Current File : //scripts/convert_roundcube_mysql2sqlite
#!/usr/local/cpanel/3rdparty/bin/perl
# cpanel - scripts/convert_roundcube_mysql2sqlite Copyright 2022 cPanel, L.L.C.
# All rights reserved.
# copyright@cpanel.net http://cpanel.net
# This code is subject to the cPanel license. Unauthorized copying is prohibited
package Script::RCube::Mysql2Sqlite;
use strict;
## no critic (RequireUseWarnings)
use Try::Tiny;
use Cpanel::AccessIds::ReducedPrivileges ();
use Cpanel::Config::LoadCpConf ();
use Cpanel::MysqlUtils ();
use Cpanel::DbUtils ();
use Cpanel::MysqlUtils::Connect ();
use Cpanel::MysqlUtils::Command ();
use Cpanel::MysqlRun ();
use Cpanel::Config::LoadUserDomains ();
use Cpanel::Email::RoundCube ();
use Cpanel::Email::RoundCube::DBI ();
use Cpanel::Quota::Temp ();
use Cpanel::PwCache ();
use Cpanel::Logger ();
use Cpanel::Filesys::Home ();
use File::Basename ();
use File::Copy ();
use File::Path ();
use File::Slurper ();
use DBI;
use XML::Simple ();
use IPC::Open3 ();
$XML::Simple::PREFERRED_PARSER = "XML::SAX::PurePerl";
my $sqlite_table_file = '/usr/local/cpanel/base/3rdparty/roundcube/SQL/sqlite.initial.sql';
my $log_file = '/usr/local/cpanel/logs/roundcube_sqlite_convert_log';
my %opts = ( 'alternate_logfile' => $log_file );
my $logger = Cpanel::Logger->new( \%opts );
my $mysql_dbname = 'roundcube';
my $dbh;
# If this updates, then do_all_rcube_xml_to_db() needs to be updated to match
my @dumptables = qw(users identities contacts contactgroups contactgroupmembers calendars caldav_calendars events caldav_events attachments caldav_attachments itipinvitations);
my $time = time();
## if invoked as a script, there is nothing in the call stack
my $invoked_as_script = !caller();
__PACKAGE__->script(@ARGV) if ($invoked_as_script);
sub script {
my ( $package, $opt_user, $opt_dbname ) = @_;
my $cpconf = Cpanel::Config::LoadCpConf::loadcpconf();
my $db_type = 'mysql';
if ( exists $cpconf->{'roundcube_db'} and ( $cpconf->{'roundcube_db'} eq 'sqlite' ) ) {
$db_type = 'sqlite';
}
if ( defined $opt_user ) {
## the optional user arg feature is currently *only* called as a script;
## otherwise, all these exits would check $invoked_as_script
## Transfers.pm is the only user of $opt_user, which it uses in conjunction with $opt_user;
## this changes the global variable $opt_dbname just in time to be used in &init_check
if ( defined $opt_dbname ) {
$mysql_dbname = $opt_dbname;
}
if ( $db_type eq 'sqlite' && init_check($cpconf) ) {
my $wasSuccess = convert_mysql_roundcube_to_sqlite($opt_user);
if ($wasSuccess) {
## Transfers.pm operates over a different dbname, and is responsible for the
## removal of the temporary database
unless ( defined $opt_dbname ) {
Cpanel::Email::RoundCube::archive_and_drop_mysql_roundcube($logger);
}
return 1;
}
die "Conversion for user '$opt_user' was not successful.\n";
}
## SOMEDAY @GOLIVE: update-roundcube-sqlite-db gets moved to update-roundcube-db. Update this message and the conditional @GOIVE.
die "The optional user argument is to be used only when Roundcube has been converted to sqlite. Use bin/update-roundcube-sqlite-db Exiting.\n";
