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.

bool 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.

Chilkat.Ssh ssh1 = new Chilkat.Ssh();
Chilkat.Ssh ssh2 = new Chilkat.Ssh();
Chilkat.Ssh ssh3 = new Chilkat.Ssh();

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) {
    Debug.WriteLine(ssh1.LastErrorText);
    return;
}

success = ssh1.AuthenticatePw("mySshLogin",password);
if (success == false) {
    Debug.WriteLine(ssh1.LastErrorText);
    return;
}

success = ssh2.Connect("ssh-server2.example.com",port);
if (success == false) {
    Debug.WriteLine(ssh2.LastErrorText);
    return;
}

success = ssh2.AuthenticatePw("mySshLogin",password);
if (success == false) {
    Debug.WriteLine(ssh2.LastErrorText);
    return;
}

success = ssh3.Connect("ssh-server3.example.com",port);
if (success == false) {
    Debug.WriteLine(ssh3.LastErrorText);
    return;
}

success = ssh3.AuthenticatePw("mySshLogin",password);
if (success == false) {
    Debug.WriteLine(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) {
    Debug.WriteLine(ssh1.LastErrorText);
    return;
}

int channel2 = ssh2.QuickCmdSend(cmd);
if (channel2 < 0) {
    Debug.WriteLine(ssh2.LastErrorText);
    return;
}

int channel3 = ssh3.QuickCmdSend(cmd);
if (channel3 < 0) {
    Debug.WriteLine(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;
bool finished1 = false;
bool finished2 = false;
bool finished3 = false;

while (numFinished < 3) {
    if (!finished1) {
        int ch1 = ssh1.QuickCmdCheck(pollTimeoutMs);
        if (ch1 == -2) {
            Debug.WriteLine(ssh1.LastErrorText);
            return;
        }

        if (ch1 >= 0) {
            Debug.WriteLine("---- ssh1 channel " + Convert.ToString(ch1) + " finished ----");
            string out1 = ssh1.GetReceivedText(ch1,"utf-8");
            if (ssh1.LastMethodSuccess == false) {
                Debug.WriteLine(ssh1.LastErrorText);
                return;
            }

            Debug.WriteLine(out1);
            finished1 = true;
            numFinished = numFinished + 1;
        }

    }

    if (!finished2) {
        int ch2 = ssh2.QuickCmdCheck(pollTimeoutMs);
        if (ch2 == -2) {
            Debug.WriteLine(ssh2.LastErrorText);
            return;
        }

        if (ch2 >= 0) {
            Debug.WriteLine("---- ssh2 channel " + Convert.ToString(ch2) + " finished ----");
            string out2 = ssh2.GetReceivedText(ch2,"utf-8");
            if (ssh2.LastMethodSuccess == false) {
                Debug.WriteLine(ssh2.LastErrorText);
                return;
            }

            Debug.WriteLine(out2);
            finished2 = true;
            numFinished = numFinished + 1;
        }

    }

    if (!finished3) {
        int ch3 = ssh3.QuickCmdCheck(pollTimeoutMs);
        if (ch3 == -2) {
            Debug.WriteLine(ssh3.LastErrorText);
            return;
        }

        if (ch3 >= 0) {
            Debug.WriteLine("---- ssh3 channel " + Convert.ToString(ch3) + " finished ----");
            string out3 = ssh3.GetReceivedText(ch3,"utf-8");
            if (ssh3.LastMethodSuccess == false) {
                Debug.WriteLine(ssh3.LastErrorText);
                return;
            }

            Debug.WriteLine(out3);
            finished3 = true;
            numFinished = numFinished + 1;
        }

    }

}

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