tor-browser-build/tools/update-responses/update_responses

#!/usr/bin/perl -w

use strict;
use feature "state";
use English;
use FindBin;
use YAML::XS qw(LoadFile);
use File::Slurp;
use File::Path qw(make_path);
use Digest::SHA qw(sha256_hex);
use XML::Writer;
use Cwd;
use File::Copy;
use File::Temp;
use File::Find;
use POSIX qw(setlocale LC_ALL);
use IO::CaptureOutput qw(capture_exec);
use Parallel::ForkManager;
use File::Basename;
use XML::LibXML '1.70';
use LWP::Simple;
use JSON;

# Set umask and locale to provide a consistent environment for MAR file
# generation, etc.
umask(0022);
$ENV{"LC_ALL"} = "C";
setlocale(LC_ALL, "C");

my $htdocsdir = "$FindBin::Bin/htdocs";
my $config = LoadFile("$FindBin::Bin/config.yml");
my %htdocsfiles;
my $releases_dir = $config->{releases_dir};
$releases_dir = "$FindBin::Bin/$releases_dir" unless $releases_dir =~ m/^\//;
my @check_errors;
my $initPATH = $ENV{PATH};
my $initLD_LIBRARY_PATH = $ENV{LD_LIBRARY_PATH};

sub exit_error {
    print STDERR "Error: ", $_[0], "\n";
    chdir '/';
    exit (exists $_[1] ? $_[1] : 1);
}

sub get_tmpdir {
    my ($config) = @_;
    return File::Temp->newdir($config->{tmp_dir} ?
                                (DIR => $config->{tmp_dir})
                                : ());
}

sub build_targets_by_os {
    return ($_[0]) unless $config->{build_targets}{$_[0]};
    my $r = $config->{build_targets}{$_[0]};
    return ref $r eq 'ARRAY' ? @$r : ($r);
}

sub get_nbprocs {
    return $ENV{NUM_PROCS} if defined $ENV{NUM_PROCS};
    if (-f '/proc/cpuinfo') {
        return scalar grep { m/^processor\s+:\s/ } read_file '/proc/cpuinfo';
    }
    return 4;
}

sub write_htdocs {
    my ($channel, $file, $content) = @_;
    mkdir $htdocsdir unless -d $htdocsdir;
    mkdir "$htdocsdir/$channel" unless -d "$htdocsdir/$channel";
    write_file("$htdocsdir/$channel/$file", $content);
    $htdocsfiles{$channel}->{$file} = 1;
}

sub clean_htdocs {
    my (@channels) = @_;
    foreach my $channel (@channels) {
        opendir(my $d, "$htdocsdir/$channel");
        my @files = grep { ! $htdocsfiles{$channel}->{$_} } readdir $d;
        closedir $d;
        unlink map { "$htdocsdir/$channel/$_" } @files;
    }
}

sub get_sha512_hex_of_file {
    my ($file) = @_;
    my $sha = Digest::SHA->new("512");
    $sha->addfile($file);
    return $sha->hexdigest;
}

sub get_version_files {
    my ($config, $version) = @_;
    return if $config->{versions}{$version}{files};
    my $appname = $config->{appname_marfile};
    my $files = {};
    my $vdir = version_dir($config, $version);
    my $download_url = "$config->{download}{mars_url}/$version";
    opendir(my $d, $vdir) or exit_error "Error opening directory $vdir";
    foreach my $file (readdir $d) {
        next unless -f "$vdir/$file";
        if ($file =~ m/^$appname-([^-]+)-${version}_(.+)\.mar$/) {
            my ($os, $lang) = ($1, $2);
            $files->{$os}{$lang}{complete} = {
                type => 'complete',
                URL => "$download_url/$file",
                size => -s "$vdir/$file",
                hashFunction => 'SHA512',
                hashValue => get_sha512_hex_of_file("$vdir/$file"),
            };
            next;
        }
        if ($file =~ m/^$appname-([^-]+)-(.+)-${version}_(.+)\.incremental\.mar$/) {
            my ($os, $from_version, $lang) = ($1, $2, $3);
            $files->{$os}{$lang}{partial}{$from_version} = {
                type => 'partial',
                URL => "$download_url/$file",
                size => -s "$vdir/$file",
                hashFunction => 'SHA512',
                hashValue => get_sha512_hex_of_file("$vdir/$file"),
            }
        }
    }
    closedir $d;
    $config->{versions}{$version}{files} = $files;
}

