Split configuration in typo3conf into managed, manual and server specific parts - typo3

Question

In TYPO3, Version 6.1.5, I'd like to split my configuration in typo3conf in three parts:
One part generated by the install-tool, under version control.
One manually managed part, under version control.
One manually managed part, containing server specific stuff, not under version control. Contains e.g. database credentials.
I've tried to do it like this:
is done using LocalConfiguration.php,
is done using AdditionalConfiguration.php
is done by and additional file, included by the AdditionalConfiguration.php.
This does not work, as it seams that the files are evaluated in this order:
LocalConfiguration.php
AddtitionalConfiguration.php
LocalConfiguration.php
So the changes from my server specific file (and AdditionalConfiguration.php) are simple overwritten by the stuff from LocalConfiguration.php.
Any idea how to get around something like this?

Answer 1

First: don't apply any manual changes in your: LocalConfiguration.php file as it will be removed after each operation in the Install Tool, Extension Manager etc.
For adding custom configuration, you should use AddtitionalConfiguration.php file which isn't changed (as probably you know while you are using it). In this additional conf you need to use 'old' syntax for overwriting values, ie:
<?php
$GLOBALS['TYPO3_CONF_VARS']['DB']['database']='some_db_loc';
$GLOBALS['TYPO3_CONF_VARS']['DB']['host']='localhost';
$GLOBALS['TYPO3_CONF_VARS']['DB']['username']='jost';
$GLOBALS['TYPO3_CONF_VARS']['DB']['password']='yourpass';
finally at the end of the additional conf use common include() for including next PHP file in which you can overwrite these values again:
#include('jost_localconf_dont_commit.php');
At least in TYPO3 ver. 6.1.1 this scenario works like a charm.
EDIT: also take a look at Viktor's answer according to accessing the properties in additional config.
BTW: I'm not really sure why you need to commit AdditionalConfiguration.php , IMHO it should be ignored in the git, and on every environment it should have this file filled with local data typical for this env. Main (production) instance should keep whole its config in LocalConfiguration.php

Answer 2

Just one things to add to biesior's answer:
For security reasons, it is even better not to have the DB credentials in AdditionalConfiguration.php. It's better to include a PHP file with the credentials from a path that is outside the document root of the host. Therefore if PHP doesn't work properly, the file cannot be downloaded and the DB credentials are not exposed.