ($datadir, $port, $start, $recovery_target_time, $archive_recovery, $wal_archive);
exit 1 unless GetOptions (
'd|datadir=s' => \$datadir,
'p|port=s' => \$port,
's|start' => \$start,
'archive' => \$archive_recovery,
'pitr=s' => \$recovery_target_time,
'recovery-target-time=s' => \$recovery_target_time,
'wal-archive=s' => \$wal_archive,
'createclusterconf=s' => \$createclusterconf,
);
if ($recovery_target_time) {
($recovery_target_time) = $recovery_target_time =~ /(.*)/; # untaint
}
# accept both "version cluster" and "version[-/]cluster"
if (@ARGV >= 2 and $ARGV[0] =~ m!^(\d+\.?\d)[-/]([^/]+)$!) {
($version, $cluster) = ($1, $2);
shift @ARGV;
} elsif (@ARGV >= 3 and $ARGV[0] =~ /^(\d+\.?\d)$/) {
$version = $1;
($cluster) = ($ARGV[1]) =~ m!^([^/]+)$!;
shift @ARGV;
shift @ARGV;
} else {
help();
exit 1;
}
error "cluster $version $cluster already exists" if cluster_exists $version, $cluster;
my %defaultconf = PgCommon::read_conf_file ($createclusterconf);
# functions to be run as root
sub create_cluster_directories($$$$) {
my ($owneruid, $ownergid, $configdir, $datadir) = @_;
my @postgres_user = getpwnam 'postgres';
my ($pg_uid, $pg_gid) = (getpwnam 'postgres')[2, 3];
for my $pgdir ("/etc/postgresql", "/etc/postgresql/$version", "/var/lib/postgresql", "/var/lib/postgresql/$version") {
if (! -e $pgdir) {
mkdir $pgdir or error "mkdir $pgdir: $!";
chown $pg_uid, $pg_gid, $pgdir or error "chown $pgdir: $!";
}
}
mkdir $configdir or error "mkdir $configdir: $!";
chown $owneruid, $ownergid, $configdir or error "chown $configdir: $!";
mkdir $datadir, 0700 or error "mkdir $datadir: $!";
chown $owneruid, $ownergid, $datadir or error "chown $datadir: $!";
}
sub create_cluster($$$$$) {
my ($backup, $owneruid, $ownergid, $configdir, $datadir) = @_;
my @createclusteropts = ();
if (-f "$backup/createcluster.opts") {
open my $fh, "$backup/createcluster.opts" or error "$backup/createcluster.opts: $!";
local $/; # slurp mode
my ($opts) = <$fh> =~ /(.*)/; # untaint
@createclusteropts = split /\s+/, $opts;
close $fh;
}
system_or_error "pg_createcluster",
"--datadir", $datadir,
"--user", $owneruid, "--group", $ownergid,
$version, $cluster,
@createclusteropts;
}
sub start_cluster() {
print "Starting cluster $version $cluster ...\n";
system_or_error "pg_ctlcluster", $version, $cluster, "start";
}
sub switch_to_cluster_owner($$) {
my ($owneruid, $ownergid) = @_;
change_ugid $owneruid, $ownergid;
}
# restore functions
sub unpack_tar($$$) {
my ($backup, $tar, $dir) = @_;
if (-f "$backup/$tar.gz") {
$tar = "$tar.gz";
} elsif (-f "$backup/$tar.bz2") {
$tar = "$tar.bz2";
} elsif (-f "$backup/$tar.xz") {
$tar = "$tar.xz";
} elsif (-f "$backup/$tar") {
# do nothing
} else {
error "$backup/config.tar* is missing";
}
print "Restoring $backup/$tar to $dir ...\n";
system_or_error "tar", "-C", $dir, "-xf", "$backup/$tar";
}
sub restore_config($$) {
my ($backup, $configdir) = @_;
unpack_tar($backup, "config.tar", $configdir);
}
sub update_config($$$) {
my ($configdir, $datadir, $port) = @_;
my %settings = (
data_directory => $datadir,
hba_file => "$configdir/pg_hba.conf",
ident_file => "$configdir/pg_ident.conf",
external_pid_file => "/var/run/postgresql/$version-$cluster.pid",
stats_temp_directory => "/var/run/postgresql/$version-$cluster.pg_stat_tmp",
port => $port,
);
$settings{cluster_name} = "$version/$cluster" if ($version >= 9.5);
my %config = PgCommon::read_conf_file("$configdir/postgresql.conf");
for my $guc (sort keys %settings) {
if (not exists $config{$guc} or $config{$guc} ne $settings{$guc}) {
print "Setting $guc = $settings{$guc}\n";
PgCommon::set_conffile_value("$configdir/postgresql.conf", $guc, $settings{$guc});
