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.

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;

    //  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.

    CkSsh ssh1 = new CkSsh();
    CkSsh ssh2 = new CkSsh();
    CkSsh ssh3 = new CkSsh();

    int 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.
    String password = "mySshPassword";

    success = ssh1.Connect("ssh-server1.example.com",port);
    if (success == false) {
        System.out.println(ssh1.lastErrorText());
        return;
        }

    success = ssh1.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        System.out.println(ssh1.lastErrorText());
        return;
        }

    success = ssh2.Connect("ssh-server2.example.com",port);
    if (success == false) {
        System.out.println(ssh2.lastErrorText());
        return;
        }

    success = ssh2.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        System.out.println(ssh2.lastErrorText());
        return;
        }

    success = ssh3.Connect("ssh-server3.example.com",port);
    if (success == false) {
        System.out.println(ssh3.lastErrorText());
        return;
        }

    success = ssh3.AuthenticatePw("mySshLogin",password);
    if (success == false) {
        System.out.println(ssh3.lastErrorText());
        return;
        }

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

    //  Start the command on each server.  QuickCmdSend returns immediately.
    int channel1 = ssh1.QuickCmdSend(cmd);
    if (channel1 < 0) {
        System.out.println(ssh1.lastErrorText());
        return;
        }

    int channel2 = ssh2.QuickCmdSend(cmd);
    if (channel2 < 0) {
        System.out.println(ssh2.lastErrorText());
        return;
        }

    int channel3 = ssh3.QuickCmdSend(cmd);
    if (channel3 < 0) {
        System.out.println(ssh3.lastErrorText());
        return;
        }

    //  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.)
    int pollTimeoutMs = 50;
    int numFinished = 0;
    boolean finished1 = false;
    boolean finished2 = false;
    boolean finished3 = false;

    while (numFinished < 3) {
        if (!finished1) {
            int ch1 = ssh1.QuickCmdCheck(pollTimeoutMs);
            if (ch1 == -2) {
                System.out.println(ssh1.lastErrorText());
                return;
                }

            if (ch1 >= 0) {
                System.out.println("---- ssh1 channel " + ch1 + " finished ----");
                String out1 = ssh1.getReceivedText(ch1,"utf-8");
                if (ssh1.get_LastMethodSuccess() == false) {
                    System.out.println(ssh1.lastErrorText());
                    return;
                    }

                System.out.println(out1);
                finished1 = true;
                numFinished = numFinished+1;
                }

            }

        if (!finished2) {
            int ch2 = ssh2.QuickCmdCheck(pollTimeoutMs);
            if (ch2 == -2) {
                System.out.println(ssh2.lastErrorText());
                return;
                }

            if (ch2 >= 0) {
                System.out.println("---- ssh2 channel " + ch2 + " finished ----");
                String out2 = ssh2.getReceivedText(ch2,"utf-8");
                if (ssh2.get_LastMethodSuccess() == false) {
                    System.out.println(ssh2.lastErrorText());
                    return;
                    }

                System.out.println(out2);
                finished2 = true;
                numFinished = numFinished+1;
                }

            }

        if (!finished3) {
            int ch3 = ssh3.QuickCmdCheck(pollTimeoutMs);
            if (ch3 == -2) {
                System.out.println(ssh3.lastErrorText());
                return;
                }

            if (ch3 >= 0) {
                System.out.println("---- ssh3 channel " + ch3 + " finished ----");
                String out3 = ssh3.getReceivedText(ch3,"utf-8");
                if (ssh3.get_LastMethodSuccess() == false) {
                    System.out.println(ssh3.lastErrorText());
                    return;
                    }

                System.out.println(out3);
                finished3 = true;
                numFinished = numFinished+1;
                }

            }

        }

    ssh1.Disconnect();
    ssh2.Disconnect();
    ssh3.Disconnect();
  }
}