I have got this error when i try to connect to my switch !
use Net::OpenSSH;
use warnings;
use Expect;
my $password = 'admin';
my $enable = '';
my $ip = '192.16.25.39';
my $username='user';
my $ssh = Net::OpenSSH->new("$username:$password\#$ip", timeout => 200) ;
$ssh->error and die "unable to connect to remote host: ". $ssh->error;
my $output = $ssh->capture({stdin_data => "enable\n"."admin%\n"."show vlan"."\n"});
if ($output) {print $output . ' ';}
my $line;
print "\n";
# closes the ssh connection
$ssh->close();
I have tried this with the Expect module:
use Net::OpenSSH;
if ($output) {
print $output . ' ';
my $expect = Expect->init($output);
$expect->raw_pty(1);
#$expect->debug(2);
my $debug and $expect->log_stdout(1);
while(<$pty>) {
print "$. $_ "
}
}
which produces this error:
Can't bless non-reference value at /usr/local/share/perl5/Expect.pm line 202 (#1) (F) Only hard references may be blessed. This is how Perl "enforces" encapsulation of objects. See perlobj. Uncaught exception from user code: Can't bless non-reference value at /usr/local/share/perl5/Expect.pm line 202. at /usr/local/share/perl5/Expect.pm line 202. Expect::exp_init("Expect", "\x{d}\x{a}witch>enable\x{d}\x{a}password:\x{d}\x{a}switch#show vlan\x{d}\x{a}\x{d}\x{a}VLA"...) called at b.pl line 19 "
This might be a better approach to your problem. There is a Net::Telnet::Cisco module that simplifies a lot of the interaction with the remote router. Apparently you can first set up an encrypted SSH connection with Net::OpenSSH and then use the filehandle from that connection to start a Net::Telnet::Cisco session.
So I think something like this would be more promising than trying to use Net::OpenSSH directly:
use Net::OpenSSH;
use Net::Telnet::Cisco;
my $password = 'admin';
my $enable = '';
my $ip = '192.16.25.39';
my $username='user';
my $ssh = Net::OpenSSH->new("$username:$password\#$ip", timeout => 200) ;
my ($pty, $pid) = $ssh->open2pty({stderr_to_stdout => 1})
or die "unable to start remote shell: " . $ssh->error;
my $cisco = Net::Telnet::Cisco->new(
-fhopen => $pty,
-telnetmode => 0,
-cmd_remove_mode => 1,
-output_record_separator => "\r");
my #vlan = $cisco->cmd("show vlan");
I am not familiar with the ins and outs of configuring Cisco routers, so you'll have to take it up from here, but this looks to me like a much easier route to get what you need.
Related
Using Perl's Net::Telnet module to retrieve data from upsd.
There is one particular function I'm trying to implement, retrieving the data for a single var.
The problem is only a single line is output, and that line is used to match
Prompt, so it is not output.
Here's raw telnet:
telnet dns1 3493
Trying 192.168.15.1...
Connected to dns1.
Escape character is '^]'.
get var cp1500 ups.test.result
VAR cp1500 ups.test.result "Done and passed"
Connection closed by foreign host.
Here's some code:
#!/usr/bin/perl
use strict;
use warnings;
use Net::Telnet;
my $host = "dns1";
my $model = "cp1500";
my $bvar = "ups.test.result";
my $t = new Net::Telnet (Timeout => 3, Port => 3493, Prompt => "/VAR $model $bvar/");
$t->open($host);
my #ary = $t->cmd("get var $model $bvar");
print #ary,"\n";
This just prints the newline as the array is empty. Prompt is matched else there'd be a timeout error. How can I get that single line of output back for processing in the script?
This is my solution, use Socket instead of Net::Telnet.
