#!/usr/bin/perl -wT

# Upgrade a PostgreSQL cluster to a newer major version.
#
# (C) 2005-2009 Martin Pitt <mpitt@debian.org>
# (C) 2013 Peter Eisentraut <petere@debian.org>
# (C) 2013-2022 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 PgCommon;
use File::Temp qw(tempfile);
use Getopt::Long;
use POSIX qw(lchown);

# untaint environment
$ENV{'PATH'} = '/bin:/usr/bin';
delete @ENV{'IFS', 'CDPATH', 'ENV', 'BASH_ENV'};

# global variables
my ($version, $newversion, $cluster, $newcluster);
my (%info, %newinfo);
my ($encoding, $old_lc_ctype, $old_lc_collate); # old cluster encoding
my $maintenance_db = 'template1';

# do not trip over cwd not being accessible to postgres superuser
chdir '/';

# update the new cluster's conffiles
sub adapt_conffiles {
    my ($newversion, $newcluster, $configfile) = @_;
    my %c = read_cluster_conf_file $newversion, $newcluster, $configfile;

    # Arguments: <ref to conf hash> <name> <comment>
    my $deprecate = sub {
        my ($conf, $guc, $comment) = @_;
        if (defined $conf->{$guc}) {
            PgCommon::disable_conf_value $newversion, $newcluster,
                $configfile, $guc, $comment;
        }
    };

    # Arguments: <ref to conf hash> <old name> <new name>
    my $rename = sub {
        my ($conf, $old, $new) = @_;
        if (defined ${$conf}{$old}) {
            PgCommon::replace_conf_value $newversion, $newcluster,
                $configfile, $old, "deprecated in favor of $new",
                $new, ${$conf}{$old};
        }
    };

    # Arguments: <config option> <value>
    my $set = sub {
        my ($guc, $val) = @_;
        PgCommon::set_conf_value $newversion, $newcluster, $configfile,
            $guc, $val;
    };

    # adapt paths to configuration files
    if ($configfile eq 'postgresql.conf') {
        $set->('data_directory', $newinfo{'pgdata'});
    } else {
        # fix bug in pg_upgradecluster 200..202
        $deprecate->(\%c, 'data_directory', 'not valid in postgresql.auto.conf');
    }
    for my $guc (qw(hba_file ident_file external_pid_file stats_temp_directory)) {
        next unless (defined $c{$guc});
        my $val = $c{$guc};
        $val =~ s/\b\Q$version\E\b/$newversion/g;
        $val =~ s/\b\Q$cluster\E\b/$newcluster/g if ($cluster ne $newcluster);
        $set->($guc, $val);
    }

    if ($newversion >= '8.2') {
        # preload_libraries -> shared_preload_libraries transition
        $rename->(\%c, 'preload_libraries', 'shared_preload_libraries');

	# australian_timezones -> timezone_abbreviations transition
	my $australian_timezones = config_bool $c{'australian_timezones'};
	if (defined $australian_timezones) {
            PgCommon::replace_conf_value $newversion, $newcluster, $configfile,
		    'australian_timezones', 'deprecated in favor of timezone_abbreviations', 
		    'timezone_abbreviations', ($australian_timezones ?  'Australia' : 'Default');
	}
    }

    if ($newversion >= '8.3') {
        $deprecate->(\%c, 'bgwriter_lru_percent', 'deprecated');
        $deprecate->(\%c, 'bgwriter_all_percent', 'deprecated');
        $deprecate->(\%c, 'bgwriter_all_maxpages', 'deprecated');

        $rename->(\%c, 'redirect_stderr', 'logging_collector');

        $rename->(\%c, 'stats_command_string', 'track_activities');
        $deprecate->(\%c, 'stats_start_collector', 'deprecated, always on now');
        $deprecate->(\%c, 'stats_reset_on_server_start', 'deprecated');

	# stats_block_level and stats_row_level are merged into track_counts
	if ($c{'stats_block_level'} || $c{'stats_row_level'}) {
	    $deprecate->(\%c, 'stats_block_level', 'deprecated in favor of track_counts');
	    $deprecate->(\%c, 'stats_row_level', 'deprecated in favor of track_counts');
            $set->('track_counts', (config_bool $c{'stats_block_level'} || config_bool $c{'stats_row_level'}) ? 'on' : 'off');
	}