}
## Has the roundcube conversion already happened?
## note: this check is here, and not in init_check, because Transfers.pm calls into this
## from a different context. The src server uses MySQL but the dest machine has done
## the sqlite conversion.
if ( $db_type eq 'sqlite' ) {
$logger->info("Roundcube conversion already occurred, bailing out.");
if ($invoked_as_script) {
exit(0);
}
return 1;
}
unless ( init_check($cpconf) ) {
if ($invoked_as_script) {
exit(0);
}
return 1;
}
my %TRUEDOMAINS;
Cpanel::Config::LoadUserDomains::loadtrueuserdomains( \%TRUEDOMAINS );
my @users = sort values %TRUEDOMAINS;
my $success_cnt = 0;
my $success_verify = scalar @users;
for my $user (@users) {
$success_cnt += convert_mysql_roundcube_to_sqlite($user);
}
unless ( $success_cnt == $success_verify ) {
$logger->warn("Roundcube Mysql to sqlite conversion was not completely successful. Please check $log_file for details.");
if ($invoked_as_script) {
exit(1);
}
return;
}
## Conversion is a success, so switch Roundcube configuration to use SQLite before dropping the database.
my $DIR = '/usr/local/cpanel/base/3rdparty';
Cpanel::Email::RoundCube::generate_roundcube_config_sqlite( $DIR, $logger );
## if the conversion was a complete success (as checked above), we can safely archive and
## delete the MySQL roundcube database. This will prevent future problems with transfers,
## and in fact is the final solution for the original Roundcube case 12162!
## already asserted via &init_check
my $archive_success = Cpanel::Email::RoundCube::archive_and_drop_mysql_roundcube($logger);
require Cpanel::Config::CpConfGuard;
my $cpconf_guard = Cpanel::Config::CpConfGuard->new();
$cpconf->{'roundcube_db'} = $cpconf_guard->{'data'}->{'roundcube_db'} = 'sqlite';
$cpconf_guard->save();
if ($invoked_as_script) {
Cpanel::Email::RoundCube::restart_cpsrvd();
exit(0);
}
return 1;
}
sub convert_mysql_roundcube_to_sqlite {
my ($user) = @_;
my @domains = Cpanel::Email::RoundCube::collect_domains($user);
my @uid_name_pairs = collect_roundcube_user_info( \@domains, $user );
## returning 1: no conversion necessary
return 1 unless ( scalar @uid_name_pairs );
## e.g. '/home'
my $best_mnt_point = Cpanel::Filesys::Home::get_homematch_with_most_free_space();
my $tmpdir_root_base = "$best_mnt_point/roundcube_convert";
if ( -d $tmpdir_root_base ) {
rename( $tmpdir_root_base, "$tmpdir_root_base.$time" );
}
mkdir($tmpdir_root_base);
my $tmpdir_root_sys = "$tmpdir_root_base/$user";
mkdir($tmpdir_root_sys);
my @pwinfo = Cpanel::PwCache::getpwnam($user);
my ( $mmuid, $mmgid, $homedir ) = @pwinfo[ 2, 3, 7 ];
my $tmpdir_emailuser_base = "$homedir/tmp/roundcube_convert";
my $success_cnt = 0;
for my $email_user_info (@uid_name_pairs) {
my ( $uid, $email_user ) = @$email_user_info;
my $tmpdir_root_sys_emailuser = "$tmpdir_root_sys/$email_user";
mkdir($tmpdir_root_sys_emailuser);
do_mysqldumps_for_user( $uid, $tmpdir_root_sys_emailuser );
}
## ensures that $best/rcube/$sysuser/$emailuser is readable by $sysuser,
## so that $sysuser can move it to their $homedir after the setuid
my $tempquota = Cpanel::Quota::Temp->new( user => $user, log => 1 );
$tempquota->disable();
my $rv_chmod = system("chmod -R 700 $tmpdir_root_sys");
my $rv_chown = system("chown -Rf $mmuid:$mmgid $tmpdir_root_sys");
for my $email_user_info (@uid_name_pairs) {
my ( $uid, $email_user ) = @$email_user_info;
chdir($tmpdir_root_base);
my $tmpdir_root_sys_emailuser = "$tmpdir_root_sys/$email_user";
my $rv_convert = xml_to_sqlite( $user, $tmpdir_root_sys_emailuser, $tmpdir_emailuser_base, $email_user, $homedir );
unless ($rv_convert) {
$logger->warn("Conversion was not successful for user '$user'.");
}
$success_cnt += $rv_convert;
## note: no need to "rmdir($tmpdir_root_sys_emailuser)", as this dir was moved
## to $homedir/tmp/rcube/$emailuser (during the setuid)
## SOMEDAY @GOLIVE: remove the mysql roundcube database (steal mysql/roundcube backup/archive
## clauses from update-roundcube-db, the mysql version)
}
$tempquota->restore();
rmdir($tmpdir_root_sys);
rmdir($tmpdir_root_base);
return $success_cnt == scalar(@uid_name_pairs);
}
sub collect_roundcube_user_info {
my ( $ar_domains, $user ) = @_;
my $regexp = '@(' . join( '|', map { s/\./\\./gr } @$ar_domains ) . ')$';
my @ids;
try {
@ids = $dbh->selectall_array( "SELECT user_id, username FROM users WHERE username REGEXP ? or username = ?", {}, $regexp, $user );
};
return @ids;
