config-rs

Layered configuration system for Rust applications (with strong support for 12-factor applications).

• Set defaults
• Set explicit values (to programmatically override)
• Read from JSON, TOML, YAML, INI, RON, JSON5 files
• Read from environment
• Loosely typed — Configuration values may be read in any supported type, as long as there exists a reasonable conversion
• Access nested fields using a formatted path — Uses a subset of JSONPath; currently supports the child ( redis.port ) and subscript operators ( databases[0].name )

Please note that this library can not be used to write changed configuration values back to the configuration file(s)!

Usage

Feature flags

• ini - Adds support for reading INI files
• json - Adds support for reading JSON files
• yaml - Adds support for reading YAML files
• toml - Adds support for reading TOML files
• ron - Adds support for reading RON files
• json5 - Adds support for reading JSON5 files

Support for custom formats

Library provides out of the box support for most renowned data formats such as JSON or Yaml. Nonetheless, it contains an extensibility point - a Format trait that, once implemented, allows seamless integration with library's APIs using custom, less popular or proprietary data formats.

See custom_file_format example for more information.

More

See the documentation or examples for more usage information.

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/license/mit)

at your option.