Net::OpenSSH to ups appliance

natxo has asked for the wisdom of the Perl Monks concerning the following question:

hi, I would like to get some output from an UPS (http://en.wikipedia.org/wiki/Uninterruptible_power_supply) unit. This thing has a ssh and a web interface. If I login interactively to the unit, this is what I see:

slogin user@ups
Authenticated with partial success.
user@ups's password: 



American Power Conversion               Network Management Card AOS   
+   v3.7.3
(c) Copyright 2009 All Rights Reserved  Smart-UPS & Matrix-UPS APP    
+   v3.7.2
----------------------------------------------------------------------
+---------
Name      : asset                                     Date : 29.08.201
+3
Contact   : sysadmin                                  Time : 12:27:03
Location  : somewhere                                 User : Administr
+ator
Up Time   : 0 Days 4 Hours 9 Minutes                  Stat : P+ N+ A+

Smart-UPS 1500 RM named asset : On Line, No Alarms Present

------- Control Console ----------------------------------------------
+---------

     1- Device Manager
     2- Network
     3- System
     4- Logout

     <ESC>- Main Menu, <ENTER>- Refresh, <CTRL-L>- Event Log
[download]

So this is like a motd when you login. How can I capture this info? I have tried this:

use strict;
use warnings;

use Net::OpenSSH;

my $host = shift;
my $stdin;
my $stdout;
my $stderr;

print $host, "\n";

my $ssh = Net::OpenSSH->new(
    $host,
    user                => "user",
    password            => "password",
    timeout             => 30,
    default_stdin_fh    => $stdin,
    default_stdout_fh   => $stdout,
    default_stderr_fh   => $stderr,
);

$ssh->error and die "Can't ssh to $host: " . $ssh->error;

print "stdin is $stdin\n" if defined $stdin ;
print "stdout is $stdout\n" if defined $stdout;
print "stderr is $stderr\n" if defined $stderr ;
[download]

But I am afraid I am getting nothing. I know I can log in, I see that on the log file, but am a bit confused about getting the info. Any help appreciated.

Comment on Net::OpenSSH to ups appliance Select or Download Code

Replies are listed 'Best First'.
Re: Net::OpenSSH to ups appliance by salva (Canon) on Aug 29, 2013 at 12:18 UTC
The SSH implementation on that device seems crippled. It doesn't perform authentication using the SSH protocol. Instead it asks for the password when a shell is started on some SSH channel. Net::OpenSSH will not handle authenticating against such systems. Though, if all you want is getting the motd, the following code may work: `my $ssh = Net::OpenSSH->new($host, user => $user, timeout => 30); my $motd = $ssh->capture({stdin_data => "$password\n\n4\n", stderr_to_stdout => 1}); print $motd;` [download] Alternatively, just use Expect.	[reply] [d/l]
Re^2: Net::OpenSSH to ups appliance by natxo (Scribe) on Aug 29, 2013 at 13:45 UTC
Thanks for the tip. This is what is working for me now: `my $ssh = Net::OpenSSH->new( $host, user => "user", password => "password", timeout => 30, ); my $motd = $ssh->capture( { stderr_to_stdout => 1, } ); print $motd;` [download] The devices are indeed crippled, and unfortunately we need to resort to this kind of stuff to know when they break.	[reply] [d/l]