#!/usr/bin/perl
use strict;
use warnings;
use Socket;
my $host = 'str003';
my $port = 3493;
my $model = 'cp1350';
my $quer = 'get var';
my $bvar = 'ups.test.result';
my ($sock,$iaddr,$paddr,$send);
$iaddr = inet_aton($host);
$paddr = sockaddr_in($port, $iaddr);
$send = join(' ',$quer,$model,$bvar);
socket($sock, AF_INET, SOCK_STREAM, 6) or die $!;
connect($sock , $paddr) or die "connect failed : $!";
send($sock , "$send\nlogout\n" , 0);
while (my $line = <$sock>)
{
if ($line =~ /^VAR/) {
print "$line\n";
}
}
close($sock);
This is the one where one line of data is returned:
VAR cp1350 ups.test.result "Done and passed"
I have a script, which does SSH to the server and execute some command (In this script, for demonstration I am running Perl print statement with Hello message).
Here is my script:
#!/usr/bin/perl
use strict; use warnings;
use Net::OpenSSH;
$Net::OpenSSH::debug = ~0;
BEGIN {
open my $out, '>', '/tmp/debug.txt' or warn $!;
$Net::OpenSSH::debug_fh = $out;
$Net::OpenSSH::debug = -1;
}
my #hosts = ("ipaddress1","ipaddress2");
my $ssh;
my $command = "perl -e 'print \"Hello..\"'";
foreach my $n (#hosts) {
#Here if connection to the host($n) fails, is it possible to retry again
$ssh = Connect($n, "user", "passwd");
$ssh->capture($command);
print "Done execution in Host: $n\n";
}
undef $ssh;
print "**End**\n";
sub Connect {
my ( $host, $user, $passwd ) = #_;
my $ssh = Net::OpenSSH->new($host, user=>$user, password=>$passwd);
$ssh->error and die "Couldn't establish SSH connection: " . $ssh->error;
return $ssh;
}
Whenever I execute this script, sometimes it successfully prints below message:
Done execution in Host: ipaddress1
Done execution in Host: ipaddress2
**End**
But sometimes cannot do ssh to host (either ipaddress1 or ipaddress2) and gives following message:
Couldn't establish SSH connection: unable to establish master SSH connection: master process exited unexpectedly at script.pl ....
Its being get died in Connect subroutine (cause I couldn't trace, opened question here).
So, is there any way if I cannot connect(ssh) to the host, retry can be done after certain period of time (for n number times) instead of printing error message and make the script die?
OpenSSH provides a nice interface for errors. I'd start by looking at the examples on the cpan page. Try the following
foreach my $n (#hosts) {
#Here if connection to the host($n) fails, is it possible to retry again
$ssh = Connect($n, "user", "passwd", 3);
$ssh->capture($command);
print "Done execution in Host: $n\n";
}
undef $ssh;
print "**End**\n";
sub Connect {
my ( $host, $user, $passwd , $retry_limit ) = #_;
my $timeout = 10;
my $con;
while ( $retry_limit-- > 0 )
{
$con = Net::OpenSSH->new($host,
user=>$user,
password=>$passwd,
timeout=> $timeout,
);
last unless $con->error();
}
die "unable to connect ".$con->error() if retry_limit <0;
return $con;
}
I have built a script which should get a file from remote machine to local machine.
#!/usr/bin/perl
use strict;
use warnings;
use Net::OpenSSH;
use Data::Dumper;
my $local_dir = "/LOCAL/DIR/LOCATION/"
print "[LOCAL DIR]-> $local_dir\n";
my $remote_dir = "/REMOTE/DIR/LOCATION/";
print "[REMOTE DIR]-> $remote_dir\n";
my ($host, $user, $password) = ("remote.machine.ip.address", "userid", "password");
my $ssh = Net::OpenSSH->new($host,
user => $user,
password => $passwd,
master_opts => [-o => "StrictHostKeyChecking=no"]
);
$ssh->error and die "Couldn't establish SSH connection: ". $ssh->error;
my #file = $ssh->capture("cd $remote_dir && ls -1tr | grep Report | tail -1");
print "[FILE]:\n".Dumper(\#file);
$ssh->scp_get({glob => 1}, "$remote_dir$file[0]", $local_dir)
or die "scp failed: " . $ssh->error;
undef $ssh;
In the above code its able to print the Dumper value for #file but unable to get the file in local system.
