Docker: switch to alpinelinux and cpm

Change-Id: I78210b14a3620fcba36ee7a49f83cd5cd8acc1f3
diff --git a/script/derekovecs-server b/script/derekovecs-server
index d6fc6c5..5cd0c8d 100755
--- a/script/derekovecs-server
+++ b/script/derekovecs-server
@@ -65,9 +65,7 @@
 my $title="";
 my $training_args="";
 
-getopts('d:D:Gil:p:m:n:M:C') or usage();
-
-sub usage() {
+sub usage {
   print STDERR <<EOF;
 non-server mode usage: MOJO_CONFIG=`pwd`/example.conf $0 [-h] [-d <file>]
 -h        : this (help) message
@@ -80,6 +78,8 @@
   exit;
 }
 
+getopts('d:D:Gil:p:m:n:M:Ch') or usage();
+
 if($opt_M) {
   open my $handle, '<:encoding(UTF-8)', $opt_M
     or die "Can't open '$opt_M' for reading: $!";