Onion Config (Python Config)

onion_config is a Python package designed for easy configuration management. It supports loading and validating configuration data from environment variables and configuration files in JSON and YAML formats. It is a Pydantic based custom configuration package for Python projects.

✨ Features

• Main config based on Pydantic schema - https://pypi.org/project/pydantic
• Load environment variables - https://pypi.org/project/python-dotenv
• Load from multiple configs directories
• Load configs from YAML and JSON files
• Update the default config with additional configurations (extra_dir directory)
• Pre-load hook function to modify config data before loading and validation
• Validate config values with Pydantic validators
• Config as dictionary or Pydantic model (with type hints)
• Pre-defined base config schema for common config (BaseConfig)
• Base for custom config loader (ConfigLoader)
• Support Pydantic-v1 and Pydantic-v2

---

🛠 Installation

1. 🚧 Prerequisites

• Install Python (>= v3.9) and pip (>= 23):
  • [RECOMMENDED] Miniconda (v3)
  • [arm64/aarch64] Miniforge (v3)
  • [Python virutal environment] venv

[OPTIONAL] For DEVELOPMENT environment:

• Install git
• Setup an SSH key (video tutorial)

2. 📥 Download or clone the repository

Tip

Skip this step, if you're going to install the package directly from PyPi or GitHub repository.

2.1. Prepare projects directory (if not exists):

# Create projects directory:
mkdir -pv ~/workspaces/projects

# Enter into projects directory:
cd ~/workspaces/projects

2.2. Follow one of the below options [A], [B] or [C]:

OPTION A. Clone the repository:

git clone https://github.com/bybatkhuu/module.python-config.git && \
    cd module.python-config

OPTION B. Clone the repository (for DEVELOPMENT: git + ssh key):

git clone git@github.com:bybatkhuu/module.python-config.git && \
    cd module.python-config

OPTION C. Download source code:

1. Download archived zip file from releases.
2. Extract it into the projects directory.

3. 📦 Install the package

Note

Choose one of the following methods to install the package [A ~ E]:

OPTION A. [RECOMMENDED] Install from PyPi:

Warning

If you wanted to use Pydantic-v1, but if you already installed pydantic-settings and pydantic-core, remove it before installing Pydantic-v1:

pip uninstall -y pydantic-settings
pip uninstall -y pydantic-core

# Then install with Pydantic-v1:
pip install -U onion-config[pydantic-v1]

Warning

If you wanted to use Pydantic-v2, but if you already installed onion-config package just by
pip install -U onion-config command, and this will not install pydantic-settings.
For this case, 'env_prefix' WILL NOT WORK for BaseConfig or BaseSettings without pydantic-settings! This is Pydantic-v2's problem, and there could be some other problems.
So fix these issues re-install onion-config with pydantic-settings:

# Install with pydantic-settings for Pydantic-v2:
pip install -U onion-config[pydantic-settings]

OPTION B. Install latest version directly from GitHub repository:

# Pydantic-v1:
pip install git+https://github.com/bybatkhuu/module.python-config.git[pydantic-v1]

# Pydantic-v2:
pip install git+https://github.com/bybatkhuu/module.python-config.git[pydantic-settings]

OPTION C. Install from the downloaded source code:

# Install directly from the source code:
# Pydantic-v1:
pip install .[pydantic-v1]
# Pydantic-v2:
pip install .[pydantic-settings]

# Or install with editable mode (for DEVELOPMENT):
# Pydantic-v1:
pip install -e .[pydantic-v1]
# Pydantic-v2:
pip install -e .[pydantic-settings]

OPTION D. Install from pre-built release files:

1. Download .whl or .tar.gz file from releases
2. Install with pip:

# Pydantic-v1:
# Install from .whl file:
pip install ./onion_config-[VERSION]-py3-none-any.whl[pydantic-v1]
# Or install from .tar.gz file:
pip install ./onion_config-[VERSION].tar.gz[pydantic-v1]