}
## Stolen from pkgacct; needs to be modularized!
## SOMEDAY: this version has converged; move pkgacct version to module, and get rid of below
sub mysqldumpdb {
my ($args) = @_;
my @options = @{ $args->{'options'} };
my $db = $args->{'db'};
my $table = $args->{'table'};
my $file = $args->{'file'};
my $file_mode = $args->{'append'} ? '>>' : '>';
# for testing
my @extra_options = _get_extra_options();
my $mysqldump = Cpanel::DbUtils::find_mysqldump();
my @db = ($db);
if ($table) {
push @db, $table;
}
my $pid = IPC::Open3::open3( my $w, my $r, '', $mysqldump, @extra_options, @options, @db );
my $first_line = 1;
if ( open( my $fh, $file_mode, $file ) ) {
while (<$r>) {
if ( $first_line && ( !$_ || m/^mysqldump:/ ) ) {
warn join( '.', @db ) . ': ' . $_;
close $w;
close $r;
waitpid( $pid, 0 );
$first_line = 0;
my $mysqlcheck = Cpanel::DbUtils::find_mysqlcheck();
system( $mysqlcheck, '--repair', @extra_options, @db );
$pid = IPC::Open3::open3( $w, $r, '', $mysqldump, @extra_options, @options, @db );
}
else {
print {$fh} $_;
}
}
}
close $w;
close $r;
waitpid( $pid, 0 );
return;
}
sub do_mysqldumps_for_user {
my ( $uid, $tmp_convertdir ) = @_;
for my $tbl (@dumptables) {
## these two tables do not key off user_id
next if grep { $tbl eq $_ } qw{contactgroupmembers events ical_events caldav_events attachments ical_attachments caldav_attachments caldav_calendars};
## XML output, not suppressing table structure, with a where clause on user_id list
my @opts = ( '--xml', '-w', qq{user_id = $uid} );
mysqldumpdb(
{
'options' => [@opts],
'db' => $mysql_dbname,
'file' => "$tmp_convertdir/rcube.$tbl.xml",
'table' => $tbl
}
);
}
## contactgroupmembers is gathered in two steps, otherwise would be a LEFT JOIN that
## &mysqldumpdb can not currently support
my $contacts = _get_ids_from_col( 'contactgroups', 'contactgroup_id', $uid, 'user_id' );
_dump_stuff_in( 'contactgroupmembers', 'contactgroup_id', $contacts, $tmp_convertdir ) if scalar(@$contacts);
# Handle events & attachments for calendaring, as those are identified by
# calendar & event respectively.
foreach my $type (qw{default ical caldav}) {
my $prefix = $type eq 'default' ? '' : "${type}_";
my $cals = _get_ids_from_col( "${prefix}calendars", 'calendar_id', $uid, 'user_id' );
next if !scalar(@$cals);
my @events2export;
my @attachments2export;
foreach my $cal (@$cals) {
my $events = _get_ids_from_col( "${prefix}events", 'event_id', $cal, 'calendar_id' );
# Can't have attachments if no events exist to attach em to, so
# next here is appropriate.
next if !scalar(@$events);
push @events2export, @$events;
my $attachments = _get_ids_from_col( "${prefix}attachments", 'attachment_id', $events, 'event_id' );
next if !scalar(@$attachments);
push @attachments2export, @$attachments;
}
_dump_stuff_in( "${prefix}events", 'event_id', \@events2export, $tmp_convertdir ) if @events2export;
_dump_stuff_in( "${prefix}attachments", 'attachment_id', \@attachments2export, $tmp_convertdir ) if @attachments2export;
}
return undef;
}
# Only here so that I don't "repeat myself".
sub _get_ids_from_col {
my ( $tbl, $col, $search_term, $filter_on, $filter_mode ) = @_;
my @ids;
