$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/bob/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/bob/.ssh/id_rsa.
Your public key has been saved in /home/bob/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:LCWI8Wrw14m0Cxz1P+TqmL7Nn+mY19fWETCfjYK87VY bob@bob-ThinkPad-SL510
The key's randomart image is:
+---[RSA 2048]----+
|  . .   .        |
|   = o o     o   |
|. o + o +. .  +.o|
| + + + B .o . .+.|
|  * + = S  o .  .|
| . o = .  . . E. |
|    + .  . . o ..|
|   . o o.o. + o .|
|    o.=+=  o .   |
+----[SHA256]-----+
$ 
##</code><code>##

values are home349337426.1and1-data.host 
The authenticity of host 'home349337426.1and1-data.host' can't be established.
Key fingerprint is SHA1:6bfe32c8859a967c8ed6cebdd5c48b72edff71c7.
Are you sure you want to continue connecting (yes/no)? y
mkdir is not a valid Net::SSH2 macro at ssh4.pl line 31.
$ 

$ 

##</code><code>##

#!/usr/bin/perl -w
use strict;
use Net::SSH2 qw(LIBSSH2_CHANNEL_EXTENDED_DATA_MERGE
                        LIBSSH2_CHANNEL_FLUSH_ALL
                        LIBSSH2_HOSTKEY_POLICY_ASK);

use 5.010;
use lib "template_stuff";
use config2;

# none of this makes any sense until you run
# ssh-keygen -t rsa

my $sub_hash = "my_sftp";
my $domain = $config{$sub_hash}->{'domain'};
my $username = $config{$sub_hash}->{'username'};

say "values are $domain";
my $pass = "ringo";
my $ssh2 = Net::SSH2->new( debug => 1 ); 
$ssh2->trace(-1);
$ssh2->timeout(5000);

$ssh2->connect($domain) or $ssh2->die_with_error;
$ssh2->check_hostkey(LIBSSH2_HOSTKEY_POLICY_ASK);

$ssh2->auth_publickey($username,
                 '/home/bob/.ssh/id_rsa.pub',
                   '/home/bob/.ssh/id_rsa',
                $pass );

my $success = $ssh2->mkdir("perlmonks");
say "success is $success";
return 0;

__END__