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.

load ./chilkat.dll

set success 0

#  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.

set ssh1 [new_CkSsh]

set ssh2 [new_CkSsh]

set ssh3 [new_CkSsh]

set 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.
set password "mySshPassword"

set success [CkSsh_Connect $ssh1 "ssh-server1.example.com" $port]
if {$success == 0} then {
    puts [CkSsh_lastErrorText $ssh1]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkSsh $ssh3
    exit
}

set success [CkSsh_AuthenticatePw $ssh1 "mySshLogin" $password]
if {$success == 0} then {
    puts [CkSsh_lastErrorText $ssh1]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkSsh $ssh3
    exit
}

set success [CkSsh_Connect $ssh2 "ssh-server2.example.com" $port]
if {$success == 0} then {
    puts [CkSsh_lastErrorText $ssh2]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkSsh $ssh3
    exit
}

set success [CkSsh_AuthenticatePw $ssh2 "mySshLogin" $password]
if {$success == 0} then {
    puts [CkSsh_lastErrorText $ssh2]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkSsh $ssh3
    exit
}

set success [CkSsh_Connect $ssh3 "ssh-server3.example.com" $port]
if {$success == 0} then {
    puts [CkSsh_lastErrorText $ssh3]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkSsh $ssh3
    exit
}

set success [CkSsh_AuthenticatePw $ssh3 "mySshLogin" $password]
if {$success == 0} then {
    puts [CkSsh_lastErrorText $ssh3]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkSsh $ssh3
    exit
}

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

#  Start the command on each server.  QuickCmdSend returns immediately.
set channel1 [CkSsh_QuickCmdSend $ssh1 $cmd]
if {$channel1 < 0} then {
    puts [CkSsh_lastErrorText $ssh1]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkSsh $ssh3
    exit
}

set channel2 [CkSsh_QuickCmdSend $ssh2 $cmd]
if {$channel2 < 0} then {
    puts [CkSsh_lastErrorText $ssh2]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkSsh $ssh3
    exit
}

set channel3 [CkSsh_QuickCmdSend $ssh3 $cmd]
if {$channel3 < 0} then {
    puts [CkSsh_lastErrorText $ssh3]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkSsh $ssh3
    exit
}

#  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.)
set pollTimeoutMs 50
set numFinished 0
set finished1 0
set finished2 0
set finished3 0

while {$numFinished < 3} {
    if {!$finished1} then {
        set ch1 [CkSsh_QuickCmdCheck $ssh1 $pollTimeoutMs]
        if {$ch1 == -2} then {
            puts [CkSsh_lastErrorText $ssh1]
            delete_CkSsh $ssh1
            delete_CkSsh $ssh2
            delete_CkSsh $ssh3
            exit
        }

        if {$ch1 >= 0} then {
            puts "---- ssh1 channel $ch1 finished ----"
            set out1 [CkSsh_getReceivedText $ssh1 $ch1 "utf-8"]
            if {[CkSsh_get_LastMethodSuccess $ssh1] == 0} then {
                puts [CkSsh_lastErrorText $ssh1]
                delete_CkSsh $ssh1
                delete_CkSsh $ssh2
                delete_CkSsh $ssh3
                exit
            }

            puts "$out1"
            set finished1 1
            set numFinished [expr $numFinished + 1]
        }

    }

    if {!$finished2} then {
        set ch2 [CkSsh_QuickCmdCheck $ssh2 $pollTimeoutMs]
        if {$ch2 == -2} then {
            puts [CkSsh_lastErrorText $ssh2]
            delete_CkSsh $ssh1
            delete_CkSsh $ssh2
            delete_CkSsh $ssh3
            exit
        }

        if {$ch2 >= 0} then {
            puts "---- ssh2 channel $ch2 finished ----"
            set out2 [CkSsh_getReceivedText $ssh2 $ch2 "utf-8"]
            if {[CkSsh_get_LastMethodSuccess $ssh2] == 0} then {
                puts [CkSsh_lastErrorText $ssh2]
                delete_CkSsh $ssh1
                delete_CkSsh $ssh2
                delete_CkSsh $ssh3
                exit
            }

            puts "$out2"
            set finished2 1
            set numFinished [expr $numFinished + 1]
        }

    }

    if {!$finished3} then {
        set ch3 [CkSsh_QuickCmdCheck $ssh3 $pollTimeoutMs]
        if {$ch3 == -2} then {
            puts [CkSsh_lastErrorText $ssh3]
            delete_CkSsh $ssh1
            delete_CkSsh $ssh2
            delete_CkSsh $ssh3
            exit
        }

        if {$ch3 >= 0} then {
            puts "---- ssh3 channel $ch3 finished ----"
            set out3 [CkSsh_getReceivedText $ssh3 $ch3 "utf-8"]
            if {[CkSsh_get_LastMethodSuccess $ssh3] == 0} then {
                puts [CkSsh_lastErrorText $ssh3]
                delete_CkSsh $ssh1
                delete_CkSsh $ssh2
                delete_CkSsh $ssh3
                exit
            }

            puts "$out3"
            set finished3 1
            set numFinished [expr $numFinished + 1]
        }

    }

}

CkSsh_Disconnect $ssh1
CkSsh_Disconnect $ssh2
CkSsh_Disconnect $ssh3

delete_CkSsh $ssh1
delete_CkSsh $ssh2
delete_CkSsh $ssh3