        # archive_command now has to be enabled explicitly
        if ($c{'archive_command'}) {
            $set->('archive_mode', 'on');
        }
    }

    if ($newversion >= '8.4') {
        $deprecate->(\%c, 'max_fsm_pages', 'not needed anymore');
        $deprecate->(\%c, 'max_fsm_relations', 'not needed anymore');
        $deprecate->(\%c, 'krb_server_hostname', 'does not exist anymore');
        $deprecate->(\%c, 'krb_realm', 'does not exist anymore');
        $rename->(\%c, 'explain_pretty_print', 'debug_pretty_print');
    }

    if ($newversion >= '9.0') {
	$deprecate->(\%c, 'add_missing_from', 'does not exist anymore');
	$deprecate->(\%c, 'regex_flavor', 'does not exist anymore');
    }

    if ($newversion >= '9.2') {
	$deprecate->(\%c, 'wal_sender_delay', 'does not exist anymore');
	$deprecate->(\%c, 'silent_mode', 'does not exist anymore');
	$deprecate->(\%c, 'custom_variable_classes', 'does not exist anymore');
    }

    if ($newversion >= '9.3') {
        $rename->(\%c, 'unix_socket_directory', 'unix_socket_directories');
        $rename->(\%c, 'replication_timeout', 'wal_sender_timeout');
    }

    if ($newversion >= '9.4') {
        $deprecate->(\%c, 'krb_srvname', 'native krb5 authentication deprecated in favor of GSSAPI');
        # grab dsmt from the new config just written by initdb
        if (not $c{dynamic_shared_memory_type} and $configfile eq 'postgresql.conf') {
            $set->('dynamic_shared_memory_type', ($newinfo{config}->{dynamic_shared_memory_type} || 'mmap'));
        }
    }

    if ($newversion >= '9.5') {
        if (exists $c{checkpoint_segments}) {
            my $max_wal_size = 16*$c{checkpoint_segments} . 'MB';
            $rename->(\%c, 'checkpoint_segments', 'max_wal_size');
            $set->('max_wal_size', $max_wal_size);
        }
        $deprecate->(\%c, 'ssl_renegotiation_limit', 'does not exist anymore');
        # adapt cluster_name
        my $cluster_name = PgCommon::get_conf_value ($newversion, $newcluster, $configfile, 'cluster_name');
        if ($cluster_name) {
            $cluster_name =~ s/\Q$version\E/$newversion/g;
            $cluster_name =~ s/\Q$cluster\E/$newcluster/g;
            $set->('cluster_name', $cluster_name);
        }
    }

    if ($newversion >= '10') {
        $rename->(\%c, 'min_parallel_relation_size', 'min_parallel_table_scan_size');
        $deprecate->(\%c, 'sql_inheritance', 'does not exist anymore');
    }

    if ($newversion >= '11') {
        $deprecate->(\%c, 'replacement_sort_tuples', 'does not exist anymore');
    }

    if ($newversion >= '13') {
        if (exists $c{wal_keep_segments}) {
            my $wal_keep_size = 16*$c{wal_keep_segments} . 'MB';
            $rename->(\%c, 'wal_keep_segments', 'wal_keep_size');
            $set->('wal_keep_size', $wal_keep_size);
        }
    }

    if ($newversion >= '14') {
        $deprecate->(\%c, 'operator_precedence_warning', 'does not exist anymore');
        if ($c{password_encryption} and $c{password_encryption} =~ /^(on|off|true|false)$/) {
            $deprecate->(\%c, 'password_encryption', 'password_encryption is not a boolean anymore');
        }
        $deprecate->(\%c, 'vacuum_cleanup_index_scale_factor', 'does not exist anymore');
    }

    if ($newversion >= '15') {
        $deprecate->(\%c, 'stats_temp_directory', 'does not exist anymore');
    }

    if ($newversion >= '16') {
        $deprecate->(\%c, 'promote_trigger_file', 'does not exist anymore, use pg_promote() instead');
    }
}

sub migrate_config_files() {
    # copy configuration files
    print "Copying old configuration files...\n";
    install_file $info{'configdir'}.'/postgresql.conf', $newinfo{'configdir'},
        $newinfo{'owneruid'}, $newinfo{'ownergid'}, "644";
    adapt_conffiles $newversion, $newcluster, 'postgresql.conf';
    # copy auto.conf after postgresql.conf has been updated
    # (otherwise read_cluster_conf_file would also read auto.conf)
    if ($version >= 9.4) {
        install_file $info{'pgdata'}.'/postgresql.auto.conf', $newinfo{'pgdata'},
            $newinfo{'owneruid'}, $newinfo{'ownergid'}, "600";
        adapt_conffiles $newversion, $newcluster, 'postgresql.auto.conf';
    }
    install_file $info{'configdir'}.'/pg_ident.conf', $newinfo{'configdir'},
        $newinfo{'owneruid'}, $newinfo{'ownergid'}, "640";
    install_file $info{'configdir'}.'/pg_hba.conf', $newinfo{'configdir'},
        $newinfo{'owneruid'}, $newinfo{'ownergid'}, "640";
    if ($version < 8.4 and $newversion >= 8.4) {
        print "Removing 'ident sameuser' from pg_hba.conf...\n";
        my $hba = "$PgCommon::confroot/$newversion/$newcluster/pg_hba.conf";
        open O, $hba or error "open $hba: $!";
        open N, ">$hba.new" or error "open $hba.new: $!";
        while (<O>) {
            s/ident\s+sameuser/ident/;
            print N $_;
        }
        close O;
        close N;
        lchown $newinfo{'owneruid'}, $newinfo{'ownergid'}, "$hba.new";
        chmod 0640, "$hba.new";
        rename "$hba.new", $hba or error "rename: $!";
    }
    if ( -e $info{'configdir'}.'/start.conf') {
        print "Copying old start.conf...\n";
        install_file $info{'configdir'}.'/start.conf', $newinfo{'configdir'},
            $newinfo{'owneruid'}, $newinfo{'ownergid'}, "644";
    }
    if ( -e $info{'configdir'}.'/pg_ctl.conf') {
        print "Copying old pg_ctl.conf...\n";
        install_file $info{'configdir'}.'/pg_ctl.conf', $newinfo{'configdir'},
            $newinfo{'owneruid'}, $newinfo{'ownergid'}, "644";
    }

