Pascal (Lazarus/Delphi)

SSH Tunnel Listener Activity Log

Demonstrates the listener-log properties KeepAcceptLog, AcceptLog, and AcceptLogPath, which record the activity of the background listener thread started by BeginAccepting.

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

Background: Because the listener runs on a background thread, an activity log is often the only practical way to see what it is doing — which connections it accepted and when. KeepAcceptLog must be enabled for the in-memory AcceptLog to be populated; AcceptLogPath is an independent file-based log that persists across the run. This log covers the listener specifically, as distinct from the TunnelLog that records the SSH tunnel threads.

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Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.SshTunnel;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  tunnel: TSshTunnel;
  sshPort: Integer;
  password: string;
  listenPort: Integer;
  waitForThreadExit: Boolean;

begin
  success := False;

  //  Demonstrates the SshTunnel listener-log properties KeepAcceptLog, AcceptLog, and AcceptLogPath.
  //  
  //  These log the activity of the background listener thread started by BeginAccepting.

  tunnel := TSshTunnel.Create;

  //  Retain the listener activity log in memory so it can be read from the AcceptLog property.
  tunnel.KeepAcceptLog := True;

  //  Optionally also write the listener activity to a file (separate from the in-memory log).
  tunnel.AcceptLogPath := 'qa_output/accept.log';

  tunnel.DestHostname := 'db.internal.example.com';
  tunnel.DestPort := 5432;

  sshPort := 22;
  success := tunnel.Connect('ssh.example.com',sshPort);
  if (success = False) then
    begin
      WriteLn(tunnel.LastErrorText);
      Exit;
    end;

  //  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.
  password := 'mySshPassword';

  success := tunnel.AuthenticatePw('mySshLogin',password);
  if (success = False) then
    begin
      WriteLn(tunnel.LastErrorText);
      Exit;
    end;

  listenPort := 1080;
  success := tunnel.BeginAccepting(listenPort);
  if (success = False) then
    begin
      WriteLn(tunnel.LastErrorText);
      Exit;
    end;

  //  ... the listener accepts connections for a while ...

  //  Read the accumulated in-memory listener log.
  WriteLn(tunnel.AcceptLog);

  waitForThreadExit := True;
  success := tunnel.CloseTunnel(waitForThreadExit);
  if (success = False) then
    begin
      WriteLn(tunnel.LastErrorText);
      Exit;
    end;


  tunnel.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.