sub get_version_downloads {
    my ($config, $version) = @_;
    my $downloads = {};
    my $vdir = version_dir($config, $version);
    my $download_url = "$config->{download}{bundles_url}/$version";
    opendir(my $d, $vdir) or exit_error "Error opening directory $vdir";
    foreach my $file (readdir $d) {
        next unless -f "$vdir/$file";
        my ($os, $lang);
        if ($file =~ m/^$config->{appname_bundle_osx}-$version-osx64_(.+).dmg$/) {
            ($os, $lang) = ('osx64', $1);
        } elsif ($file =~ m/^$config->{appname_bundle_linux}-(linux32|linux64)-${version}_(.+).tar.xz$/) {
            ($os, $lang) = ($1, $2);
        } elsif ($file =~ m/^$config->{appname_bundle_win64}-${version}_(.+).exe$/) {
            ($os, $lang) = ('win64', $1);
        } elsif ($file =~ m/^$config->{appname_bundle_win32}-${version}_(.+).exe$/) {
            ($os, $lang) = ('win32', $1);
        } else {
            next;
        }
        $downloads->{$os}{$lang} = {
            binary => "$download_url/$file",
            sig => "$download_url/$file.asc",
        };
    }
    closedir $d;
    $config->{versions}{$version}{downloads} = $downloads;
}

sub extract_mar {
    my ($mar_file, $dest_dir, $compression) = @_;
    my $old_cwd = getcwd;
    mkdir $dest_dir;
    chdir $dest_dir or exit_error "Cannot enter $dest_dir";
    my $res = system('mar', '-x', $mar_file);
    exit_error "Error extracting $mar_file" if $res;
    if ($compression ne 'bzip2' && $compression ne 'xz') {
        exit_error "Unknown compression format $compression";
    }
    my $compr_ext = $compression eq 'bzip2' ? 'bz2' : 'xz';
    my $compr_cmd = $compression eq 'bzip2' ? 'bunzip2' : 'unxz';
    my $uncompress_file = sub {
        return unless -f $File::Find::name;
        rename $File::Find::name, "$File::Find::name.$compr_ext";
        system($compr_cmd, "$File::Find::name.$compr_ext") == 0
                || exit_error "Error decompressing $File::Find::name";
    };
    find($uncompress_file, $dest_dir);
    my $manifest = -f 'updatev3.manifest' ? 'updatev3.manifest'
                        : 'updatev2.manifest';
    my @lines = read_file($manifest) if -f $manifest;
    foreach my $line (@lines) {
        if ($line =~ m/^addsymlink "(.+)" "(.+)"$/) {
            exit_error "$mar_file: Could not create symlink $1 -> $2"
                unless symlink $2, $1;
        }
    }
    chdir $old_cwd;
}

sub mar_filename {
    my ($config, $appname, $version, $os, $lang) = @_;
    version_dir($config, $version) .  "/$appname-$os-${version}_$lang.mar";
}

sub create_incremental_mar {
    my ($config, $pm, $from_version, $new_version, $os, $lang, $channel) = @_;
    my $appname = $config->{appname_marfile};
    my $mar_file = "$appname-$os-${from_version}-${new_version}_$lang.incremental.mar";
    my $mar_file_path = version_dir($config, $new_version) . '/' . $mar_file;
    if ($ENV{MAR_SKIP_EXISTING} && -f $mar_file_path) {
        print "Skipping $mar_file\n";
        return;
    }
    print "Starting $mar_file\n";
    my $download_url = "$config->{download}{mars_url}/$new_version";
    my $finished_file = sub {
        exit_error "Error creating $mar_file" unless $_[1] == 0;
        print "Finished $mar_file\n";
        $config->{versions}{$new_version}{files}{$os}{$lang}{partial}{$from_version} = {
            type => 'partial',
            URL => "$download_url/$mar_file",
            size => -s $mar_file_path,
            hashFunction => 'SHA512',
            hashValue => get_sha512_hex_of_file($mar_file_path),
        };
    };
    return if $pm->start($finished_file);
    my $tmpdir = get_tmpdir($config);
    my $mar_c_from = get_config($config, $from_version, $os, 'mar_compression');
    my $mar_c_new = get_config($config, $new_version, $os, 'mar_compression');
    extract_mar(mar_filename($config, $appname, $from_version, $os, $lang),
                "$tmpdir/A", $mar_c_from);
    extract_mar(mar_filename($config, $appname, $new_version, $os, $lang),
                "$tmpdir/B", $mar_c_new);
    # bug 26054: make sure previous macOS version is code signed
    if (!$ENV{NO_CODESIGNATURE} && ($os eq 'osx64')
                && ! -f "$tmpdir/A/Contents/_CodeSignature/CodeResources") {
        exit_error "Missing code signature in $from_version while creating $mar_file";
    }
    if ($ENV{CHECK_CODESIGNATURE_EXISTS}) {
        unless (-f "$tmpdir/A/Contents/_CodeSignature/CodeResources"
            && -f "$tmpdir/B/Contents/_CodeSignature/CodeResources") {
            exit_error "Missing code signature while creating $mar_file";
        }
    }
    local $ENV{MOZ_PRODUCT_VERSION} = $new_version;
    local $ENV{MAR_CHANNEL_ID} = "torbrowser-torproject-$channel";
    local $ENV{TMPDIR} = $tmpdir;
    my ($out, $err, $success) = capture_exec('make_incremental_update.sh',
                                   $mar_file_path, "$tmpdir/A", "$tmpdir/B");
    if (!$success) {
        unlink $mar_file_path if -f $mar_file_path;
        exit_error "making incremental mar:\n" . $err;
    }
    $pm->finish;
}

