Swift Logging Environment

Create custom loggers scoped by subsystem and log level. Provides precise, fine-grained control over logging behavior across different environments.

Requirements

• Swift 6.1+
• Platforms:
  • Linux
  • macOS 15+
  • iOS 18+
  • tvOS 18+
  • watchOS 11+
  • visionOS 2+

Installation

Use Swift Package Manager; add the dependency to your Package.swift file:

.package(url: "https://github.com/binarybirds/swift-log-env", from: "2.0.0"),

Then add LoggingEnvironment to your target dependencies:

.product(name: "LoggingEnvironment", package: "swift-log-env"),

Update the packages and you are ready.

Usage

API documentation is available at the following link.

Basic example

import LoggingEnvironment

let libLogger = Logger.subsystem("my-lib", .notice)
let appLogger = Logger.subsystem("my-app", .notice)

// LOG_LEVEL=info MY_LIB_LOG_LEVEL=trace swift run MyApp

This imports LoggingEnvironment and creates two loggers scoped to my-lib and my-app with a default .notice level. At runtime, environment variables override these levels: LOG_LEVEL sets a global minimum, while MY_LIB_LOG_LEVEL applies a more specific level to the my-lib subsystem, enabling per-subsystem logging control without code changes.

Development

• Build: swift build
• Test:
  • local: swift test
  • using Docker: make docker-test
• Format: make format
• Check: make check

Contributing

Pull requests are welcome. Please keep changes focused and include tests for new logic.