Net::SSH2 Command Timeout Before Completion

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

Following the many examples out there, I came up with the following basic code which works 90% of the time. The only time I have a problem is with long-running processes. For example, restarting the syslog service on RHEL 5 doesn't complete before the script closes the channel and exits.

#!/usr/bin/perl
use strict;
use warnings;
use Net::SSH2;
use Term::ReadKey;

my $host = '192.168.123.5';
my $user = 'root';
my $pass = getpass();
my $ssh = Net::SSH2->new();

$ssh->connect($host) or die $!;
$ssh->auth_password($user,$pass) or die $!;
my $chan = $ssh->channel();
$chan->shell();
print $chan "/sbin/service syslog restart";
print "$_" while <$chan>;
$chan->close;
$ssh->disconnect;
[download]

I tried setting "blocking" to "0" as suggested in several locations. This didn't work. I set "poll(10000)" and it appears to have ignored the timeout wait. I set debug on ssh and here is what I get (note no output):

$ ./ssh.pl 
Password: 
libssh2_channel_open_ex(ss->session, pv_channel_type, len_channel_type
+, window_size, packet_size, ((void *)0) , 0 ) -> 0x1b10be0
Net::SSH2::poll: timeout = 10000, array[0]
Net::SSH2::poll: timeout = 250, array[1]
- [0] = channel
- [0] events 1
- libssh2_poll returned 0
- [0] revents 0
Net::SSH2::Channel::DESTROY
Net::SSH2::DESTROY object 0x1a055a0
[download]

Seeing as I will ultimately be using keys, might it be best if I just drop Net::SSH2 in favor of ssh via system?

Comment on Net::SSH2 Command Timeout Before Completion Select or Download Code

Replies are listed 'Best First'.
Re: Net::SSH2 Command Timeout Before Completion by sierpinski (Chaplain) on Jun 29, 2010 at 17:20 UTC
Take a look at Net::SSH::Expect... I use it quite a lot, and it works really well. It has configurable timeouts for connections, and many other options. Below is an example from one of my scripts: `my $ssh = Net::SSH::Expect->new ( host => "$serverlist[$host]", user => "$user", raw_pty => 1, restart_timeout_upon_receive => 1, timeout => 5, ssh_option => " -x -o ConnectTimeout=4", log_file=> "/tmp/$serverlist[$host].log", );` [download] One difference is that this module expects to use an SSH key instead of an interactive password. I don't know if that's an issue for you or not.	[reply] [d/l]
Re^2: Net::SSH2 Command Timeout Before Completion by taim (Initiate) on Jun 29, 2010 at 23:56 UTC
I will be using a key eventually (I hope). I will give it a bit of a test. Thanks.	[reply]
Re: Net::SSH2 Command Timeout Before Completion by salva (Canon) on Jun 29, 2010 at 18:42 UTC
If you have a recent version of OpenSSH installed on the machine where you want to run the script, try Net::OpenSSH: `use Net::OpenSSH; my $ssh = Net::OpenSSH->new('root@192.168.123.5'); $ssh->error and die "unable to connect to remote host: ". $ssh->error; my $fh = $ssh->pipe_out("/sbin/service", "syslog", "restart") or die "command failed: " . $ssh->error; print while <$fh>; close $fh or die "command failed: $?";` [download]	[reply] [d/l]
Re^2: Net::SSH2 Command Timeout Before Completion by taim (Initiate) on Jun 29, 2010 at 23:57 UTC
Another one I will look at. OpenSSH is my client/server of choice.	[reply]
Re^3: Net::SSH2 Command Timeout Before Completion by sierpinski (Chaplain) on Jun 30, 2010 at 01:52 UTC
Another one I will look at. OpenSSH is my client/server of choice. For what it's worth, Net::SSH::Expect lets you choose what ssh binary to use, so if you have openssh installed separately, it can be told to use that. Not trying to be a fanboy, just letting you know.	[reply]
Re^4: Net::SSH2 Command Timeout Before Completion by taim (Initiate) on Jun 30, 2010 at 15:25 UTC


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