sub create_incremental_mars_for_version {
    my ($config, $version, $channel) = @_;
    my $pm = Parallel::ForkManager->new(get_nbprocs);
    $pm->run_on_finish(sub { $_[2]->(@_) });
    my $v = $config->{versions}{$version};
    foreach my $from_version (@{$v->{incremental_from}}) {
        $config->{versions}{$from_version} //= {};
        get_version_files($config, $from_version);
        my $from_v = $config->{versions}{$from_version};
        foreach my $os (keys %{$v->{files}}) {
            foreach my $lang (keys %{$v->{files}{$os}}) {
                next unless defined $from_v->{files}{$os}{$lang}{complete};
                create_incremental_mar($config, $pm, $from_version, $version, $os, $lang, $channel);
            }
        }
    }
    $pm->wait_all_children;
}

sub get_config {
    my ($config, $version, $os, $name) = @_;
    return $config->{versions}{$version}{$os}{$name}
        // $config->{versions}{$version}{$name}
        // $config->{$name};
}

sub version_dir {
    my ($config, $version) = @_;
    return get_config($config, $version, 'any', 'releases_dir') . "/$version";
}

sub channel_to_version {
    my ($config, @channels) = @_;
    return values %{$config->{channels}} unless @channels;
    foreach my $channel (@channels) {
        exit_error "Unknown channel $channel"
                unless $config->{channels}{$channel};
    }
    return map { $config->{channels}{$_} } @channels;
}

sub get_buildinfos {
    my ($config, $version) = @_;
    return if exists $config->{versions}{$version}{buildID};
    extract_martools($config, $version);
    my $files = $config->{versions}{$version}{files};
    foreach my $os (keys %$files) {
        foreach my $lang (keys %{$files->{$os}}) {
            next unless $files->{$os}{$lang}{complete};
            my $tmpdir = get_tmpdir($config);
            my $mar_compression = get_config($config, $version, $os, 'mar_compression');
            extract_mar(
                mar_filename($config, $config->{appname_marfile}, $version, $os, $lang),
                "$tmpdir",
                $mar_compression);
            my $appfile = "$tmpdir/application.ini" if -f "$tmpdir/application.ini";
            $appfile = "$tmpdir/Contents/Resources/application.ini"
                                if -f "$tmpdir/Contents/Resources/application.ini";
            exit_error "Could not find application.ini" unless $appfile;
            foreach my $line (read_file($appfile)) {
                if ($line =~ m/^BuildID=(.*)$/) {
                    $config->{versions}{$version}{buildID} = $1;
                    return;
                }
            }
            exit_error "Could not extract buildID from application.ini";
        }
    }
}

