[Expectperl-discuss] ssh script to propegate commands to multiple servers

[Brett M. <bre...@qa...>]

Folks,

I am new to expectperl and am having some conceptual troubles (I think). I
am using ssh to issue a command to multiple hosts read from a text file. I
have kludged together some expect code to handle some responses I may get
to the ssh command. I would like to make my code a little neater and be
able to trap the condition where the host does not respond at all to the
command (ie it is powered off at the time). Therefore I have the following
questions (to be followed by a section of my code to illustrate my
problem).

   I really hate the whole $skiphost thing and would really like to be able
   to just issue a next; for the conditions which require no further
   interaction with that particular host (thus returning to the top of my
   while loop). This however does not seem to work. If I do this, the
   expect call is not broken and continues until timeout and then some
   other code in the whileloop is eroniously executed. Is there a means of
   doing this (ie something like exp_next; instead of exp_continue)?
   How can i differentiate a situation where the host just does not
   respond? I thought to do this by catching when the expect call timesout
   but with the current logic it timesout in every condition (hopefully a
   solution to pont 1 above will also resolve this issue).

Kind Regards
Brett



while (<HOSTS>) {
  chomp();
  @nexthost = split(/,/, $_); # take first field of each line as a valid
host (comma seperated data)

# Issue the command to the current host
        $ssh = Expect->spawn("ssh $nexthost[0] $mycommand")
            or die "Couldn't start program: $!\n"; #$ssh->debug(1);
$ssh->log_file("exp.log");

        # prevent the program's output from being shown on our STDOUT
        $ssh->log_stdout(0);

 $ssh->expect(20,
        [ qr/continue/i, sub { my $self = shift;
                $self->send("yes\n");
                exp_continue; }],
        [ qr/denied/i, sub { print "your password for $nexthost[0] was
incorrect - please reenter: ";
                ReadMode 'noecho';
                $newpass = <STDIN>; # read the next line
                chomp($newpass);
                ReadMode 'normal';
                if ($newpass) {$password = $newpass;}
                $newpass="";
                print "\n";
                exp_continue; }],
        [ qr/password:/i, sub { my $self = shift;
                $self->send("$password\n");
                exp_continue; }],
        [ qr/publickey/i, sub { print "your login to $nexthost[0] failed -
maybe you dont have an account there ";
                $skiphost = "yes";
                exp_continue; }],
        [ qr/not known/i, sub { print "host $nexthost[0] is unknown\n";
                $skiphost = "yes";
                exp_continue; }],
        [ qr/closed/i, sub { print "host $nexthost[0] closed the connection
- your password may have expired here\n";
                $skiphost = "yes";
                exp_continue; }],
        [ qr/connection/i, sub { print "host $nexthost[0] closed the
connection\n";
                $skiphost = "yes";
                exp_continue; }],
        [ qr/refused/i, sub { print "host $nexthost[0] is not responding on
port 22\n";
                $skiphost = "yes";
                exp_continue; }],
 );

if ($skiphost) {
        $skiphost = "";
        next;
        print "you shouldnt see this as it should have skipped"; }

# close the expect for ssh
$ssh->soft_close();

<some other stuff>
<more other stuff>

}  # loop to next host

close HOSTS;







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