}
}
}
sub restore_basebackup($$) {
my ($backup, $datadir) = @_;
unpack_tar($backup, "base.tar", $datadir);
}
sub restore_wal($$) {
my ($backup, $datadir) = @_;
return if ($version < 10); # WAL contained in base.tar.gz in PG 9.x
unpack_tar($backup, "pg_wal.tar", "$datadir/pg_wal");
}
sub archive_recovery_options($$$) {
my ($backup, $datadir, $wal_archive) = @_;
$wal_archive = abs_path($wal_archive) or error "$wal_archive: $!";
-d $wal_archive or error "$wal_archive is not a directory";
print "Setting archive recovery options";
my $recovery_options = "restore_command = '/usr/share/postgresql-common/pg_getwal $wal_archive/%f %p'\n";
if ($recovery_target_time) {
$recovery_options .= "recovery_target_time = '$recovery_target_time'\n";
$recovery_options .= "recovery_target_action = 'promote'\n";
}
if ($version >= 12) {
my $autoconf = "$datadir/postgresql.auto.conf";
open my $fh, ">>", $autoconf or error "$autoconf: $!";
print $fh $recovery_options or error "$autoconf: $!";
close $fh or error "$autoconf: $!";
my $recoverysignal = "$datadir/recovery.signal";
open my $fh2, ">", $recoverysignal or error "$recoverysignal: $!";
close $fh2 or error "$recoverysignal: $!";
} else {
my $recoveryconf = "$datadir/recovery.conf";
open my $fh, ">>", $recoveryconf or error "$recoveryconf: $!";
print $fh $recovery_options or error "$recoveryconf: $!";
close $fh or error "$recoveryconf: $!";
}
}
sub reset_archive_recovery_options() {
if ($version >= 12) {
system_or_error "psql",
"--cluster", "$version/$cluster",
"-XAtqc", "ALTER SYSTEM RESET restore_command";
system_or_error "psql",
"--cluster", "$version/$cluster",
"-XAtqc", "ALTER SYSTEM RESET recovery_target_time"
if ($recovery_target_time);
system_or_error "psql",
"--cluster", "$version/$cluster",
"-XAtqc", "ALTER SYSTEM RESET recovery_target_action"
if ($recovery_target_time);
}
}
sub restore_globals($$) {
my ($backup, $owneruid) = @_;
my $owner = (getpwuid $owneruid)[0] or error "UID $owneruid has no name";
print "Restoring $backup/globals.sql ...\n";
open my $globals, "$backup/globals.sql" or error "$backup/globals.sql: $!";
open my $psql, "|-", "psql", "--cluster", "$version/$cluster", "-vON_ERROR_STOP=1", "-Xq" or error "psql: $!";
while (my $line = <$globals>) {
next if ($line eq "CREATE ROLE $owner;\n");
print $psql $line or error "psql: $!";
}
close $globals;
close $psql;
error "psql failed" if ($?);
}
sub create_databases($) {
my ($backup) = @_;
print "Creating databases from $backup/databases.sql ...\n";
system_or_error "psql", "--cluster", "$version/$cluster", "-vON_ERROR_STOP=1", "-Xqf", "$backup/databases.sql";
}
sub restore_dumps($) {
my ($backup) = @_;
for my $dump (sort glob "$backup/*.dump") {
$dump =~ m!(.*/([^/]*).dump)$!;
$dump = $1; # untaint
my $db = $2;
print "Restoring $dump to database $db ...\n";
system_or_error "pg_restore", "--cluster", "$version/$cluster", "-d", $db, $dump;
}
}
sub wait_for_recovery() {
my $sleep = 1;
print "Waiting for end of recovery ...\n";
while (1) {
open my $psql, "-|", "psql", "--cluster", "$version/$cluster", "-XAtc", "SELECT pg_is_in_recovery()" or error "psql: $!";
my $status = <$psql>;
error "psql: $!" unless (defined $status);
close $psql or error "psql: $!";
last if ($status eq "f\n");
sleep($sleep++);
}
}
sub analyze() {
system_or_error "vacuumdb",
"--cluster", "$version/$cluster",
"--analyze-only",
($version >= 9.4 ? "--analyze-in-stages" : ()),
"--all";
}
sub lscluster() {
system_or_error "pg_lsclusters", $version, $cluster;
}
# main
my ($backup) = $ARGV[0] =~ /(.*)/; # untaint
error "$backup is not a directory" unless (-d $backup);
$backup =~ s/\/$//; # strip trailing slash