# Pydantic-v2:
# Install from .whl file:
pip install ./onion_config-[VERSION]-py3-none-any.whl[pydantic-settings]
# Or install from .tar.gz file:
pip install ./onion_config-[VERSION].tar.gz[pydantic-settings]

OPTION E. Copy the module into the project directory (for testing):

# Install python dependencies:
pip install -r ./requirements/requirements.core.txt

# Pydantic-v1:
pip install -r ./requirements/requirements.pydantic-v1.txt
# Pydantic-v2:
pip install -r ./requirements/requirements.pydantic-settings.txt

# Copy the module source code into the project:
cp -r ./src/onion_config [PROJECT_DIR]
# For example:
cp -r ./src/onion_config /some/path/project/

🚸 Usage/Examples

Simple

examples/simple/.env

ENV=production

examples/simple/configs/1.base.yml:

env: test

app:
  name: "My App"
  version: "0.0.1"
  nested:
    key: "value"

examples/simple/configs/2.extra.yml:

app:
  name: "New App"
  nested:
    some: "value"
  description: "Description of my app."

another_val:
  extra: 1

examples/simple/main.py

import pprint

from loguru import logger
try:
    import pydantic_settings

    _has_pydantic_settings = True
except ImportError:
    _has_pydantic_settings = False

from onion_config import ConfigLoader, BaseConfig


class ConfigSchema(BaseConfig):
    env: str = "local"

try:
    config: ConfigSchema = ConfigLoader(config_schema=ConfigSchema).load()
except Exception:
    logger.exception("Failed to load config:")
    exit(2)

if __name__ == "__main__":
    logger.info(f"All: {config}")
    logger.info(f"App name: {config.app['name']}")

    if _has_pydantic_settings:
        # Pydantic-v2:
        logger.info(f"Config:\n{pprint.pformat(config.model_dump())}\n")
    else:
        # Pydantic-v1:
        logger.info(f"Config:\n{pprint.pformat(config.dict())}\n")

Run the examples/simple:

cd ./examples/simple

python ./main.py

Output:

2023-09-01 00:00:00.000 | INFO     | __main__:<module>:29 - All: env='production' another_val={'extra': 1} app={'name': 'New App', 'version': '0.0.1', 'nested': {'key': 'value', 'some': 'value'}, 'description': 'Description of my app.'}
2023-09-01 00:00:00.000 | INFO     | __main__:<module>:30 - App name: New App
2023-09-01 00:00:00.000 | INFO     | __main__:<module>:35 - Config:
{'another_val': {'extra': 1},
 'app': {'description': 'Description of my app.',
         'name': 'New App',
         'nested': {'key': 'value', 'some': 'value'},
         'version': '0.0.1'},
 'env': 'production'}

Advanced

examples/advanced/.env.base:

ENV=development
DEBUG=true
APP_NAME="Old App"
ONION_CONFIG_EXTRA_DIR="extra_configs"

examples/advanced/.env.prod:

ENV=production
APP_NAME="New App"
APP_SECRET="my_secret"

examples/advanced/configs/config.yml:

env: local

app:
  name: "My App"
  port: 9000
  bind_host: "0.0.0.0"
  version: "0.0.1"
  ignore_val: "Ignore me"

logger:
  output: "file"

examples/advanced/configs/logger.json:

{
    "logger": {
        "level": "info",
        "output": "stdout"
    }
}

examples/advanced/configs_2/config.yml:

extra:
  config:
    key1: 1

examples/advanced/configs_2/config_2.yml:

extra:
  config:
    key2: 2

examples/advanced/extra_configs/extra.json:

{
    "extra": {
        "type": "json"
    }
}

examples/advanced/schema.py:

from enum import Enum
from typing import Union

import pydantic
from pydantic import Field, SecretStr
_has_pydantic_settings = False
if "2.0.0" <= pydantic.__version__:
    try:
        from pydantic_settings import SettingsConfigDict