try {
# Quoting anything other than values here is actually harmful.
# Don't do it as such. Same for IN statement here.
my $where_clause = "WHERE $filter_on = ?";
if ( ref $search_term eq 'ARRAY' ) {
my $count = scalar(@$search_term);
die "Bad call to _get_ids_from_col: no search term specified!" if !$count;
my $qs = ( '?,' x ( $count - 1 ) ) . '?';
$where_clause = "WHERE $filter_on IN ($qs)";
@ids = map { $_->[0] } $dbh->selectall_array( "SELECT $col FROM $tbl $where_clause", {}, @$search_term );
}
else {
@ids = map { $_->[0] } $dbh->selectall_array( "SELECT $col FROM $tbl $where_clause", {}, $search_term );
}
}
catch {
$logger->warn( "Attempt to find necessary data from $col in $tbl failed: " . $dbh->errstr() );
};
return \@ids;
}
# Only here so that I don't "repeat myself".
sub _dump_stuff_in {
my ( $tbl, $col, $in, $tmp_convertdir ) = @_;
my $csv = join( ',', @$in );
mysqldumpdb(
{
'options' => [ '--xml', '-w', qq{$col IN ($csv)} ],
'db' => $mysql_dbname,
'file' => "$tmp_convertdir/rcube.$tbl.xml",
'table' => $tbl,
}
);
return;
}
sub create_rcube_sqlite_tables {
my ($dbh) = @_;
Cpanel::Email::RoundCube::DBI::ensure_schema_update( $dbh, 'sqlite' );
return undef;
}
# This used to do all sorts of things like telling rcube_xml_to_db what needed
# quoting, what needed to be set to NULL, etc. -- thankfully all that is
# absolutely unnecessary with sqlite3.
sub do_all_rcube_xml_to_db {
my ( $dbh, $xmldir ) = @_;
my $success_cnt = 0;
## verify the number of XML docs to convert to SQL
my $success_verify = scalar(@dumptables);
{
## note: there is a disparity in the sqlite.initial.sql, and the "table_structure" for "users";
## preferences is not NULLABLE.
my @_cols = qw(user_id username mail_host created last_login language preferences);
$success_cnt += rcube_xml_to_db( $xmldir, 'users', $dbh, \@_cols );
}
{
my @_cols = qw( identity_id user_id changed del standard name organization email
reply-to bcc signature html_signature);
$success_cnt += rcube_xml_to_db( $xmldir, 'identities', $dbh, \@_cols );
}
{
my @_cols = qw(contact_id user_id changed del name email firstname surname vcard);
$success_cnt += rcube_xml_to_db( $xmldir, 'contacts', $dbh, \@_cols );
}
## new contactgroups table
{
my @_cols = qw( contactgroup_id user_id changed del name );
$success_cnt += rcube_xml_to_db( $xmldir, 'contactgroups', $dbh, \@_cols );
}
## new contactgroupmembers table
## guard clause: contactgroupmembers is gathered conditionally, so it is the only file which
## may not exist
if ( -e _xml_file( $xmldir, 'contactgroupmembers' ) ) {
my @_cols = qw( contactgroup_id contact_id created );
$success_cnt += rcube_xml_to_db( $xmldir, 'contactgroupmembers', $dbh, \@_cols );
}
else {
$success_cnt++;
}
# Restore calendar data
foreach my $cal_tbl (qw{calendars caldav_calendars}) {
unless ( -e _xml_file( $xmldir, $cal_tbl ) ) {
$success_cnt++;
next;
}
my @_cols = qw( calendar_id user_id name color showalarms );
push( @_cols, qw{ical_url ical_user ical_pass ical_last_change} ) if $cal_tbl eq 'ical_calendars';
push( @_cols, qw{readonly caldav_url caldav_tag caldav_user caldav_pass caldav_oauth_provider caldav_last_change} ) if $cal_tbl eq 'caldav_calendars';
$success_cnt += rcube_xml_to_db( $xmldir, $cal_tbl, $dbh, \@_cols );
}
foreach my $evt_tbl (qw{events caldav_events}) {
unless ( -e _xml_file( $xmldir, $evt_tbl ) ) {
$success_cnt++;
next;
}