Here is the error it throws at the end:
[FILE]:
$VAR1 = [
'Report_Managable_20200705.csv
'
];
scp: /REMOTE/DIR/LOCATION/Report_Managable_20200705.csv
protocol error: expected control record
scp failed: scp failed: child exited with code 1 at file_get_test.pl line 22.
Can anybody help me to fix this issue. TIA.
The list returned by $ssh->capture() has new lines at the end of each item. Try use chomp #file to remove the newlines.
#!/usr/bin/perl
use Net::SSH::Expect;
use warnings;
use strict;
#my($stdout, $stderr, $exit) = $ssh->cmd("ls -l /home/$usr")
# Making an ssh connection with user-password authentication
# 1) construct the object
my $ssh = Net::SSH::Expect->new (
host => "host",
password=> 'pwd',
user => 'user',
raw_pty => 1
#Expect=>log_file("finally.txt")
);
# 2) logon to the SSH server using those credentials.
# test the login output to make sure we had success
my $login_output = $ssh->login();
if ($login_output !~ /Welcome/) {
die "Login has failed. Login output was $login_output";
}
# disable terminal translations and echo on the SSH server
# executing on the server the stty command:
$ssh->exec("stty raw -echo");
my $stdout = $ssh->send(chr(13));
my $stdout2 = $ssh->send("SDT-FI");
my $stdout3 = $ssh->send("ENG");
my $stdout4 = $ssh->send('SORT FI-WIP "84144"');
my $stdout5 = $ssh->send(chr(13));
my $stdout6 = $ssh->send("OFF");
my $stdout7 = $ssh->send(chr(13));
print($stdout3);
#$expect->log_file("adp-n.txt");
#y $line;
# returns the next line, removing it from the input stream:
# while ( defined ($line = $ssh->read_all()) ) {
# print $line . "\n";
#}
So i am trying to print $stdout3 so i can get information about the output
but i keep getting " use of uninitialized value $stdout3 in print at connnn3.pl line 50"
is there something in my code wrong?
how can i fix this?
UPDATE, SOLVED!
The reason why it was returning "use of uninitialized value" was because the function
send()
Is void, so instead i used
exec()
And that solved it
From the documentation of Net::SSH::Expect:
void send($string) - sends $string to the SSH server, returns nothing
Thus, send obviously returns nothing (void) and that's why you get this warning when trying to print the (non-existing) return value of send. If you want to get data back from the server use peek, eat, read_all or similar as documented.
I am using expect in perl to get interface information from my router. When I run the command on the remote router its missing about 10-15 lines that should be there. Not sure why its stopping, any ideas?
#!/usr/bin/perl -w
#use strict;
use warnings;
use Net::SSH::Expect;
my $ssh = Net::SSH::Expect->new (
host => "10.10.10.10",
user => 'user',
password => 'pass'
);
my $login_output = $ssh->login();
if ($login_output !~ /router#/) {
die "Login has failed. Login output was $login_output";
}
#$ssh->run_ssh() or die "SSH process couldn't start: $!";
$ssh->send("show int g2/1");
my $line;
while (defined ($line = $ssh->read_line()) ) {
print $line."\n";
}
Net::SSH::Expect is not reliable. Use other module as Net::OpenSSH, Net::SSH2, Net::SSH::Any or just Expect
use Net::OpenSSH;
my $ssh = Net::OpenSSH->new("10.10.10.10",
user => 'user',
password => 'pass',
timeout => 60 );
my $output = $ssh->capture('show int g2/1');
# or for some non-conforming SSH server implementations rather
# common in network equipment you will have to do...
my $output = $ssh->capture({stdin_data => "show int g2/1\n"});
$ssh->error and die "unable to run remote command: " . $ssh->error;
I suspect since you are dealing with a router, you want to enable raw_pty => 1 like the Net::SSH::Expect documentation suggests. Also, it might be easier for you to use the ->exec calls instead of the ->send + read_line.
For debugging further, pass in the log_stdout to the Net::SSH::Expect constructor and see if you can detect anything awry happening. Why did you comment out 'use strict'? Always 'use strict' and 'use warnings'