klein-config 3.1.8

Read and manage config from environment variables and files

Py-Env-Aware Config

Module to provide config management

Usage

from klein_config import get_config

# Can be overriden with env variable MY_CONFIG_SETTING
config = get_config({"my": {"config": {"setting": "initialised value"}})

# Access via `get` accessor with no backup (raises ConfigMissingException if not found).
value = config.get("my.config.setting")

# Access via `get` accessor method with a backup.
backup_value = config.get("not.a.setting", "backup value")

# Access via `dict` (raises KeyError if not found).
same_value = config["my.config.setting"]

# Sub-configs are created if the value is another `dict`.
intermediate_config = config["my.config"]
same_value_again = intermediate_config["setting"]

Structure

Internally the config object uses the ConfigTree structure that is part of pyhocon. This can be traversed easily with the get method using dot notation as outlined above.

Config Initialisation

The get_config function looks for :

• argument --common or environmental variable PY_ENV_AWARE_COMMON to specify a valid filepath for a common config file (in either JSON or YAML format); and
• argument --config or environmental variable PY_ENV_AWARE_CONFIG to specify a valid filepath for a config file

However, passing both the environmental variables and the arguments for either config or common is NOT accepted as it is ambiguous what is expected.

You can also pass a dict into get_config function.

Order precedence

The configs are applied to the config object as follows:

1st: Common config as identified via argument --common or environmental variable PY_ENV_AWARE_COMMON 2nd: Config that is injected via the Class constructor 3rd: Config that is identified via the argument --config or environmental variable PY_ENV_AWARE_CONFIG

Configs will override any previous values as they are applied

Environment Aware

The module is "Environment Aware" this means that it will test for envrionments variables first. If a valid variable exists then this will be used regardless of any config that may have been supplied.

The path is transformed by converting the string to uppercase and replacing all dots with underscores.

my.config.setting => MY_CONFIG_SETTING

Sub-config items are still overriden by the same environment variables as in the root config.

Development

This project uses pipenv. To install it, run pip install pipenv.

Development

pipenv install --dev

Testing

pipenv run python -m pytest

For test coverage you can run:

pipenv shell
pipenv run python -m pytest --cov-report term --cov src/ tests/

Troubleshooting

If you are unable to run pipenv shell and are having permission errors, you can spin up a virtual environment to run the pipenv commands a different way

1. Run pip install virtualenv to install a virtual environment
2. While in your projects root directory, run virtual env venv
3. Then to start your virtual environment, run source venv/bin/activate
4. Then run this command pipenv install --dev and you should now be able to run the commands above

License

This project is licensed under the terms of the Apache 2 license, which can be found in the repository as LICENSE.txt