Unified Configuration Setting Access in Configuration Management Systems

The behavior of software is often governed by a large set of configuration settings, distributed over several stacks in the software system. These settings are often manifested as plain text files that exhibit different formats and syntax. Configuration management systems are introduced to manage the complexity of provisioning and distributing configuration in large scale software. Globally patching configuration settings in these systems requires, however, introducing text manipulation or external templating mechanisms, that paradoxically lead to increased complexity and, eventually, to misconfigurations. These issues manifest through crashes or bugs that are often only discovered at runtime. We introduce a framework called Elektra, which integrates a centralized configuration space into configuration management systems to avoid syntax errors and avert the overriding of default values, to increase developer productivity. Elektra enables mounting different configuration files into a common, globally shared data structure to abstract away from the intricate details of file formats and configuration syntax and introduce a unified way to specify and patch configuration settings as key/value pairs. In this work, we integrate Elektra in the configuration management tool Puppet. Additionally, we present a user study with 14 developers showing that Elektra enables significant productivity improvements over existing configuration management concepts. Our study participants performed significantly faster using Elektra in solving three representative scenarios that involve configuration manipulation, compared to other general-purpose configuration manipulation methods.