    # copy SSL files (overwriting any file that pg_createcluster put there)
    for my $file (qw/server.crt server.key root.crt root.crl/) {
        if ( -e "$info{'pgdata'}/$file") {
            print "Copying old $file...\n";
            if (!fork) { # we don't use install_file because that converts symlinks to files
                change_ugid $info{'owneruid'}, $info{'ownergid'};
                system "cp -a $info{'pgdata'}/$file $newinfo{'pgdata'}";
                exit 0;
            }
            wait;
        }
    }
    if ($newversion >= 9.2) {
        # SSL certificate paths have an explicit option now, older versions use
        # a symlink
        for my $f (['server.crt', 'ssl_cert_file'],
            ['server.key', 'ssl_key_file'],
            ['root.crt', 'ssl_ca_file'],
            ['root.crl', 'ssl_crl_file']) {
            my $file = "$newinfo{'pgdata'}/$f->[0]";
            if (-l $file) { # migrate symlink to config entry with link target
                PgCommon::set_conf_value $newversion, $newcluster, 'postgresql.conf',
                    $f->[1], (readlink $file);
                unlink $file;
            } elsif (-e $file) { # plain file in data dir, put in config
                PgCommon::set_conf_value $newversion, $newcluster, 'postgresql.conf',
                    $f->[1], $file;
            }
        }
    }
}

# Write temporary pg_hba.conf.
# Arguments: <version> <cluster> <owner> <owneruid>
sub temp_hba_conf {
    my ($fh, $hba) = tempfile("pg_hba.XXXXXX", TMPDIR => 1, SUFFIX => ".conf");

    if ($_[0] >= '8.4') {
	print $fh "local all $_[2] ident\n";
    } else {
	print $fh "local all $_[2] ident sameuser\n";
    }
    close $fh;
    chmod 0400, $hba;
    lchown $_[3], 0, $hba;

    return $hba;
}

# Get encoding and locales of a running cluster
# Arguments: <version> <cluster>
sub get_encoding {
    my ($version, $cluster) = @_;
    $encoding = get_db_encoding $version, $cluster, $maintenance_db;
    if ($version <= '8.3') {
	($old_lc_ctype, $old_lc_collate) = get_cluster_locales $version, $cluster;
    } else {
	($old_lc_ctype, $old_lc_collate) = get_db_locales $version, $cluster, $maintenance_db;
    }
    unless ($encoding && $old_lc_ctype && $old_lc_collate) {
	error 'could not get cluster locales';
    }
}

# RedHat's run-parts doesn't support any options, supply a minimalistic implementation here
# BUG: we don't care about validating the filenames yet
# Arguments: <directory> <argv to pass to scripts>
sub run_parts {
    my ($dir, @argv) = @_;
    for my $script (<$dir/*>) {
        my ($s) = $script =~ /(.*)/; # untaint
        system ($s, @argv);
        error "$s failed: $?" if ($?);
    }
}


#
# Execution starts here
#

# command line arguments

my $newest_version = get_newest_version('postgres');
$newversion = $newest_version;

my $method = 'dump';
my $link = 0;
my $clone = 0;
my $keep_port = 0;
my $start = -1; # -1 = auto

my ($locale, $lc_collate, $lc_ctype, $lc_messages, $lc_monetary, $lc_numeric,
    $lc_time, $logfile, $old_bindir, $jobs);
GetOptions ('v|version=s' => \$newversion,
	    'locale=s' => \$locale,
	    'lc-collate=s' => \$lc_collate,
	    'lc-ctype=s' => \$lc_ctype,
	    'lc-messages=s' => \$lc_messages,
	    'lc-monetary=s' => \$lc_monetary,
	    'lc-numeric=s' => \$lc_numeric,
	    'lc-time=s' => \$lc_time,
	    'logfile=s' => \$logfile,
	    'm|method=s' => \$method,
	    'j|jobs=s', => \$jobs,
	    'k|link' => \$link,
            'clone' => \$clone,
            'keep-port' => \$keep_port,
            'rename=s' => \$newcluster,
            'old-bindir=s' => \$old_bindir,
            'maintenance-db=s' => \$maintenance_db,
            'start!' => \$start,
    ) or exit 1;