        _has_pydantic_settings = True
    except ImportError:
        pass

from onion_config import BaseConfig


# Environments as Enum:
class EnvEnum(str, Enum):
    LOCAL = "local"
    DEVELOPMENT = "development"
    TEST = "test"
    DEMO = "demo"
    STAGING = "staging"
    PRODUCTION = "production"

# App config schema:
class AppConfig(BaseConfig):
    name: str = Field("App", min_length=2, max_length=32)
    bind_host: str = Field("localhost", min_length=2, max_length=128)
    port: int = Field(8000, ge=80, lt=65536)
    secret: SecretStr = Field(..., min_length=8, max_length=64)
    version: str = Field(..., min_length=5, max_length=16)
    description: Union[str, None] = Field(None, min_length=4, max_length=64)

    if _has_pydantic_settings:
        # Pydantic-v2:
        model_config = SettingsConfigDict(extra="ignore", env_prefix="APP_")
    else:
        # Pydantic-v1:
        class Config:
            extra = "ignore"
            env_prefix = "APP_"

# Main config schema:
class ConfigSchema(BaseConfig):
    env: EnvEnum = Field(EnvEnum.LOCAL)
    debug: bool = Field(False)
    app: AppConfig = Field(...)

examples/advanced/config.py:

from loguru import logger

from onion_config import ConfigLoader

from schema import ConfigSchema


# Pre-load function to modify config data before loading and validation:
def _pre_load_hook(config_data: dict) -> dict:
    config_data["app"]["port"] = "80"
    config_data["extra_val"] = "Something extra!"
    return config_data

config = None
try:
    _config_loader = ConfigLoader(
        config_schema=ConfigSchema,
        configs_dirs=["configs", "configs_2", "/not_exists/path/configs_3"],
        env_file_paths=[".env", ".env.base", ".env.prod"],
        pre_load_hook=_pre_load_hook,
        config_data={"base": "start_value"},
        warn_mode="ALWAYS",
    )
    # Main config object:
    config: ConfigSchema = _config_loader.load()
except Exception:
    logger.exception("Failed to load config:")
    exit(2)

examples/advanced/main.py:

import pprint

from loguru import logger
try:
    import pydantic_settings
    _has_pydantic_settings = True
except ImportError:
    _has_pydantic_settings = False

from config import config


if __name__ == "__main__":
    logger.info(f"All: {config}")
    logger.info(f"ENV: {config.env}")
    logger.info(f"DEBUG: {config.debug}")
    logger.info(f"Extra: {config.extra_val}")
    logger.info(f"Logger: {config.logger}")
    logger.info(f"App: {config.app}")
    logger.info(f"Secret: '{config.app.secret.get_secret_value()}'\n")

    if _has_pydantic_settings:
        # Pydantic-v2:
        logger.info(f"Config:\n{pprint.pformat(config.model_dump())}\n")
    else:
        # Pydantic-v1:
        logger.info(f"Config:\n{pprint.pformat(config.dict())}\n")

    try:
        # This will raise ValidationError
        config.app.port = 8443
    except Exception as e:
        logger.error(f"{e}\n")

Run the examples/advanced:

cd ./examples/advanced

python ./main.py

Output:

2023-09-01 00:00:00.000 | INFO     | onion_config._base:load:143 - Loading all configs...
2023-09-01 00:00:00.000 | WARNING  | onion_config._base:_load_dotenv_file:201 - '/home/user/workspaces/projects/onion_config/examples/advanced/.env' file is not exist!
2023-09-01 00:00:00.000 | WARNING  | onion_config._base:_load_configs_dir:257 - '/not_exists/path/configs_3' directory is not exist!
2023-09-01 00:00:00.000 | SUCCESS  | onion_config._base:load:171 - Successfully loaded all configs!
2023-09-01 00:00:00.000 | INFO     | __main__:<module>:19 - All: env=<EnvEnum.PRODUCTION: 'production'> debug=True app=AppConfig(name='New App', bind_host='0.0.0.0', port=80, secret=SecretStr('**********'), version='0.0.1', description=None) extra={'config': {'key1': 1, 'key2': 2}, 'type': 'json'} extra_val='Something extra!' logger={'output': 'stdout', 'level': 'info'} base='start_value'
2023-09-01 00:00:00.000 | INFO     | __main__:<module>:20 - ENV: production
2023-09-01 00:00:00.000 | INFO     | __main__:<module>:21 - DEBUG: True
2023-09-01 00:00:00.000 | INFO     | __main__:<module>:22 - Extra: Something extra!
2023-09-01 00:00:00.000 | INFO     | __main__:<module>:23 - Logger: {'output': 'stdout', 'level': 'info'}
2023-09-01 00:00:00.000 | INFO     | __main__:<module>:24 - App: name='New App' bind_host='0.0.0.0' port=80 secret=SecretStr('**********') version='0.0.1' description=None
2023-09-01 00:00:00.000 | INFO     | __main__:<module>:25 - Secret: 'my_secret'

2023-09-01 00:00:00.000 | INFO     | __main__:<module>:30 - Config:
{'app': {'bind_host': '0.0.0.0',
         'description': None,
         'name': 'New App',
         'port': 80,
         'secret': SecretStr('**********'),
         'version': '0.0.1'},
 'base': 'start_value',
 'debug': True,
 'env': <EnvEnum.PRODUCTION: 'production'>,
 'extra': {'config': {'key1': 1, 'key2': 2}, 'type': 'json'},
 'extra_val': 'Something extra!',
 'logger': {'level': 'info', 'output': 'stdout'}}

2023-09-01 00:00:00.000 | ERROR    | __main__:<module>:36 - "AppConfig" is immutable and does not support item assignment

👍

---

🌎 Environment Variables

.env.example:

# ENV=development
# DEBUG=true

ONION_CONFIG_EXTRA_DIR="./extra_configs"

---

🧪 Running Tests

To run tests, run the following command:

# Install core dependencies:
pip install -r ./requirements/requirements.core.txt

# Pydantic-v1:
pip install -r ./requirements/requirements.pydantic-v1.txt
# Pydantic-v2:
pip install -r ./requirements/requirements.pydantic-settings.txt

# Install python test dependencies:
pip install -r ./requirements.test.txt

# Run tests:
python -m pytest -sv -o log_cli=true
# Or use the test script:
./scripts/test.sh -l -v -c

🏗️ Build Package

To build the python package, run the following command:

# Install python build dependencies:
pip install -r ./requirements/requirements.build.txt

# Build python package:
python -m build
# Or use the build script:
./scripts/build.sh

📝 Generate Docs

To build the documentation, run the following command:

# Install python documentation dependencies:
pip install -r ./requirements/requirements.docs.txt

# Serve documentation locally (for development):
mkdocs serve
# Or use the docs script:
./scripts/docs.sh

# Or build documentation:
mkdocs build
# Or use the docs script:
./scripts/docs.sh -b

📚 Documentation

• Docs
• Home

Getting Started

• Prerequisites
• Installation
• Configuration
• Examples
• Error Codes

API Documentation

Development

• Test
• Build
• Docs
• CI/CD
• Scripts
• File Structure
• Sitemap
• Contributing
• Roadmap

Release Notes

About

• FAQ
• Authors
• Contact
• License

---

📑 References

• https://docs.pydantic.dev
• https://github.com/pydantic/pydantic
• https://docs.pydantic.dev/latest/usage/pydantic_settings
• https://github.com/pydantic/pydantic-settings
• https://saurabh-kumar.com/python-dotenv
• https://github.com/theskumar/python-dotenv
• https://packaging.python.org/tutorials/packaging-projects