my @_cols = qw( event_id calendar_id recurrence_id uid instance isexception created changed sequence start end recurrence title description location categories url all_day free_busy priority sensitivity status alarms attendees notifyat );
push( @_cols, qw{ical_url ical_last_change} ) if $evt_tbl eq 'ical_events';
push( @_cols, qw{caldav_url caldav_tag caldav_last_change} ) if $evt_tbl eq 'caldav_events';
$success_cnt += rcube_xml_to_db( $xmldir, $evt_tbl, $dbh, \@_cols );
}
foreach my $atc_tbl (qw{attachments caldav_attachments}) {
unless ( -e _xml_file( $xmldir, $atc_tbl ) ) {
$success_cnt++;
next;
}
my @_cols = qw( attachment_id event_id filename mimetype size data );
$success_cnt += rcube_xml_to_db( $xmldir, $atc_tbl, $dbh, \@_cols );
}
if ( -e _xml_file( $xmldir, 'itipinvitations' ) ) {
my @_cols = qw(token event_uid user_id event expires cancelled);
$success_cnt += rcube_xml_to_db( $xmldir, 'itipinvitations', $dbh, \@_cols );
}
else {
$success_cnt++;
}
return $success_cnt == $success_verify;
}
sub _xml_file {
my ( $xmldir, $tbl ) = @_;
return "$xmldir/rcube.$tbl.xml";
}
sub rcube_xml_to_db {
my ( $xmldir, $tbl, $dbh, $ar_cols ) = @_;
my $xml_fname = _xml_file( $xmldir, $tbl );
my %common_opts = ( ForceArray => 1, KeyAttr => [], ContentKey => '__content' );
## $ref->{database}->[0]->{table_data}->[0]->{row}->[$x]->{field}->[$x]->{__content}
my $ref;
my $err;
try {
$ref = XML::Simple::XMLin( $xml_fname, %common_opts );
}
catch {
$err = $_;
};
if ($err) {
$logger->warn("Failed to load xml for $tbl: $err");
return;
}
my $rows = $ref->{'database'}->[0]->{'table_data'}->[0]->{'row'};
## FWIW, Perl does not complain if $rows is undef, when called in a for loop context.
for my $row (@$rows) {
# XXX Placeholders don't work on columns, but stuff with dashes
# still needs quoting. As such, quote all col names.
# Sorry, couldn't find a way around it.
my $update_hr = { map { $dbh->quote_identifier( $_->{'name'} ) => $_->{'__content'} || '' } @{ $row->{'field'} } };
my $rv = $dbh->do( rcube_make_sql( $tbl, $update_hr ) );
unless ($rv) {
$logger->warn( "Conversion was not successful: " . $dbh->errstr() );
return;
}
}
return 1;
}
sub rcube_make_sql {
my ( $table, $update_hr ) = @_;
# Lets hope these actually are nonzero
my @values = values(%$update_hr);
my $qs = ( '?,' x ( scalar(@values) - 1 ) ) . '?';
return (
"INSERT OR REPLACE INTO $table (" . join( ",", keys(%$update_hr) ) . ") VALUES ($qs)",
undef,
@values,
);
}
sub check_mysqlup {
## note: this call is cached with a ttl of 600
my $isrunning = Cpanel::MysqlRun::running();
if ($isrunning) {
return 1;
}
return undef;
}
sub ensure_roundcube_tables {
my ($dbh) = @_;
my %tables = map { $_ => undef } $dbh->tables();
# system table is created during a migration
my @expected = qw(session cache system);
push( @expected, @dumptables );
for my $exp (@expected) {
if ( !exists $tables{$exp} && !exists $tables{qq{"main"."$exp"}} ) {
$logger->warn("ERROR: missing $exp table");
return;
}
}
return 1;
}
sub init_check {
my ($cpconf) = @_;
## Ensure root
return unless ( 0 == $> );
unless ( -e $sqlite_table_file ) {
$logger->info("Roundcube is not installed; conversion is irrelevant.");
return;
}
if ( exists $cpconf->{'skiproundcube'} and $cpconf->{'skiproundcube'} ) {
$logger->info("Roundcube should be skipped, bailing out.");
return;
}
my $mysqlup = check_mysqlup();
unless ($mysqlup) {
$logger->warn("Mysql not currently running, bailing out.");
return;
