#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
use Net::OpenSSH::Parallel;

# $Net::OpenSSH::Parallel::debug = -1;

my %hosts = ( 'localhost' => { host  => "localhost",
			       user  => "user",
			       port  => "22", # default
			       # psw   => "psw",
			       key   => "/home/user/.ssh/id_rsa", } );

my $maximum_workers = scalar (keys %hosts);
my $maximum_connections = 2 * $maximum_workers;
my $maximum_reconnections = 0;

my %opts = ( workers       => $maximum_workers,
	     connections   => $maximum_connections,
	     reconnections => $maximum_reconnections
    );

my $pssh = Net::OpenSSH::Parallel->new( %opts );

foreach my $label (keys %hosts) {
    $pssh->add_host( $hosts{$label}{host},
		     user              => $hosts{$label}{user},
		     port              => $hosts{$label}{port},
		     password          => $hosts{$label}{psw},
		     key_path          => $hosts{$label}{key},
	);
}

$pssh->push('*', command => 'ls');
$pssh->run;

__END__

$ perl test.pl
Desktop
Documents
.
.
.