config-proxy

This is a Python module that enables you to setup paths for both json configuration and configuration from env variables.

It automatically looks into environmental variables and either uses its value, or looks it up in json configuration file or falls back to default.

Install

Either clone from this repository or use pip / poetry like so:

Via pip

pip install config-proxy

Using poetry

poetry add config-proxy

Usage

Basic usage

If your configuration file is either called config.json and is expected in the current working directory or its location is set using CONFIG_PATH environmental variable, the usage is fairly easy:

config.json

{
  "database": {
    "host": "mydbhost.databases.com"
  }
}

main.py

from config_proxy import StringProperty

database_host = StringProperty(path="database.host", env="DATABASE_HOST", default="localhost")

print(database_host.value)

$ python main.py
mydbhost.databases.com

$ DATABASE_HOST="overridden.database.com" python main.py
overridden.database.com

Advanced usage

If you want to specify configuration file path and customize env variable that stores the path, you have to extend the ConfigProxy class and overload attributes you wish to change.

my-special-config.json

{
    "database": {
        "host": "mydbhost.databases.com"
    }
}

custom.py

from config_proxy import ConfigProxy as _ConfigProxy, StringProperty

class ConfigProxy(_ConfigProxy):
    env_location = "ENV_VARIABLE_THAT_CONTAINS_MY_CONFIG_PATH"
    config_file_names = ["my-special-config.json"]

Please note, that StringProperty now does not know it should use your subclass instead, do not forget to specify it when creating the property:

database_host = StringProperty(path="database.host", env="DATABASE_HOST", default="localhost", proxy=ConfigProxy)

print(database_host.value)

If you want to specify a custom config file, you can use:

$ ENV_VARIABLE_THAT_CONTAINS_MY_CONFIG_PATH="/actual/path/to/my/config.json" python custom.py
mydbhost.databases.com