singleconfig

Singleconfig is a software design pattern and practice that centralizes configuration data for an application or system into a single source of truth. The goal is to provide a consistent, authoritative configuration that can be consumed by all components, environments, and services. A singleconfig can take the form of a configuration file, a remote configuration service, or a combination where a local file is augmented by remote values.

Core concepts include a single source of truth, hierarchical overrides, and environment- or tenant-specific profiles. Typical implementations support merging rules, allowing base settings to be overridden by environment, region, or feature-specific values. Many approaches also include validation, schema enforcement, type safety, and the ability to reload configurations at runtime without restarting the application.

Common patterns and implementations involve embedded config files (JSON, YAML, or TOML), environment variable overlays, and remote config services that publish updates. Some systems expose a small API for components to subscribe to changes, enabling dynamic reconfiguration.

Benefits of singleconfig include reduced duplication, improved consistency across services, easier deployment and rollback, and enhanced testability through a reproducible configuration state. However, it introduces potential drawbacks such as a single point of failure, the need for robust access control and secret management, performance considerations, and governance requirements to prevent drift.

Singleconfig is related to broader configuration management concepts, including the twelve-factor app principles, feature flags, and strategies for multi-environment deployments. It is commonly used in microservice architectures and large-scale applications requiring centralized control over settings.