merge-conf

A configuration aggregator for multiple configuration sources.

Using this library, it is easy to combine multiple configuration or settings sources. The following items can be combined:

• a fixed object with default settings
• command-line arguments
• environment variables
• configuration files like
  • .env files
  • python files
  • ConfigParser style ini files
  • toml files
  • yaml files
  • json files

The basic entry point is the so called MultiConfigurationSource. It can be initialized with an optional, existing configuration object. Multiple ConfigurationSource objects can be added. These objects will be traversed in order of insertion. Each of these instances create a dictionary of configuration entries that will be used to extend or override the previous ones. The resulting object can be received using the read_configuration method.

Example

import merge_conf

config = None # Create existing object
arguments = None # Argument parser result namespace

source = merge_conf.MultiConfigurationSource(config)
source.add(merge_conf.ConfigFileConfigurationSource(
    # Configuration file path
))
source.add(merge_conf.EnvironmentVariableSource("MY_APP"))
source.add(merge_conf.ArgParseSource(arguments))

config = source.read_configuration()

In this example, the configuration object will be created first. Then, the configuration file will be created. Afterwards, all environment variables starting with MY_APP_ will be used for configuration. The final configuration item will be fetched from the argparse module.

The trick is to created the configuration namespaces with a little sure instinct, so that items can be overridden.

Installing

The package can be installed using pip. Most support comes out of the box, but for the following features an extra must be activated:

.env file support (dotenv) yaml file support (yaml) toml file support (toml)

Licensing

This library is published under BSD-3-Clause license.

Versioning

This library follows semantic versioning 2.0. Any breaking change will produce a new major release. Versions below 1.0 are considered to have a unstable interface.