if ($method eq 'dump') {
    error 'cannot use --link with --method=dump' if ($link);
    error 'cannot use --clone with --method=dump' if ($clone);
    error 'cannot use --jobs with --method=dump' if ($jobs);
} elsif ($method eq 'link') {
    $method = 'upgrade';
    $link = 1;
} elsif ($method eq 'clone') {
    $method = 'upgrade';
    $clone = 1;
} elsif ($method ne 'upgrade') {
    error 'method must be "dump", "upgrade", "link", or "clone"';
}

# untaint
($newversion) = $newversion =~ /^(\d+\.?\d+)$/;
($locale) = $locale =~ /^([\w@._-]+)$/ if $locale;
($lc_collate) = $lc_collate =~ /^([\w@._-]+)$/ if $lc_collate;
($lc_ctype) = $lc_ctype =~ /^([\w@._-]+)$/ if $lc_ctype;
($lc_messages) = $lc_messages =~ /^([\w@._-]+)$/ if $lc_messages;
($lc_monetary) = $lc_monetary =~ /^([\w@._-]+)$/ if $lc_monetary;
($lc_numeric) = $lc_numeric =~ /^([\w@._-]+)$/ if $lc_numeric;
($lc_time) = $lc_time =~ /^([\w@._-]+)$/ if $lc_time;
($logfile) = $logfile =~ /^([^\n]+)$/ if $logfile;
($old_bindir) = $old_bindir =~ /^(\/.*)$/ if $old_bindir;
($maintenance_db) = $maintenance_db =~ /^([\w-]+)$/ if $maintenance_db;
($jobs) = $jobs =~ /^(\d+)$/ if $jobs;

if ($#ARGV < 1) {
    print "Usage: $0 [OPTIONS] <old version> <cluster name> [<new data directory>]\n";
    exit 1;
}

($version) = $ARGV[0] =~ /^(\d+\.?\d+)$/;
($cluster) = $ARGV[1] =~ /^([-.\w]+)$/;
$newcluster ||= $cluster; # use old cluster name by default
($newcluster) = $newcluster =~ /^([-.\w]+)$/;
my $datadir;
($datadir) = $ARGV[2] =~ /(.*)/ if defined $ARGV[2];

error 'specified cluster does not exist' unless cluster_exists $version, $cluster;
%info = cluster_info ($version, $cluster);
validate_cluster_owner \%info;
error 'cluster is disabled' if $info{'start'} eq 'disabled';

error "cluster $version/$cluster is already on version $newversion. " .
    "(The newest version installed on this system is $newest_version.)"
    if ($version eq $newversion and $cluster eq $newcluster);

if (cluster_exists $newversion, $newcluster) {
    error "target cluster $newversion/$newcluster already exists";
}

my $oldcontrol = get_cluster_controldata ($version, $cluster);

my $oldsocket = get_cluster_socketdir $version, $cluster;
my $owner = getpwuid $info{'owneruid'};
error 'could not get name of cluster owner' unless $owner;
my $temp_hba_conf = temp_hba_conf $version, $cluster, $owner, $info{'owneruid'};

# stop old cluster
if ($info{'running'}) {
    get_encoding $version, $cluster;
    print "Stopping old cluster...\n";
    my @argv = ('pg_ctlcluster', $version, $cluster, 'stop');
    error "Could not stop old cluster" if system @argv;
}

if ($method eq 'dump' or ($method eq 'upgrade' and not $info{'running'})) {
    print "Restarting old cluster with restricted connections...\n";
    my @argv = ('pg_ctlcluster',
        ($old_bindir ? ("--bindir=$old_bindir") : ()),
        $version, $cluster, 'start', '-o', "-c hba_file=$temp_hba_conf");
    error "Could not restart old cluster" if system @argv;

    get_encoding $version, $cluster unless ($encoding); # if the cluster was not running before, get encoding now

    if ($method eq 'upgrade') {
	print "Stopping old cluster...\n";
        @argv = ('pg_ctlcluster', $version, $cluster, 'stop');
	error "Could not stop old cluster" if system @argv;
    }
}

# in dump mode, old cluster is running now
# in upgrade mode, old cluster is stopped

my $upgrade_port = next_free_port;

