Perl

SSH Tunnel Per-Client Logging and Client Identifier

Demonstrates the ClientLogDir and ClientIdentifier properties. When ClientLogDir is set, a separate log file is created for each tunnel client; ClientIdentifier is the SSH client-identification string sent during the handshake.

Note: The log paths are relative to the application's current working directory. Absolute paths may also be used.

Background: When many clients share one tunnel, a single combined log is hard to follow, so ClientLogDir gives each connection its own file — the fastest way to diagnose one misbehaving client. ClientIdentifier sets the version string the server sees; overriding the default is occasionally needed for compatibility with servers that key behavior off the client identification, or simply to label your application in server logs.

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Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# Demonstrates the SshTunnel per-client logging properties ClientLogDir and ClientIdentifier.

my $tunnel = Chilkat2::SshTunnel->new;

# When ClientLogDir is set, a separate log file is created for each tunnel client in this
# directory, which is useful for troubleshooting individual connections.
$tunnel->ClientLogDir('qa_output/client_logs');

# The SSH client-identification string sent to the SSH server during the handshake.
$tunnel->ClientIdentifier('SSH-2.0-MyTunnelApp_1.0');

$tunnel->DestHostname('db.internal.example.com');
$tunnel->DestPort(5432);

my $sshPort = 22;
my $success = $tunnel->Connect('ssh.example.com', $sshPort);
if (!$success) {
    print $tunnel->LastErrorText, "\n";
    exit;
}

# Normally you would not hard-code the password in source.  You should instead obtain it
# from an interactive prompt, environment variable, or a secrets vault.
my $password = 'mySshPassword';

$success = $tunnel->AuthenticatePw('mySshLogin', $password);
if (!$success) {
    print $tunnel->LastErrorText, "\n";
    exit;
}

my $listenPort = 1080;
$success = $tunnel->BeginAccepting($listenPort);
if (!$success) {
    print $tunnel->LastErrorText, "\n";
    exit;
}

print 'Tunnel running; each client is logged in ', $tunnel->ClientLogDir, "\n";

my $waitForThreadExit = 1;
$success = $tunnel->CloseTunnel($waitForThreadExit);
if (!$success) {
    print $tunnel->LastErrorText, "\n";
    exit;
}