sub get_response {
    my ($config, $version, $os, @patches) = @_;
    my $res;
    my $writer = XML::Writer->new(OUTPUT => \$res, ENCODING => 'UTF-8');
    $writer->xmlDecl;
    $writer->startTag('updates');
    if (get_config($config, $version, $os, 'unsupported')) {
        $writer->startTag('update',
            unsupported => 'true',
            detailsURL => get_config($config, $version, $os, 'detailsURL'),
        );
        goto CLOSETAGS;
    }
    my $minversion = get_config($config, $version, $os, 'minSupportedOSVersion');
    my $mininstruc = get_config($config, $version, $os, 'minSupportedInstructionSet');
    $writer->startTag('update',
        type => 'minor',
        displayVersion => $version,
        appVersion => $version,
        platformVersion => get_config($config, $version, $os, 'platformVersion'),
        buildID => get_config($config, $version, $os, 'buildID'),
        detailsURL => get_config($config, $version, $os, 'detailsURL'),
        actions => 'showURL',
        openURL => get_config($config, $version, $os, 'detailsURL'),
        defined $minversion ? ( minSupportedOSVersion => $minversion ) : (),
        defined $mininstruc ? ( minSupportedInstructionSet => $mininstruc ) : (),
    );
    foreach my $patch (@patches) {
        my @sorted_patch = map { $_ => $patch->{$_} } sort keys %$patch;
        $writer->startTag('patch', @sorted_patch);
        $writer->endTag('patch');
    }
    CLOSETAGS:
    $writer->endTag('update');
    $writer->endTag('updates');
    $writer->end;
    return $res;
}

sub write_responses {
    my ($config, @channels) = @_;
    @channels = keys %{$config->{channels}} unless @channels;
    foreach my $channel (@channels) {
        my $version = $config->{channels}{$channel};
        get_version_files($config, $version);
        get_buildinfos($config, $version);
        my $files = $config->{versions}{$version}{files};
        my $migrate_archs = $config->{versions}{$version}{migrate_archs} // {};
        foreach my $old_os (keys %$migrate_archs) {
            my $new_os = $migrate_archs->{$old_os};
            foreach my $lang (keys %{$files->{$new_os}}) {
                $files->{$old_os}{$lang}{complete} =
                        $files->{$new_os}{$lang}{complete};
            }
        }
        foreach my $os (keys %$files) {
            foreach my $lang (keys %{$files->{$os}}) {
                my $resp = get_response($config, $version, $os,
                                $files->{$os}{$lang}{complete});
                write_htdocs($channel, "$version-$os-$lang.xml", $resp);
                foreach my $from_version (keys %{$files->{$os}{$lang}{partial}}) {
                    $resp = get_response($config, $version, $os,
                                $files->{$os}{$lang}{complete},
                                $files->{$os}{$lang}{partial}{$from_version});
                    write_htdocs($channel, "$from_version-$version-$os-$lang.xml", $resp);
                }
            }
        }
        write_htdocs($channel, 'no-update.xml',
            '<?xml version="1.0" encoding="UTF-8"?>'
            . "\n<updates></updates>\n");
    }
}

sub write_htaccess {
    my ($config, @channels) = @_;
    @channels = keys %{$config->{channels}} unless @channels;
    my $flags = "[last]";
    foreach my $channel (@channels) {
        my $htaccess = "RewriteEngine On\n";
        $htaccess .= $config->{htaccess_rewrite_rules}{$channel} // '';
        my $version = $config->{channels}{$channel};
        my $migrate_langs = $config->{versions}{$version}{migrate_langs} // {};
        my $files = $config->{versions}{$version}{files};
        $htaccess .= "RewriteRule ^[^\/]+/$version/ no-update.xml $flags\n";
        foreach my $os (sort keys %$files) {
            foreach my $bt (build_targets_by_os($os)) {
                foreach my $lang (sort keys %{$files->{$os}}) {
                    foreach my $from_version (sort keys %{$files->{$os}{$lang}{partial}}) {
                        $htaccess .= "RewriteRule ^$bt/$from_version/$lang "
                                  .  "$from_version-$version-$os-$lang.xml $flags\n";
                    }
                    $htaccess .= "RewriteRule ^$bt/[^\/]+/$lang "
                              .  "$version-$os-$lang.xml $flags\n";
                }
                foreach my $lang (sort keys %$migrate_langs) {
                    $htaccess .= "RewriteRule ^$bt/[^\/]+/$lang "
                              .  "$version-$os-$migrate_langs->{$lang}.xml $flags\n";
                }
                $htaccess .= "RewriteRule ^$bt/ $version-$os-en-US.xml $flags\n";
            }
        }
        write_htdocs($channel, '.htaccess', $htaccess);
    }
}