# create new cluster, preserving encoding and locales
my @argv = ('pg_createcluster', '-u', $info{'owneruid'}, '-g', $info{'ownergid'},
    '--socketdir', $info{'socketdir'}, '--port', $upgrade_port, '--no-status',
    $newversion, $newcluster);

push @argv, ('--datadir', $datadir) if $datadir;
push @argv, ('--logfile', $logfile) if $logfile;
push @argv, ('--encoding', $encoding) unless $locale or $lc_ctype;
$lc_ctype ||= $locale || $old_lc_ctype;
$lc_collate ||= $locale || $old_lc_collate;
push @argv, ('--locale', $locale) if $locale;
push @argv, ('--lc-collate', $lc_collate) if $lc_collate;
push @argv, ('--lc-ctype', $lc_ctype) if $lc_ctype;
push @argv, ('--lc-messages', $lc_messages) if $lc_messages;
push @argv, ('--lc-monetary', $lc_monetary) if $lc_monetary;
push @argv, ('--lc-numeric', $lc_numeric) if $lc_numeric;
push @argv, ('--lc-time', $lc_time) if $lc_time;
delete $ENV{'LC_ALL'};
push @argv, ('--', '--data-checksums') if $oldcontrol->{'Data page checksum version'}; # 0 = off
error "Could not create target cluster" if system @argv;
print "\n";

# migrate config files to new cluster before running upgrade
%newinfo = cluster_info($newversion, $newcluster);
migrate_config_files();
set_cluster_port $newversion, $newcluster, $upgrade_port; # use free port during upgrade
%newinfo = cluster_info($newversion, $newcluster); # re-read info after migrate_config_files

if ($method eq 'dump') {
    print "Starting new cluster...\n";
    @argv = ('pg_ctlcluster', $newversion, $newcluster, 'start', '-o', "-c hba_file=$temp_hba_conf");
    error "Could not start target cluster" if system @argv;
}

my $pg_restore = get_program_path 'pg_restore', $newversion;

# check whether upgrade scripts exist
my $upgrade_scripts = (-d "$PgCommon::common_confdir/pg_upgradecluster.d" &&
     ($PgCommon::rpm ? `ls $PgCommon::common_confdir/pg_upgradecluster.d` :
         `run-parts --test $PgCommon::common_confdir/pg_upgradecluster.d`));

# Run upgrade scripts in init phase
if ($upgrade_scripts) {
    print "Running <init> phase upgrade hook scripts...\n";
    if (!fork) {
	change_ugid $info{'owneruid'}, $info{'ownergid'};

        if ($PgCommon::rpm) {
            run_parts ("$PgCommon::common_confdir/pg_upgradecluster.d",
                $version, $newcluster, $newversion, 'init');
            exit;
        }

	@argv = ('run-parts', '--lsbsysinit', '-a', $version, '-a', $newcluster,
	    '-a', $newversion, '-a', 'init',
	    "$PgCommon::common_confdir/pg_upgradecluster.d");
	error "$PgCommon::common_confdir/pg_upgradecluster.d script failed" if system @argv;
        exit 0;
    }
    wait;
    if ($? > 0) {
        print STDERR "Error during running upgrade hooks, removing new cluster\n";
        system 'pg_dropcluster', '--stop', $newversion, $newcluster;
        exit 1;
    }
}

# dump cluster; drop to cluster owner privileges

if (!fork) {
    change_ugid $info{'owneruid'}, $info{'ownergid'};
    my $pg_dumpall = get_program_path 'pg_dumpall', $newversion;
    my $pg_dump = get_program_path 'pg_dump', $newversion;
    my $psql = get_program_path 'psql';
    my $newsocket = get_cluster_socketdir $newversion, $newcluster;

    if ($method eq 'dump') {
	# get list of databases (value = datallowconn)
	my %databases;
	open F, '-|', $psql, '-h', $oldsocket, '-p', $info{'port'},
	    '-F|', '-d', $maintenance_db, '-AXtc',
	    'SELECT datname, datallowconn FROM pg_database' or
	    error 'Could not get pg_database list';
	while (<F>) {
	    chomp;
	    my ($n, $a) = split '\|';
	    $databases{$n} = ($a eq 't');
	}
	close F;
	error 'could not get list of databases' if $?;

	# Temporarily enable access to all DBs, so that we can upgrade them
	for my $db (keys %databases) {
	    next if $db eq 'template0';

	    unless ($databases{$db}) {
		print "Temporarily enabling access to database $db\n";
		(system $psql, '-h', $oldsocket, '-p', $info{'port'}, '-qX',
		    '-d', $maintenance_db, '-c',
		    "BEGIN READ WRITE; UPDATE pg_database SET datallowconn = 't' WHERE datname = '$db'; COMMIT") == 0 or
		    error 'Could not enable access to database';
	    }
	}

	# dump schemas
	print "Roles, databases, schemas, ACLs...\n";
	open SOURCE, '-|', $pg_dumpall, '-h', $oldsocket, '-p', $info{'port'},
	     '-s', '--quote-all-identifiers' or error 'Could not execute pg_dumpall for old cluster';
	my $data = '';
        my $buffer;
	while (read SOURCE, $buffer, 1048576) {
	    $data .= $buffer;
	}
	close SOURCE;
	($? == 0) or exit 1;

