debconf-get-selections

debconf-get-selections

#!/usr/bin/perl
#
#  The goal of this is to read a bunch of variables from debconf
#  To implement a "late_command_runparts" like function.
#  Ie, you would populate the preseed with content like:
#    late-command-d  late-command/90-fix-hosts string content-for-fix-hosts
#    late-command-d  late-command/10-install-my-packages string payload
#
#  Then, in the actual late_command, we would suck out all those
#  values, and run them by doing something like this:
#   mkdir /root/late-command.d
#   ./late-command-d late-command/ /root/late-command.d
#   run-parts /root/late-command.d
#
# TODO:
#   * remove the variables from debconf after used
#   * expect values to be base64 encoded and base64 decode them
#     or you have to debconf-escape them.

use strict;
use warnings;
use Debconf::Db;
use MIME::Base64;

#sub debconf_unescape {
#   my($unescaped, $escaped)
#   $unescaped = @_[0]
#   for (split(/(\\.)/, $input) {
#	   s/\\(.)/$1 eq "n" ? "\n" : $1/eg;
#	   print;
#   }
#}

Debconf::Db->load(readonly => "true");

my $prefix = $ARGV[0];
my $prefix_len = length($prefix);
my $out_d = $ARGV[1];

if (! -d $out_d) {
   mkdir($out_d) or die "Cannot make directory: $out_d";
}

my $qi = Debconf::Question->iterator;

while (my $q = $qi->iterate) {
	my ($name, $type, $value) = ($q->name, $q->type, $q->value);
   next if (substr($name, 0, $prefix_len) ne $prefix);
   my $fname = substr($name, $prefix_len);
   my $fpath = $out_d . "/" . $fname;
   my $decoded = "";
   
   print $fname . "\n";
   if ($type eq "base64") {
      $decoded = decode_base64($value);
   } else {
      $decoded = decode_unescape($value);
   }
   open(FNAME, ">$fpath") or die $!;
   print FNAME "$value";
   close(FNAME);
}

Note to self: type cannot be "base64" (debconf will complain), so I considered pre/postfixing name with "b64-" to indicate payload was base64.