sub write_downloads_json {
    my ($config, @channels) = @_;
    return unless $config->{create_downloads_json};
    @channels = keys %{$config->{channels}} unless @channels;
    foreach my $channel (@channels) {
        my $version = $config->{channels}{$channel};
        my $data = {
            version => $version,
            downloads => get_version_downloads($config, $version),
        };
        write_htdocs($channel, 'downloads.json',
            JSON->new->utf8->canonical->encode($data));
    }
}

sub marzip_path {
    my ($config, $version) = @_;
    for my $osname (qw/linux64 linux32 mac64 win64 win32/) {
        my $marzip = version_dir($config, $version) . "/mar-tools-$osname.zip";
        return $marzip if -f $marzip;
    }
    exit_error 'Could not find mar-tools';
}

my $martools_tmpdir;
sub extract_martools {
    my ($config, $version) = @_;
    my $marzip = marzip_path($config, $version);
    $martools_tmpdir = get_tmpdir($config);
    my $old_cwd = getcwd;
    chdir $martools_tmpdir;
    my (undef, undef, $success) = capture_exec('unzip', $marzip);
    chdir $old_cwd;
    exit_error "Error extracting $marzip" unless $success;
    $ENV{PATH} = "$martools_tmpdir/mar-tools:$initPATH";
    if ($initLD_LIBRARY_PATH) {
        $ENV{LD_LIBRARY_PATH} = "$initLD_LIBRARY_PATH:$martools_tmpdir/mar-tools";
    } else {
        $ENV{LD_LIBRARY_PATH} = "$martools_tmpdir/mar-tools";
    }
}

sub log_step {
    my ($url, $step, $status, $details) = @_;
    state $u;
    if (!defined $u || $url ne $u) {
        print "\n" if $u;
        print "$url\n";
        $u = $url;
    }
    print '  ', $step, $status ? ': OK' : ': ERROR',
          $details ? " - $details\n" : "\n";
    return if $status;
    push @check_errors, { url => $url, step => $step, details => $details };
}

sub get_remote_xml {
    my ($url) = @_;
    my $content = get $url;
    log_step($url, 'get', defined $content);
    return undef unless defined $content;
    my $dom = eval { XML::LibXML->load_xml(string => $content) };
    log_step($url, 'parse_xml', defined $dom, $@);
    return $dom;
}

sub check_get_version {
    my ($dom) = @_;
    my @updates = $dom->documentElement()->getChildrenByLocalName('update');
    return undef unless @updates;
    return $updates[0]->getAttribute('appVersion');
}

sub check_no_update {
    my ($dom) = @_;
    my @updates = $dom->documentElement()->getChildrenByLocalName('update');
    return @updates == 0;
}

sub check_has_incremental {
    my ($dom) = @_;
    my @updates = $dom->documentElement()->getChildrenByLocalName('update');
    return undef unless @updates;
    my @patches = $updates[0]->getChildrenByLocalName('patch');
    foreach my $patch (@patches) {
        return 1 if $patch->getAttribute('type') eq 'partial';
    }
    return undef;
}

sub build_targets_list {
    map { ref $_ eq 'ARRAY' ? @$_ : $_ } values %{$config->{build_targets}};
}

sub check_update_responses_channel {
    my ($config, $base_url, $channel) = @_;
    my $channel_version = $config->{channels}{$channel};
    foreach my $build_target (build_targets_list()) {
        foreach my $lang (qw(en-US de)) {
            my $url = "$base_url/$channel/$build_target/1.0/$lang";
            my $dom = get_remote_xml($url);
            if ($dom) {
                my $version = check_get_version($dom);
                log_step($url, 'version', $version eq $channel_version,
                         "expected: $channel_version received: $version");
            }
            $url = "$base_url/$channel/$build_target/$channel_version/$lang";
            $dom = get_remote_xml($url);
            log_step($url, 'no_update', check_no_update($dom)) if $dom;
            my @inc = @{$config->{versions}{$channel_version}{incremental_from}}
                      if $config->{versions}{$channel_version}{incremental_from};
            foreach my $inc_from (@inc) {
                my $url = "$base_url/$channel/$build_target/$inc_from/$lang";
                $dom = get_remote_xml($url);
                next unless $dom;
                my $version = check_get_version($dom);
                log_step($url, 'version', $version eq $channel_version,
                         "expected: $channel_version received: $version");
                log_step($url, 'has_incremental', check_has_incremental($dom));
            }
        }
    }
}

