To change serf agent's tag that not using serf RPC ( by perl script).

changetag.pl

#!/usr/bin/perl

print "\n### DEBUG:: changetag";

my $payload = <STDIN>;

print "DEBUG: payload: $payload\n";

my ($target, $method, $key, $value) = split(/::/, $payload);

print "DEBUG: $ENV{SERF_SELF_NAME}, $target, method = $method\n";

if ($ENV{SERF_SELF_NAME} eq $target) {
        print "DEBUG: match target \n";

        my $cmd;
        if ($method eq 'set') {
                $cmd = "/usr/bin/serf tags -set $key=$value";
        } elsif ($method eq 'delete') {
                $cmd = "/usr/bin/serf tags -delete $key";
        }
        print "system: cmd = $cmd\n";

        my $system = system("$cmd");
        print "system: $system\n";
}

exit;