You could also use mod_perl directives and stick it right in your apache config file. Many mason apps already have a fair amount of stuff in the apache config file.

Try something like:

<Perl> 
Package MyAppConfig;
my $cfg = {
    DBMpath => '/foo/bar/quux',
    salt    => 'NaCl',
    baseDir => '/baz/bar/foo',
};
sub salt {
    my ($class,$salt) = @_;

    $cfg->{salt} = $salt if $salt;

    return $cfg->{salt};
}
# Write accessors/mutators as desired for the other elements too.
</Perl>
[download]

You should be able to access the config from your Mason app. The accessor/mutators aren't realy necessary, they just make accessing data a bit cleaner. If you write accessors, consider putting them in an actual separate module file. Then put only the $cfg variable in your apache config (or go all out and set the values with mutator sub calls).

<Perl>
MyAppConfig->salt('NaCl');
MyAppConfig->DBMpath('/foo/bar/gack');
</Perl>
[download]

or you could even use plain apache configuration:

PerlAddVar MySalt NaCl
PerlAddVar MyDBMPath /foo/bar/yak
PerlAddVar MyBaseDir /bar/foo/mkay
[download]

Access these with:

my $salt = $r->dir_config->get('MySalt');
[download]

What is best really depends on your needs. It may not even make sense for you to put the configuration in your apache configuration.

Good luck.