File: //proc/2/root/scripts/ensure_hostname_resolves
#!/usr/local/cpanel/3rdparty/bin/perl
#                                      Copyright 2025 WebPros International, LLC
#                                                           All rights reserved.
# copyright@cpanel.net                                         http://cpanel.net
# This code is subject to the cPanel license. Unauthorized copying is prohibited.
package scripts::ensure_hostname_resolves;
=encoding utf8
=head1 NAME
ensure_hostname_resolves
=head1 DESCRIPTION
Utility that checks to ensure that the hostname resolves to the server.
It can also update the hostname to use an 'autodomain' hostname which is guaranteed to resolve.
=head1 SYNOPSIS
    ensure_hostname_resolves [OPTIONS]
    --yes           Skip the prompts, and assume 'yes'
    --help          This documentation.
=cut
use cPstrict;
use Try::Tiny;
use IO::Prompt                       ();
use Cpanel::Exception                ();
use Cpanel::Hostname                 ();
use Cpanel::IP::Loopback             ();
use Whostmgr::Hostname               ();
use Cpanel::Domain::ExternalResolver ();
use constant _OPTIONS => ('yes');
use parent qw( Cpanel::HelpfulScript );
exit __PACKAGE__->new(@ARGV)->run() unless caller();
sub run ($self) {
    die Cpanel::Exception::create('RootRequired')->to_string_no_id() unless ( $> == 0 && $< == 0 );
    my $hostname_resolves_local;
    try {
        if ( $hostname_resolves_local = $self->hostname_resolves() ) {
            print "[+] Hostname resolves to the server.\n";
        }
        else {
            print "[!] Hostname does NOT resolve to the server.\n";
        }
    }
    catch {
        my $str = Cpanel::Exception::get_string($_);
        print "[!] Failed to determine if hostname resolves to the server: $str\n";
    };
    return 0 if $hostname_resolves_local;
    if ( $self->getopt('yes') || $self->prompt_yn() ) {
        print "[*] Configuring auto-resolving hostname...\n";
        my $new_hostname = Whostmgr::Hostname::set_autodomain_hostname();
        print "[+] Successfully updated hostname to auto-resolving hostname: $new_hostname\n";
    }
    return 0;
}
sub hostname_resolves ($self) {
    my $hostname = Cpanel::Hostname::gethostname(1);
    return 0 if Cpanel::IP::Loopback::is_loopback($hostname);
    return Cpanel::Domain::ExternalResolver::domain_is_on_local_server($hostname);
}
sub prompt_yn ($self) {
    return IO::Prompt::prompt(
        '-yes',
        '-one_char',
        '[*] Do you want the system to update the hostname to an auto-resolving hostname? [y/n] '
    );
}
1;