(Ruby) SSH Parallel Remote Commands on Multiple Servers

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Shows how to execute a command in parallel on multiple servers.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

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

# Executing a command on multiple servers simultaneously is straightforward.
# It's just a matter of using one SSH object per server..
ssh1 = Chilkat::CkSsh.new()
ssh2 = Chilkat::CkSsh.new()
ssh3 = Chilkat::CkSsh.new()

port = 22
success = ssh1.Connect("ssh-server1.com",port)
if (success != true)
    print ssh1.lastErrorText() + "\n";
    exit
end

# Authenticate using login/password:
success = ssh1.AuthenticatePw("sshLogin1","sshPassword1")
if (success != true)
    print ssh1.lastErrorText() + "\n";
    exit
end

# Connect and authenticate with 2 more servers.
# For brevity, the success/failure won't be checked...
success = ssh2.Connect("ssh-server2.com",port)
success = ssh2.AuthenticatePw("sshLogin2","sshPassword2")
success = ssh3.Connect("ssh-server3.com",port)
success = ssh3.AuthenticatePw("sshLogin3","sshPassword3")

# Note: If we wanted, we could've used ConnectAsync and AuthenticatePwAsync
# to do the connecting and authenticating in parallel...

# The command to be run on each SSH server will sleep for 5 seconds,
# and then show the current system date/time.
cmd = "sleep 5; date"

# Start each command
ssh1Channel = ssh1.QuickCmdSend(cmd)
if (ssh1Channel < 0)
    print ssh1.lastErrorText() + "\n";
    exit
end

# For brevity, we're not checking the return values here:
ssh2Channel = ssh2.QuickCmdSend(cmd)
ssh3Channel = ssh3.QuickCmdSend(cmd)

# OK, at this point the command is running simultaneously on each server.

# Now collect the results of each command.
pollTimeoutMs = 50
numFinished = 0

# Note: You would rewrite this code to use arrays.
ssh1Finished = false
ssh2Finished = false
ssh3Finished = false
while numFinished < 3
    # Check to see if anything has finished.
    # QuickCmdCheck returns -1 if there are no errors and nothing else finished
    # QuickCmdCheck returns -2 if there was an error (such as a lost connection)
    # QuickCmdCheck returns a channel number if a channel finished.
    if (ssh1Finished != true)
        channel = ssh1.QuickCmdCheck(pollTimeoutMs)
        if (channel == -2)
            print ssh1.lastErrorText() + "\n";
            exit
        end

        if (channel == ssh1Channel)
            print "---- ssh1 channel " + channel.to_s() + " finished ----" + "\n";
            print ssh1.getReceivedText(channel,"ansi") + "\n";
            numFinished = numFinished + 1
            ssh1Finished = true
        end

    end

    if (ssh2Finished != true)
        channel = ssh2.QuickCmdCheck(pollTimeoutMs)
        if (channel == -2)
            print ssh2.lastErrorText() + "\n";
            exit
        end

        if (channel == ssh2Channel)
            print "---- ssh2 channel " + channel.to_s() + " finished ----" + "\n";
            print ssh2.getReceivedText(channel,"ansi") + "\n";
            numFinished = numFinished + 1
            ssh2Finished = true
        end

    end

    if (ssh3Finished != true)
        channel = ssh3.QuickCmdCheck(pollTimeoutMs)
        if (channel == -2)
            print ssh3.lastErrorText() + "\n";
            exit
        end

        if (channel == ssh3Channel)
            print "---- ssh3 channel " + channel.to_s() + " finished ----" + "\n";
            print ssh3.getReceivedText(channel,"ansi") + "\n";
            numFinished = numFinished + 1
            ssh3Finished = true
        end

    end

end

# --------------
# Sample output:

# 	---- ssh2 channel 101 finished ----
# 	Fri Dec 23 00:25:48 UTC 2016
# 
# 	---- ssh3 channel 102 finished ----
# 	Thu Dec 22 18:25:12 CST 2016
# 
# 	---- ssh1 channel 100 finished ----
# 	Thu Dec 22 18:25:48 CST 2016