	# remove creation of db superuser role to avoid error message
	$data =~ s/^CREATE (ROLE|USER) "\Q$owner\E";\s*$//m;

	# create global objects in target cluster
	open SINK, '|-', $psql, '-h', $newsocket, '-p', $newinfo{'port'},
	    '-qX', '-d', $maintenance_db or
	    error 'Could not execute psql for new cluster';

	# ensure that we can upgrade tables for DBs with default read-only
	# transactions
	print SINK "BEGIN READ WRITE; ALTER USER $owner SET default_transaction_read_only to off; COMMIT;\n";

	print SINK $data;

	close SINK;
	($? == 0) or exit 1;

	
	# Upgrade databases
	for my $db (keys %databases) {
	    next if $db eq 'template0';

	    print "Fixing hardcoded library paths for stored procedures...\n";
	    # starting from 9.0, replace() works on strings; for earlier versions it
	    # works on bytea
	    if ($version >= '9.0') {
		(system $psql, '-h', $oldsocket, '-p', $info{'port'}, '-qX', '-d',
		    $db, '-c', "BEGIN READ WRITE; \
			UPDATE pg_proc SET probin = replace(\
			replace(probin, '/usr/lib/postgresql/lib', '\$libdir'), \
			'/usr/lib/postgresql/$version/lib', '\$libdir'); COMMIT") == 0 or
		    error 'Could not fix library paths';
	    } else {
		(system $psql, '-h', $oldsocket, '-p', $info{'port'}, '-qX', '-d',
		    $db, '-c', "BEGIN READ WRITE; \
			UPDATE pg_proc SET probin = decode(replace(\
		       replace(encode(probin, 'escape'), '/usr/lib/postgresql/lib', '\$libdir'), \
		       '/usr/lib/postgresql/$version/lib', '\$libdir'), 'escape'); COMMIT") == 0 or
		    error 'Could not fix library paths';
	    }

	    print 'Upgrading database ', $db, "...\n";
	    open SOURCE, '-|', $pg_dump, '-h', $oldsocket, '-p', $info{'port'},
		 '-Fc', '--quote-all-identifiers', $db or 
		error 'Could not execute pg_dump for old cluster';

	    # start pg_restore and copy over everything
	    my @restore_argv = ($pg_restore, '-h', $newsocket, '-p',
		$newinfo{'port'}, '--data-only', '-d', $db,
                '--disable-triggers', '--no-data-for-failed-tables');
	    open SINK, '|-', @restore_argv or
		error 'Could not execute pg_restore for new cluster';

            my $buffer;
	    while (read SOURCE, $buffer, 1048576) {
		print SINK $buffer;
	    }
	    close SOURCE;
	    ($? == 0) or exit 1;
	    close SINK;

	    # clean up
	    print 'Analyzing database ', $db, "...\n";
	    (system $psql, '-h', $newsocket, '-p', $newinfo{'port'}, '-qX',
		'-d', $db, '-c', 'ANALYZE') == 0 or
		error 'Could not ANALYZE database';

	    unless ($databases{$db}) {
		print "Disabling access to database $db again\n";
		(system $psql, '-h', $oldsocket, '-p', $info{'port'}, '-qX',
		    '-d', $maintenance_db, '-c',
		    "BEGIN READ WRITE; UPDATE pg_database SET datallowconn = 'f' where datname = '$db'; COMMIT") == 0 or
		    error 'Could not disable access to database in old cluster';
		(system $psql, '-h', $newsocket, '-p', $newinfo{'port'}, '-qX',
		    '-d', $maintenance_db, '-c',
		    "BEGIN READ WRITE; UPDATE pg_database SET datallowconn = 'f' where datname = '$db'; COMMIT") == 0 or
		    error 'Could not disable access to database in new cluster';
	    }
	}

	# reset owner specific override for default read-only transactions
	(system $psql, '-h', $newsocket, '-p', $newinfo{'port'}, '-qX', $maintenance_db, '-c',
	    "BEGIN READ WRITE; ALTER USER $owner RESET default_transaction_read_only; COMMIT;\n") == 0 or
	    error 'Could not reset default_transaction_read_only value for superuser';
    } else {
	# pg_upgrade

	use File::Temp qw(tempdir);

	my $pg_upgrade = get_program_path 'pg_upgrade', $newversion;
        $pg_upgrade or error "pg_upgrade $newversion not found";
	my @argv = ($pg_upgrade,
		 '-b', ($old_bindir || "$PgCommon::binroot$version/bin"),
		 '-B', "$PgCommon::binroot$newversion/bin",
		 '-p', $info{'port'},
		 '-P', $newinfo{'port'},
	    );
        if ($version <= 9.1) {
            push @argv, '-d', $info{pgdata}, '-o', "-D $info{configdir}"; # -o and -D configdir require $newversion >= 9.2
        } else {
            push @argv, '-d', $info{configdir};
        }
        push @argv, '-D', $newinfo{configdir};
	push @argv, "--link" if $link;
	push @argv, "--clone" if $clone;
	push @argv, '-j', $jobs if $jobs;

