Array-based Config vs Environment Variable Mapping for Production Secrets

Zend Framework (Laminas) employs a merged configuration system where global settings are typically overridden by local files. When transitioning from a local development environment to a production cluster, there is a design choice between utilizing static array-based configuration files and mapping environment variables into the config array.

Array-based configurations benefit from opcode caching, reducing the overhead of reading settings on every request. However, this approach requires strict version control management to avoid leaking secrets and often necessitates a cache clear during rolling updates to prevent stale configuration bugs.

Environment variable mapping increases security by keeping credentials out of the codebase, but it introduces potential type-casting issues in PHP and adds a slight performance overhead during the bootstrap process.

Configuration Constraints

• Requirement for high-performance request handling via config caching.
• Strict security requirements for production database credentials.
• Need for consistency across multiple containerized instances.

Which approach provides the best balance between boot performance and secret security in a containerized production environment? Does the use of environment variables significantly degrade the benefits of the config_cache_enabled flag?