Re^2: Net::SSH::Perl doesn't execute commands

[bluethundr]

in reply to Re: Net::SSH::Perl doesn't execute commands
in thread Net::SSH::Perl doesn't execute commands

Ok then! Thanks for the very valuable input!

Ok, so I am able to issue commands to the load balancer software (which is a proprietary software layer sitting on top of a BSD core) via ssh and this is what I get:

[bluethundr@cc90-45:~ ] #:ssh bluethundr@10.50.0.1 show lb vserver gl-
+www
Password: 
 Done
    gl-www (0.0.0.0:0) - HTTP    Type: ADDRESS 
    State: UP
    Effective State: UP  ARP:DISABLED
    Client Idle Timeout: 180 sec
    Down state flush: ENABLED
    Port Rewrite : DISABLED
    Configured Method: ROUNDROBIN
    Mode: IP
    Persistence: NONE
    Redirect URL: http://pi.glcdn.us/DowntimeGeneric/gl_downtime.html
    Vserver IP and Port insertion: OFF 

1) cc61-35-http (10.50.35.61: 80) - HTTP State: UP    Weight: 1
2) cc61-44-http (10.50.44.61: 80) - HTTP State: UP    Weight: 1
 Done

So something like this would be the desired output of my little script.

But when I run my script the output would indicate that it's not finding the netscaler commands:

**********LB VSERVERS**********




show lb vserver default-router
Can't exec "show": No such file or directory at ./vservers.pl line 23,
+ <LBVSERVERS> line 1.
Out =  Done
ERROR: No such command
, Error = ERROR: No such command, Exit = 64
Ready for next lb vserver? (y/n): y
show lb vserver gl-www
Can't exec "show": No such file or directory at ./vservers.pl line 23,
+ <LBVSERVERS> line 2.
Out =  Done
ERROR: No such command
, Error = ERROR: No such command, Exit = 64
Ready for next lb vserver? (y/n): y
show lb vserver c9-qa-bp-http
Can't exec "show": No such file or directory at ./vservers.pl line 23,
+ <LBVSERVERS> line 3.
Out =  Done
ERROR: No such command
, Error = ERROR: No such command, Exit = 64
Ready for next lb vserver? (y/n): 

And when I execute a unix shell and do a find on the "show" command it turns up nothing, nada:

root@ns# find / -name show -print
root@ns# 

So my question would be, why does plain old ssh find the netscaler commands when I issue them on the command line, but Net::SSH::Perl does not find them when issued from my script? Also it should be noted that I changed the quote (") marks to backticks (`) in the Net::SSH::Perl commands.

i..e.
was
$ssh->cmd("show lb vserver $csvserver");
changed to

$ssh->cmd(`show lb vserver $csvserver`);

Right now I only have output for the latter and not the former. I can get you the other input (with the quotes) if you feel it's important. Rather late, and retiring right now and picking this up again tomorrow. Thanks for your help!

[rjt]

        $ssh->cmd(`show lb vserver $csvserver`);

That is almost certainly not what you want to do. Your qx// example will run your "show lb ..." command on the local machine and attempt to run the output of that on the remote machine.

It sounds like the root issue of your problem is the "show" command. I would log on to the BSD machine and run "which show" for starters--it may be an alias, or, it might be a builtin of a particular shell on the system that doesn't happen to be the same as the shell for the "bluethundr" user you're logging in with with Net::SSH::Perl.

That being said, diagnostics are everything. I would also debug Net::SSH::Perl as well, by substituting a well-known command in place of "show". I typically start with something like this:

#$ssh->cmd("show lb vserver $csvserver");
my ($out, $err, $exit) = $ssh->cmd("echo show lb vserver $csvserver");
+ # DEBUG
warn "out = '$out', err = '$err', exit = $exit\n";

Which SSH protocol version are you using? You should be using v2. v1 does not support multiple commands per session.

[Khen1950fx]

You haven't given a valid command yet.

$ssh->cmd("show 1b vserver $csvserver");

That's not a command that ssh will recognize.

$ssh->cmd("ls /path/to/csvserver");

That would be a valid command because it's a "system command". I've noticed that a lot of programmers that are new to ssh make the same mistake. I would split the script in to two scripts. The first part would ssh the second part; hence, $ssh->cmd("perl showthis.pl"); would work.