my ($owneruid, $ownergid) = (stat $backup)[4, 5];
my $configdir = "/etc/postgresql/$version/$cluster";
$datadir //= replace_v_c($defaultconf{data_directory} // "/var/lib/postgresql/%v/%c", $version, $cluster);
($datadir) = $datadir =~ /(.*)/; # untaint
$wal_archive //= "$backup/../wal";
$port //= next_free_port();
if ($backup =~ /\.backup$/) {
create_cluster_directories($owneruid, $ownergid, $configdir, $datadir);
if (fork == 0) {
switch_to_cluster_owner($owneruid, $ownergid);
restore_config($backup, $configdir);
update_config($configdir, $datadir, $port);
restore_basebackup($backup, $datadir);
restore_wal($backup, $datadir);
archive_recovery_options($backup, $datadir, $wal_archive)
if ($archive_recovery or $recovery_target_time);
exit(0);
}
wait;
exit(1) if ($?);
if ($start) {
print "\n";
start_cluster();
switch_to_cluster_owner($owneruid, $ownergid);
wait_for_recovery();
reset_archive_recovery_options() if ($archive_recovery or $recovery_target_time);
analyze();
}
print "\n";
lscluster();
} elsif ($backup =~ /\.dump$/) {
create_cluster($backup, $owneruid, $ownergid, $configdir, $datadir);
print "\n";
if (fork == 0) {
switch_to_cluster_owner($owneruid, $ownergid);
restore_config($backup, $configdir);
update_config($configdir, $datadir, $port);
exit(0);
}
wait;
exit(1) if ($?);
start_cluster();
switch_to_cluster_owner($owneruid, $ownergid);
restore_globals($backup, $owneruid);
create_databases($backup);
restore_dumps($backup);
analyze();
print "\n";
lscluster();
} else {
error "$backup must end in either .backup or .dump";
}
__END__
=head1 NAME
pg_restorecluster - Restore from a pg_backupcluster backup
=head1 SYNOPSIS
B<pg_restorecluster> [I<options>] I<version> I<cluster> I<backup>
=head1 DESCRIPTION
B<pg_restorecluster> restores a PostgreSQL cluster from a backup created by
B<pg_backupcluster>. The cluster will be newly created in the system using the
name provided on the command line; this allows renaming a cluster on restore.
The restored cluster configuration will be updated to reflect the new name and
location.
The I<backup> name passed must end in either B<.basebackup> or B<.dump>;
usually this will be the full path to a backup directory in
C</var/backups/postgresql/version-cluster/> as reported by
B<pg_backupcluster ... list>.
Basebackups are restored as-is. For dumps, B<pg_createcluster> is used to
create a new cluster, and schema and data are restored via B<pg_restore>.
=head1 OPTIONS
=over 4
=item B<-d --datadir> I<DIR>
Use I<DIR> as data directory for the restored cluster (default per
createcluster.conf, by default /var/lib/postgresql/I<version>/I<cluster>).
=item B<-p --port> I<N>
Use port I<N> for restored cluster (default is next free port).
=item B<-s --start>
Start cluster after restoring (default for restore from dump; off for
basebackup restores).
After the cluster has been started, B<ANALYZE> is run on all databases.
=item B<--archive>
Configure cluster for recovery from WAL archive. This sets B<restore_command>
to retrieve WAL files from I<backup>B</../wal>.
=item B<--pitr> I<TIMESTAMP>
=item B<--recovery-target-time> I<TIMESTAMP>
Additionally to setting B<restore_command>, set B<recovery_target_time> to
I<TIMESTAMP> for point-in-time recovery. Also sets
B<recovery_target_action='promote'>.
=item B<--wal-archive> I<DIR>
For archive recovery, read WAL from archive I<DIR> (default is
I<backup>B</../wal>).
=back
=head1 FILES
=over 4
=item /var/backups
Default root directory for cluster backup directories.
=back
See L<pg_backupcluster(1)> for a description of files.
=head1 SEE ALSO
L<pg_backupcluster(1)>, L<pg_restore(1)>, L<vacuumdb(1)>.
=head1 AUTHOR
Christoph Berg L<E<lt>myon@debian.orgE<gt>>