	# Make a directory for pg_upgrade to store its reports and log
	# files.  It will not be removed.
	my $logdir = tempdir("/var/log/postgresql/pg_upgradecluster-$version-$newversion-$newcluster.XXXX");
	chdir $logdir;

	# Run pg_upgrade.
        print "@argv\n";
	my $status = system @argv;

	# Remove the PID file of the old cluster (normally removed by
	# pg_ctlcluster, but not by pg_upgrade).
	unlink "/var/run/postgresql/$version-$cluster.pid";

	$status == 0 or error "pg_upgrade run failed. Logfiles are in $logdir";
        print "pg_upgrade output scripts are in $logdir\n";
    }

    exit 0;
}

wait;

if ($?) {
    print STDERR "Error during cluster dumping, removing new cluster\n";
    system 'pg_dropcluster', '--stop', $newversion, $newcluster;

    # Restart old cluster to allow connections again (two steps because we started without systemd)
    if (system 'pg_ctlcluster', $version, $cluster, 'stop') {
        error 'could not stop old cluster, please do that manually';
    }
    if (system 'pg_ctlcluster', $version, $cluster, 'start') {
        error 'could not start old cluster, please do that manually';
    }
    exit 1;
}

if ($method eq 'dump') {
    print "Stopping target cluster...\n";
    @argv = ('pg_ctlcluster', $newversion, $newcluster, 'stop');
    error "Could not stop target cluster" if system @argv;

    print "Stopping old cluster...\n";
    @argv = ('pg_ctlcluster', $version, $cluster, 'stop');
    error "Could not stop old cluster" if system @argv;
}

print "Disabling automatic startup of old cluster...\n";
my $startconf = $info{'configdir'}.'/start.conf';
if (open F, ">$startconf") {
    print F "# This cluster was upgraded to a newer major version. The old
# cluster has been preserved for backup purposes, but is not started
# automatically.

manual
";
    close F;
} else {
    error "could not create $startconf: $!";
}

my $free_port = next_free_port;
unless ($keep_port) {
    set_cluster_port $version, $cluster, $upgrade_port;
    set_cluster_port $newversion, $newcluster, $info{port};
    $newinfo{port} = $info{port};
}

# notify systemd that we modified the old start.conf
if (not exists $ENV{'PG_CLUSTER_CONF_ROOT'} and -d '/run/systemd/system' and $> == 0) {
    system 'systemctl daemon-reload';
}

# start cluster if it was running before, or upgrade scripts are present
$start = ($info{running} or $upgrade_scripts) if ($start == -1);
if ($start) {
    print "Starting upgraded cluster on port $newinfo{port}...\n";
    @argv = ('pg_ctlcluster', $newversion, $newcluster, 'start');
    error "Could not start upgraded cluster; please check configuration and log files" if system @argv;
}

# Run upgrade scripts in finish phase
if ($upgrade_scripts) {
    print "Running <finish> phase upgrade hook scripts...\n";
    if (!fork) {
	change_ugid $info{'owneruid'}, $info{'ownergid'};

        if ($PgCommon::rpm) {
            run_parts ("$PgCommon::common_confdir/pg_upgradecluster.d",
                $version, $newcluster, $newversion, 'finish');
            exit;
        }

	@argv = ('run-parts', '--lsbsysinit', '-a', $version, '-a', $newcluster,
	    '-a', $newversion, '-a', 'finish',
	    "$PgCommon::common_confdir/pg_upgradecluster.d");
	error "$PgCommon::common_confdir/pg_upgradecluster.d script failed" if system @argv;
        exit 0;
    }
    wait;
    exit $? >> 8 if ($?);
}

print "\nSuccess. Please check that the upgraded cluster works. If it does,
you can remove the old cluster with
    pg_dropcluster $version $cluster\n\n";

system 'pg_lsclusters', $version, $cluster;
system 'pg_lsclusters', $newversion, $newcluster;

__END__

=head1 NAME

pg_upgradecluster - upgrade an existing PostgreSQL cluster to a new major version.

=head1 SYNOPSIS

B<pg_upgradecluster> [B<-v> I<newversion>] I<oldversion> I<name> [I<newdatadir>]

=head1 DESCRIPTION

B<pg_upgradecluster> upgrades an existing PostgreSQL server cluster (i. e. a
collection of databases served by a B<postgres> instance) to a new version
specified by I<newversion> (default: latest available version).  The
configuration files of the old version are copied to the new cluster and
adjusted for the new version.  The new cluster is set up to use data page
checksums if the old cluster uses them.