sub download_version {
    my ($config, $version) = @_;
    my $tmpdir = get_tmpdir($config);
    my $destdir = version_dir($config, $version);
    my $urldir = "$config->{download}{archive_url}/$version";
    print "Downloading version $version\n";
    foreach my $file (qw(sha256sums-signed-build.txt sha256sums-signed-build.txt.asc)) {
        if (getstore("$urldir/$file", "$tmpdir/$file") != 200) {
            exit_error "Error downloading $urldir/$file";
        }
    }
    if (system('gpg', '--no-default-keyring', '--keyring',
            "$FindBin::Bin/$config->{download}{gpg_keyring}", '--verify',
            "$tmpdir/sha256sums-signed-build.txt.asc",
            "$tmpdir/sha256sums-signed-build.txt")) {
        exit_error "Error checking gpg signature for version $version";
    }
    make_path $destdir;
    move "$tmpdir/sha256sums-signed-build.txt.asc", "$destdir/sha256sums-signed-build.txt.asc";
    move "$tmpdir/sha256sums-signed-build.txt", "$destdir/sha256sums-signed-build.txt";
    my %sums = map { chomp; reverse split '  ', $_ }
                 read_file "$destdir/sha256sums-signed-build.txt";

    foreach my $file (sort grep { $_ =~ m/\.mar$/ } keys %sums) {
        print "Downloading $file\n";
        exit_error "Error downloading $urldir/$file\n"
                unless getstore("$urldir/$file", "$tmpdir/$file") == 200;
        exit_error "Wrong checksum for $file"
                unless $sums{$file} eq sha256_hex(read_file("$tmpdir/$file"));
        move "$tmpdir/$file", "$destdir/$file";
    }
}

sub download_missing_versions {
    my ($config, @channels) = @_;
    foreach my $channel (@channels) {
        exit_error "Unknown channel $channel"
                unless $config->{channels}{$channel};
        my $cversion = $config->{channels}{$channel};
        next unless $config->{versions}{$cversion}{incremental_from};
        foreach my $version (@{$config->{versions}{$cversion}{incremental_from}}) {
            next if -d version_dir($config, $version);
            download_version($config, $version);
        }
    }
}

sub check_update_responses {
    my ($config) = @_;
    exit_error "usage: $PROGRAM_NAME <base_url> [channels...]" unless @ARGV;
    my ($base_url, @channels) = @ARGV;
    foreach my $channel (@channels ? @channels : keys %{$config->{channels}}) {
        check_update_responses_channel($config, $base_url, $channel);
    }
    if (!@check_errors) {
        print "\n\nNo errors\n";
        return;
    }
    print "\n\nErrors list:\n";
    my $url = '';
    foreach my $error (@check_errors) {
        if ($url ne $error->{url}) {
            $url = $error->{url};
            print "$url\n";
        }
        print "  $error->{step}",
              $error->{details} ? " - $error->{details}\n" : "\n";
    }
}

my %actions = (
    update_responses => sub {
        my ($config) = @_;
        my @channels = @ARGV ? @ARGV : keys %{$config->{channels}};
        foreach my $channel (@channels) {
            exit_error "Unknown channel $channel"
                unless $config->{channels}{$channel};
            $htdocsfiles{$channel} = { '.' => 1, '..' => 1 };
        }
        write_responses($config, @channels);
        write_htaccess($config, @channels);
        write_downloads_json($config, @channels);
        clean_htdocs(@channels);
    },
    gen_incrementals => sub {
        my ($config) = @_;
        foreach my $channel (@ARGV) {
            my ($version) = channel_to_version($config, $channel);
            extract_martools($config, $version);
            get_version_files($config, $version);
            create_incremental_mars_for_version($config, $version, $channel);
        }
    },
    download_missing_versions => sub {
        my ($config) = @_;
        my @channels = @ARGV ? @ARGV : keys %{$config->{channels}};
        download_missing_versions($config, @channels);
    },
    check_update_responses_deployement => \&check_update_responses,
    get_channel_version => sub {
        my ($config) = @_;
        exit_error "Wrong arguments" unless @ARGV == 1;
        exit_error "Unknown channel" unless $config->{channels}{$ARGV[0]};
        print $config->{channels}{$ARGV[0]}, "\n";
    },
);

my $action = fileparse($PROGRAM_NAME);
exit_error "Unknown action $action" unless $actions{$action};
$actions{$action}->($config);