[Catalyst][Config][Catalyst::Plugin::ConfigLoader]

あーなるほど、file => /path/to する以外に　CATALYST_CONFIG に設定すると
そいつを読むのね。

sub get_config_path {
    my $c = shift;


    my $appname = ref $c || $c;
    my $prefix  = Catalyst::Utils::appprefix( $appname );
    my $path    = Catalyst::Utils::env_value( $c, 'CONFIG' )
        || $c->config->{ 'Plugin::ConfigLoader' }->{ file }
        || $c->path_to( $prefix );

    my ( $extension ) = ( $path =~ m{\.(.{1,4})$} );

    if ( -d $path ) {
        $path =~ s{[\/\\]$}{};
        $path .= "/$prefix";
    }

    return ( $path, $extension );
}

sub env_value {
    my ( $class, $key ) = @_;

    $key = uc($key);
    my @prefixes = ( class2env($class), 'CATALYST' );

    for my $prefix (@prefixes) {
        if ( defined( my $value = $ENV{"${prefix}_${key}"} ) ) {
            return $value;
        }
    }

    return;
}

http://search.cpan.org/perldoc?Catalyst::Utils
http://search.cpan.org/perldoc?Catalyst::Plugin::ConfigLoader