confme 0.0.3

Easy configuration management in python

ConfMe: Configuration Made Easy 💖

ConfMe is a simple to use, production ready application configuration management library, which takes into consideration the following three thoughts:

1. Access to configuration values must be safe at runtime. No myconfig['value1']['subvalue'] anymore!
2. The configuration must be checked for consistency at startup e.g. type check, range check, ...
3. Secrets shall be injectable from environment variables

ConfMe makes all these features possible with just a few type annotations on plain Python objects.

Installation

ConfMe can be installed from the official python package repository pypi

pip install confme

Or, if you're using pipenv:

pipenv install confme

Or, if you're using poetry:

poetry add confme

Basic Usage of confme

Define your config structure as plain python objects with type annotations:

from confme import configclass, load_config

@configclass
class DatabaseConfig:
    host: str
    port: int
    user: str

@configclass
class MyConfig:
    name: int
    database: DatabaseConfig

Create a configuration yaml file with the same structure as your configuration classes have:

name: "Database Application"
database:
    host: "localhost"
    port: 5000
    user: "any-db-user"

Load the yaml file into your Python object structure and access it in a secure manner:

my_config = load_config(MyConfig, 'config.yaml')

print(f'Using database connection {my_config.database.host} '
      f'on port {my_config.database.port}')

In the background the yaml file is parsed and mapped to the defined object structure. While mapping the values to object properties, type checks are performed. If a value is not available or is not of the correct type, an error is generated already when the configuration is loaded.

Supported Annotations

At the moment the following type annotations are supported:

• str
• int
• float
• Secret
• Range not yet implemented
• Enum not yet implemented

Secret['ENV_NAME', TYPE]

With the Secret annotation you can inject secrets from environment variables directly into your configuration structure. This is especially handy when you're deploying applications by using docker. Therefore, let's extend the previous example with a Secret annotation:

...
from confme import configclass, load_config
from confme.annotation import Secret

@configclass
class DatabaseConfig:
    ...
    password: Secret['highSecurePassword', str]

Now set the password to the defined environment variable:

export highSecurePassword="This is my password"

Load your config and check for the injected password.

my_config = load_config(MyConfig, 'config.yaml')
print(f'My password is: {my_config.database.password}')

Range[NUMBER_TYPE, FROM, TO]

...
from confme import configclass, load_config
from confme.annotation import Secret

@configclass
class DatabaseConfig:
    ...
    password: Range[int, 2, 3]

SELECTION[args...]

LICENSE

ConfMe is released under the MIT license.