ConfigClasses

Think python's dataclasses module PEP-557 for configuration. Pulls in configuration from various sources into a single integrated, global configuration object. The configuration data can be reloaded on demand.

Read the Documentation

Features

• Globally accessable configuration classes
• Easily pull from many sources of configuration:
  • Environment variables
  • Command line arguments
  • Dotenv files
  • Json files
  • Toml files
  • Ini files
  • Consul Key/Value store
  • Planned sources: AWS Parameter Store, Etcd, Redis
• prioritization when multiple sources are used together.
• Typed configuration values out of the box
  • primitive types supported out of the box
  • Enum types can be used to specify valid values
  • converter functions can turn stringly typed or primitive types into complex types such as dicts or classes

Quickstart

from configclasses import configclass, LogLevel, Environment

# Wrap your configuration class in the `configclass` decorator
# By default, it looks for matching variables in the environment.
@configclass
class Configuration:
    HOST: str
    PORT: int
    DB_HOST: str = "localhost"  # Default if `DB_HOST` is not set as an environment variable.
    DB_PORT: int = 5432         # Default if `DB_PORT` is not set as an environment variable.
    ENVIRONMENT: Environment    # Enum used to specify the set of valid values
    LOG_LEVEL: LogLevel         # Enum with the same values as python's logging level constants

# Instantiating a `Configuration` will always return the same object
config = Configuration()

# access fields by name
config.HOST == "localhost"

# `int` typed fields will be ints
config.PORT == 8080

# Fields with `Enum` types will have variants as values
config.ENVIRONMENT == Environment.Development

# Reload config values from sources
config.reload()

# Configuration objects can now have different values
config.ENVIRONMENT == Environment.Production


# Config classes can also be configured with other `sources`
from configclasses.sources import DotEnvSource, EnvironmentSource

@configclass(sources=[DotEnvSource(), EnvironmentSource()])
class Configuration:
    HOST: str
    PORT: int
    DB_ADDRESS: str = "localhost"
    DB_PORT: int = 5432
    ENVIRONMENT: Environment
    LOG_LEVEL: LogLevel

# First, a `.env` file will be searched for values, then
# any values that are not present there will be searched
# for in the program's environment.
config = Configuration()

TODO

• Reload method
• CLI source
• Deal with sources that only provide stringly typed values and values that provide other primitives
• Type converters
• Multiple named configuration objects
• Some sources might be case-insensitive.
• Async/Sync versions of sources
• Research and design push updates (as opposed to polling updates)
• Better error messages when config values are missing from all sources
• Audit exception types raised.
• Comprehensive docs Includes docs on adding your own sources.

Contribution

Feature requests, issues, and Pull Requests welcome. Please file an issue with a feature request or suggestion intended to prompt discussion before submitting a PR that implements new functionality to avoid writing code that conflicts with the goals of the project.

License

Licensor solely permits licensee to license under either of the following two options

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

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions.