You should verify that your bind call goes right. For example with

use Net::LDAP::Util qw(ldap_error_text
                       ldap_error_name) ;

my $msg ; # you will need it several times
$msg = $ldap->bind(%your_bind_params) ;
if ($msg->is_error) {
  my $code = $msg->code ;
  die join "\n",ldap_error_name($code),
                ldap_error_text($code) ;
}
[download]

you will get an idea of what goes wrong.

Next, it seems you don't cycle over the %petra hash, your $dn doesn't depend on the username... how could you get it to put all your users into the directory server?

To put the users in, I'd use something like this untested code, based on yours:

while (my ($username,$userdata) = each %petra) {
  my $entry = Net::LDAP::Entry->new();
  my $dn = calculate_it_using($username) ;

  $entry->dn($dn) ;
  $entry->changetype("add");
  $entry->add(@$userdata) ;

  $msg = $entry->update($ldap) ;
  if ($msg->is_error) {
    # die() the same way as before. I'd suggest
    # to create a subroutine to do the job, e.g.
    # die_ldap_error($msg->code)
  }
}
[download]

I seldom use that syntax anyway. I prefer using $ldap->add($entry) instead. But that's a matter of taste :-)

Ciao!
--bronto

# Another Perl edition of a song:
# The End, by The Beatles
END {
  $you->take($love) eq $you->make($love) ;
}