}
## Does this installation use Roundcube/MySQL?
unless ( Cpanel::MysqlUtils::Command::db_exists($mysql_dbname) ) {
$logger->warn("mysql database $mysql_dbname is missing");
return;
}
my $error;
try {
my $dbc = Cpanel::MysqlUtils::Connect->new( database => $mysql_dbname );
$dbh = $dbc->db_handle();
}
catch {
$error = $_;
};
if ($error) {
$logger->warn("Failed to connect to MySQL database '$mysql_dbname'.");
return;
}
return 1;
}
##############################################################
# These functions allow tests to use a temporary MySQL server
sub _get_extra_options_string {
if ( scalar _get_extra_options() ) {
return join( ' ', _get_extra_options() );
}
return;
}
sub _get_extra_options {
return @Cpanel::MysqlUtils::_EXTRA_MYSQL_ARGS;
}
#
##############################################################
sub xml_to_sqlite {
my ( $user, $tmpdir_root, $tmpdir_convert_base, $email_user, $homedir ) = @_;
my $code_ref = _closure_maker( $user, $tmpdir_root, $tmpdir_convert_base, $email_user, $homedir );
#fixup a user who's purposefully deleted their "etc" dir
Cpanel::AccessIds::ReducedPrivileges::call_as_user( sub { File::Path::make_path( File::Basename::dirname( _roundcube_db_path( $user, $homedir, $email_user ) ), { chmod => 0750 } ); }, $user, 'mail' );
my $rv = Cpanel::AccessIds::ReducedPrivileges::call_as_user( $code_ref, $user );
return $rv;
}
sub _roundcube_db_path {
my ( $system_user, $homedir, $mail_account ) = @_;
my ( $mail_user, $mail_domain ) = split( '@', $mail_account );
my $db_path = ( defined $mail_domain ) ? "$homedir/etc/$mail_domain/$mail_user.rcube.db" : "$homedir/etc/$mail_user.rcube.db";
return $db_path;
}
## defining as a closure, as ::run_as_user does not currently handle sub args
sub _closure_maker {
my ( $system_user, $tmpdir_root, $tmpdir_convert_base, $email_user, $homedir ) = @_;
my $code_ref = sub {
my $tmp_convertdir = "$tmpdir_convert_base/$email_user";
if ( -d $tmp_convertdir ) {
rename( $tmp_convertdir, "$tmp_convertdir.$time" );
}
# Copy the XML files over to the user's tempdir.
# Hopefully these are simple renames. But directories may be on different
# mount points requiring a copy.
File::Path::make_path($tmp_convertdir);
for my $table (@dumptables) {
my $src = _xml_file( $tmpdir_root, $table );
my $dest = _xml_file( $tmp_convertdir, $table );
if ( -e $src ) {
File::Copy::move( $src, $dest );
}
}
# Clean up empty source directory.
# This will fail if the above moves failed.
rmdir($tmpdir_root);
## note: similar clause in cpsrvd to set up $ENV{'_RCUBE'}
my ( $mail_user, $mail_domain ) = split( '@', $email_user );
my $rcube_sqlite_loc8 = _roundcube_db_path( $system_user, $homedir, $email_user );
if ( -e $rcube_sqlite_loc8 ) {
rename( $rcube_sqlite_loc8, "$rcube_sqlite_loc8.$time" );
}
my $dbh = DBI->connect( "dbi:SQLite:dbname=$rcube_sqlite_loc8", "", "" ) or do {
$logger->info("Connection error to $rcube_sqlite_loc8: $!");
return;
};
## note: $dbh->{sqlite_version} is confirmed 2.8.15
create_rcube_sqlite_tables($dbh);
return unless ensure_roundcube_tables($dbh);
unless ( do_all_rcube_xml_to_db( $dbh, $tmp_convertdir ) ) {
$logger->info("Conversion of roundcube XML dump to sqlite database failed");
return;
}
$dbh->disconnect();
chmod( 0600, $rcube_sqlite_loc8 );
## the return values on these rm calls are not critical
## only remove the /tmp directory if the XML converion has been successful thus far
try {
File::Path::remove_tree($tmp_convertdir);
};
## attempt to rmdir, which will intentionally fail if any of the converts did not succeed
rmdir($tmpdir_convert_base);
return 1;
};
return $code_ref;
}
1;
Mini Shell