Update: Here's the first part:

#!/usr/bin/perl

use strict;
use Net::SSH::Perl;

my $host = 'localhost';
my $user = 'username';
my $pass = 'password';
my $cmd  = 'perl /path/to/showthis.pl';

my $ssh = Net::SSH::Perl->new(
          $host, 
          protocol => '2',
          debug    => 1,
);
$ssh->login( $user, $pass );

my ( $stdout, $stderr, $exit ) = $ssh->cmd($cmd);
print "$stdout\n";

Update: Here's showthis.pl

#!/usr/bin/perl

use strict;
use warnings;

my $dir = "$ENV{HOME}/data";
open LBVSERVERS, '<', "$dir/lb-vserver"
  or die "Couldn't open file: $!";
open CSVSERVERS, '<', "$dir/cs-vserver"
  or die "Couldn't open file: $!";

print "\n\n\n\n\n**********LB VSERVERS**********\n\n\n\n\n";
while ( my $line = <DIR> ) {
    chomp $line;
    my ( $number, $dir ) = split( /\s+/, $line );
    print "show lb vserver $lbvserver\n";
    print "Ready for next lb vserver? (y/n): ";
    chomp( my $ans = <STDIN> );
    if ( $ans =~ /y|Y/ ) {
        next;
    }
    else {
        last;
    }
}

print "\n\n\n\n\n**********CS VSERVERS**********\n\n\n\n\n";
while ( my $line = <DIR> ) {
    chomp $line;
    my ( $number, $dir ) = split( /\s+/, $line );
    print "show lb vserver $csvserver\n";
    print "Ready for next lb vserver? (y/n): ";
    chomp( my $ans = <STDIN> );
    if ( $ans =~ /y|Y/ ) {
        next;
    }
    else {
        last;
    }
}
print "\n\n\nEnd of line.\n\n\n";

close LBVSERVERS;
close CSVSERVERS;

[bluethundr]

This is a really nice, clean version of the script. Excellent work!

Well I have to admit that I'm really puzzled at this point! Because I cannot find "show" nowhere on this system. It only works if you 1) ssh into the box and operate within the proprietary netscaler environment or 2) if you issue the commands remotely via ssh.

If I execute a "shell" command within the netscaler software to get to a unix shell, this is the result of my best efforts to find the command called "show".



root@ns# find / -name "show" -print
root@ns# show
-bash: show: command not found
root@ns# echo $PATH 
/netscaler:/bin:/sbin:/usr/bin:/usr/sbin:/usr/libexec:/usr/local/bin:/
+usr/local/sbin:.
root@ns# grep -ri show $PATH
grep: /netscaler:/bin:/sbin:/usr/bin:/usr/sbin:/usr/libexec:/usr/local
+/bin:/usr/local/sbin:.: No such file or directory
root@ns# 



What gives? I'm starting to feel like there is some voodoo going on with this box that I don't completely grok! Do I have to somehow invoke the netscaler shell first,before I do anything else?

This is the contents of a directory called "/netscaler" that has a bunch of commands and scripts in it, that I can't seem to make heads or tails of. Most of them are binaries (not scripts) so I can't even "less" them to see what they contain. weird!

root@ns# ls
CITRIX            nscachemgr        nssavecore.sh
aaa_inform_kern        nscgdb            nssh
api            nscli            nssslgen
aslearn            nsconf            nsstart.sh
aslearn.conf        nsconfig        nsstartpe.sh
bgpd            nsconfigaudit        nsstop.sh
filterwsdl        nsconfmig        nssync
htmlinjection        nsconmsg        nssync.sh
icsearch.sh        nscrlrefresh        nstcpdump.sh
icstats            nsdiskspace.sh        nstrace.sh
imi            nsdme            nstune
imish            nsdrevent        nsumon.sh
install.pl        nsdynrouting        nsumond
lmgrd            nsfsyncd        nsvpnd
lmstat            nsgslbconf        nswsrun
lmutil            nsif            ospfd
lmver            nslcd            pitboss
man            nslcdinit.sh        portal
migrate_ZebOS.sh    nslog.sh        ripd
netscaler.conf        nsm            rwpol
netscaler.sh        nsmap            samedit
ns_gui            nsnetsvc        showtechsupport.pl
nsaaad            nsospf            snmp
nsapimgr        nsp            snmpd
nsaudit            nsproflog.sh        vpnsetup
nsauth_httpd        nsprofmon        vtysh
nsauthd            nsreadfile
nsbgp            nsrip