Java

SSH Tunnel Thread Activity Log

Demonstrates the tunnel-log properties KeepTunnelLog, TunnelLog, and TunnelLogPath, which record the activity of the SSH tunnel and client-manager threads.

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

Background: This is the counterpart to the accept log, covering the SSH side rather than the listener: the tunnel and client-manager threads that actually move data. As with the accept log, KeepTunnelLog enables the in-memory TunnelLog while TunnelLogPath writes a separate file. Together the two logs let you localize a problem to either the accepting side or the forwarding side.

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Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    //  Demonstrates the SshTunnel tunnel-log properties KeepTunnelLog, TunnelLog, and TunnelLogPath.
    //  
    //  These log the activity of the SSH tunnel and client-manager threads.

    CkSshTunnel tunnel = new CkSshTunnel();

    //  Retain the SSH tunnel-thread activity in memory so it can be read from the TunnelLog property.
    tunnel.put_KeepTunnelLog(true);

    //  Optionally also write the tunnel-thread activity to a file (separate from the in-memory log).
    tunnel.put_TunnelLogPath("qa_output/tunnel.log");

    tunnel.put_DestHostname("db.internal.example.com");
    tunnel.put_DestPort(5432);

    int sshPort = 22;
    success = tunnel.Connect("ssh.example.com",sshPort);
    if (success == false) {
        System.out.println(tunnel.lastErrorText());
        return;
        }

    //  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.
    String password = "mySshPassword";

    success = tunnel.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        System.out.println(tunnel.lastErrorText());
        return;
        }

    int listenPort = 1080;
    success = tunnel.BeginAccepting(listenPort);
    if (success == false) {
        System.out.println(tunnel.lastErrorText());
        return;
        }

    //  ... clients transfer data through the tunnel ...

    //  Read the accumulated in-memory tunnel log.
    System.out.println(tunnel.tunnelLog());

    boolean waitForThreadExit = true;
    success = tunnel.CloseTunnel(waitForThreadExit);
    if (success == false) {
        System.out.println(tunnel.lastErrorText());
        return;
        }
  }
}