The cluster of the old version will be configured to use a previously unused
port since the upgraded one will use the original port. The old cluster is not
automatically removed. After upgrading, please verify that the new cluster
indeed works as expected; if so, you should remove the old cluster with
L<pg_dropcluster(8)>. Please note that the old cluster is set to "manual"
startup mode, in order to avoid inadvertently changing it; this means that it
will not be started automatically on system boot, and you have to use
L<pg_ctlcluster(8)> to start/stop it. See section "STARTUP CONTROL" in
L<pg_createcluster(8)> for details.

The I<newdatadir> argument can be used to specify a non-default data directory
of the upgraded cluster. It is passed to B<pg_createcluster>. If not specified,
this defaults to /var/lib/postgresql/I<newversion>/I<name>.

=head1 OPTIONS

=over 4

=item B<-v> I<newversion>

Set the version to upgrade to (default: latest available).

=item B<--logfile> I<filel>

Set a custom log file path for the upgraded database cluster.

=item B<--locale=>I<locale>

Set the default locale for the upgraded database cluster. If this option is not
specified, the locale is inherited from the old cluster.

When upgrading to PostgreSQL 11 or newer, this option no longer allows
switching the encoding of individual databases. (L<pg_dumpall(1)> was changed to
retain database encodings.)

=item B<--lc-collate=>I<locale>

=item B<--lc-ctype=>I<locale>

=item B<--lc-messages=>I<locale>

=item B<--lc-monetary=>I<locale>

=item B<--lc-numeric=>I<locale>

=item B<--lc-time=>I<locale>

Like B<--locale>, but only sets the locale in the specified category.

=item B<-m>, B<--method=>B<dump>|B<upgrade>|B<link>|B<clone>

Specify the upgrade method.  B<dump> uses L<pg_dump(1)> and
L<pg_restore(1)>, B<upgrade> uses L<pg_upgrade(1)>.  The default is
B<dump>.

B<link> and B<clone> are shorthands for B<-m upgrade --link> and B<-m upgrade --clone>,
respectively.

=item B<-k>, B<--link>

In pg_upgrade mode, use hard links instead of copying files to the new
cluster.  This option is merely passed on to pg_upgrade.  See
L<pg_upgrade(1)> for details.

=item B<--clone>

In pg_upgrade mode, use efficient file cloning (also known as "reflinks"
on some systems) instead of copying files to the new cluster. This option
is merely passed on to pg_upgrade.  See L<pg_upgrade(1)> for details.

=item B<-j>, B<--jobs>

In pg_upgrade mode, number of simultaneous processes to use. This
option is merely passed on to pg_upgrade. See L<pg_upgrade(1)>
for details.

=item B<--keep-port>

By default, the old cluster is moved to a new port, and the new cluster is
moved to the original port so clients will see the upgraded cluster. This
option disables that.

=item B<--rename=>I<new cluster name>

Use a different name for the upgraded cluster.

=item B<--old-bindir=>I<directory>

Passed to B<pg_upgrade>.

=item B<--maintenance-db=>I<database>

Database to connect to for maintenance queries.  The default is B<template1>.

=item B<--[no-]start>

Start the new database cluster after upgrading. The default is to start the new
cluster if the old cluster was running, or if upgrade hook scripts are present.

=back

=head1 HOOK SCRIPTS

Some PostgreSQL extensions like PostGIS need metadata in auxiliary tables which
must not be upgraded from the old version, but rather initialized for the new
version before copying the table data. For this purpose, extensions (as well as
administrators, of course) can drop upgrade hook scripts into 
C</etc/postgresql-common/pg_upgradecluster.d/>. Script file names must consist
entirely of upper and lower case letters, digits, underscores, and hyphens; in
particular, dots (i. e. file extensions) are not allowed.

Scripts in that directory will be called with the following arguments:

<old version> <cluster name> <new version> <phase>

Phases:

=over

=item B<init>

A virgin cluster of version I<new version> has been created, i. e.  this new
cluster will already have B<template1> and B<postgres>, but no user databases. Please note that
you should not create tables in this phase, since they will be overwritten by
the dump/restore or B<pg_upgrade> operation.

=item B<finish>

All data from the old version cluster has been dumped/reloaded into the new
one. The old cluster still exists, but is not running.

=back

Failing scripts will abort the upgrade.
The scripts are called as the user who owns the database.

=head1 SEE ALSO

L<pg_createcluster(8)>, L<pg_dropcluster(8)>, L<pg_lsclusters(1)>, L<pg_wrapper(1)>

=head1 AUTHORS

Martin Pitt L<E<lt>mpitt@debian.orgE<gt>>, Christoph Berg L<E<lt>myon@debian.orgE<gt>>