SSH Parallel Remote Commands on Multiple Servers

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Demonstrates running the same command on several servers simultaneously. It is simply a matter of using one Ssh object per server, starting the command on each with QuickCmdSend, and then polling each connection with QuickCmdCheck until all have finished.

var
success: Boolean;
ssh1: HCkSsh;
ssh2: HCkSsh;
ssh3: HCkSsh;
port: Integer;
password: PWideChar;
cmd: PWideChar;
channel1: Integer;
channel2: Integer;
channel3: Integer;
pollTimeoutMs: Integer;
numFinished: Integer;
finished1: Boolean;
finished2: Boolean;
finished3: Boolean;
ch1: Integer;
out1: PWideChar;
ch2: Integer;
out2: PWideChar;
ch3: Integer;
out3: PWideChar;

begin
success := False;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  Demonstrates running the same command on several servers simultaneously.  It is simply a
//  matter of using one Ssh object per server.

ssh1 := CkSsh_Create();
ssh2 := CkSsh_Create();
ssh3 := CkSsh_Create();

port := 22;

//  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 := CkSsh_Connect(ssh1,'ssh-server1.example.com',port);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh1));
    Exit;
  end;
success := CkSsh_AuthenticatePw(ssh1,'mySshLogin',password);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh1));
    Exit;
  end;

success := CkSsh_Connect(ssh2,'ssh-server2.example.com',port);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh2));
    Exit;
  end;
success := CkSsh_AuthenticatePw(ssh2,'mySshLogin',password);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh2));
    Exit;
  end;

success := CkSsh_Connect(ssh3,'ssh-server3.example.com',port);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh3));
    Exit;
  end;
success := CkSsh_AuthenticatePw(ssh3,'mySshLogin',password);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh3));
    Exit;
  end;

//  This command sleeps for 5 seconds and then prints the system date/time, making the parallel
//  execution easy to observe.
cmd := 'sleep 5; date';

//  Start the command on each server.  QuickCmdSend returns immediately.
channel1 := CkSsh_QuickCmdSend(ssh1,cmd);
if (channel1 < 0) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh1));
    Exit;
  end;

channel2 := CkSsh_QuickCmdSend(ssh2,cmd);
if (channel2 < 0) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh2));
    Exit;
  end;

channel3 := CkSsh_QuickCmdSend(ssh3,cmd);
if (channel3 < 0) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh3));
    Exit;
  end;

//  The command is now running on all three servers at once.  Poll each connection until every
//  command has finished.  (Production code would keep the objects in arrays rather than
//  repeating the logic.)
pollTimeoutMs := 50;
numFinished := 0;
finished1 := False;
finished2 := False;
finished3 := False;

while numFinished < 3 do
  begin
    if (not finished1) then
      begin
        ch1 := CkSsh_QuickCmdCheck(ssh1,pollTimeoutMs);
        if (ch1 = -2) then
          begin
            Memo1.Lines.Add(CkSsh__lastErrorText(ssh1));
            Exit;
          end;
        if (ch1 >= 0) then
          begin
            Memo1.Lines.Add('---- ssh1 channel ' + IntToStr(ch1) + ' finished ----');
            out1 := CkSsh__getReceivedText(ssh1,ch1,'utf-8');
            if (CkSsh_getLastMethodSuccess(ssh1) = False) then
              begin
                Memo1.Lines.Add(CkSsh__lastErrorText(ssh1));
                Exit;
              end;
            Memo1.Lines.Add(out1);
            finished1 := True;
            numFinished := numFinished + 1;
          end;
      end;

    if (not finished2) then
      begin
        ch2 := CkSsh_QuickCmdCheck(ssh2,pollTimeoutMs);
        if (ch2 = -2) then
          begin
            Memo1.Lines.Add(CkSsh__lastErrorText(ssh2));
            Exit;
          end;
        if (ch2 >= 0) then
          begin
            Memo1.Lines.Add('---- ssh2 channel ' + IntToStr(ch2) + ' finished ----');
            out2 := CkSsh__getReceivedText(ssh2,ch2,'utf-8');
            if (CkSsh_getLastMethodSuccess(ssh2) = False) then
              begin
                Memo1.Lines.Add(CkSsh__lastErrorText(ssh2));
                Exit;
              end;
            Memo1.Lines.Add(out2);
            finished2 := True;
            numFinished := numFinished + 1;
          end;
      end;

    if (not finished3) then
      begin
        ch3 := CkSsh_QuickCmdCheck(ssh3,pollTimeoutMs);
        if (ch3 = -2) then
          begin
            Memo1.Lines.Add(CkSsh__lastErrorText(ssh3));
            Exit;
          end;
        if (ch3 >= 0) then
          begin
            Memo1.Lines.Add('---- ssh3 channel ' + IntToStr(ch3) + ' finished ----');
            out3 := CkSsh__getReceivedText(ssh3,ch3,'utf-8');
            if (CkSsh_getLastMethodSuccess(ssh3) = False) then
              begin
                Memo1.Lines.Add(CkSsh__lastErrorText(ssh3));
                Exit;
              end;
            Memo1.Lines.Add(out3);
            finished3 := True;
            numFinished := numFinished + 1;
          end;
      end;
  end;

CkSsh_Disconnect(ssh1);
CkSsh_Disconnect(ssh2);
CkSsh_Disconnect(ssh3);

CkSsh_Dispose(ssh1);
CkSsh_Dispose(ssh2);
CkSsh_Dispose(ssh3);