Motivation

Imagine handling multi-tenant services, that each require certain config contexts to be specified for using them (think db connection information for instance). A “configuration matrix” if you like. The parameters of these config options are the same, but their values differ. You are creating CLI tools for working with these services and find yourself doing:

$ some_task1(db_host=service_A_ip, db_name=service_A_name, param1, param2)
$ some_task2(db_host=service_A_ip, db_name=service_A_name)
$ some_task3(db_host=service_A_ip, db_name=service_A_name, param1)

$ some_task1(db_host=service_B_ip, db_name=service_B_name, param1, param2)
$ some_task2(db_host=service_B_ip, db_name=service_B_name)
$ some_task3(db_host=service_B_ip, db_name=service_B_name, param1)

This small library intends to help bring things back to:

$ some_task1(param1, param2)
$ some_task2()
$ some_task3(param1)

This is just an example. The tool is meant to be generic and is not nescessarily only made for this particular use case.

Operation

This tool works by providing a way to persist configuration coordinates that can be used to look up the appropriate configuration in the “configuarion matrix”. The configuration coordinates are stored in a file at well-known location (look at current dir, then traverse upwards in file hierarchy until / or ~/.config/conftext.ini).

A command-line tool, also called conftext, can be used to show and manipulate the conftext file.

Usage

Use get_config in code where context-aware config should be loaded. The conftext invoke task can then be used to switch the context config.

Example in code:

defaults = dict(
    service='dummy',
    context='local')

config = Conftext(section='package.module', default_config=defaults)

Command-line usage:

$ conftext show
$ conftext set --service <someservice>
$ conftext set --service <someservice> --context <somecontext>

Ideas

• add a enter task for the CLI tool that will enter the conf context?

  • when inside conf context, consider modifying the prompt to show vital context config

  • add exit task as well

• add python prompt with config context as well?