borca 2020.5

Lightweight task graph execution defined with pyproject.toml files.

borca

A PEP 518 compatible, explicit build orchestration ("borca", it's a stretch; I know) tool for Python. It is a simple tool that allows for the creation of an acyclic-task graph made up of custom operations that are typically using tools commonly found in a Python development stack (i.e. linting, testing, etc.). It makes no assumptions about its environment and does not attempt to modify it. Borca focuses on creating a model of a slim and extensible edition to the stock Python toolchain capabilities.

Current Condition

• Acyclic task graph generation
• Define default task
• Optionally define custom .toml file path
• Incremental builds with optional task state caching

Installation

Recommended installation is with pip:

pip install borca

Or even better, add it to the developer dependencies in your pyproject.toml file.

Example Usage

Borca actually uses borca itself, so take a look at its own pyproject.toml file and take a look at how it is structured. I generally use borca in the context of a virtual environment management tool such as poetry or flit.

$ poetry run borca test

This can get a little weird when defining a build task where you want to use something like the poetry build command (as borca does on itself) because it will create a nested virtual environment when invoking the poetry command again. While weird, this doesn't generally create any problems.

Although, this is not necessary if you wish to install borca manually.

$ borca test

General usage of the borca cli is as follows:

usage: borca [-h] [--no-hash] [--toml-path TOML_PATH] [--verbosity {0,1,2}] task-name

Python build orchestration tool.

positional arguments:
  task-name             name of the task to execute

optional arguments:
  -h, --help            show this help message and exit
  --no-hash             does not use or generate task I/O hash
  --toml-path TOML_PATH
                        specify alternate path to pyproject.toml file
  --verbosity {0,1,2}   specify verbosity 0, 1, or 2 (default 1)

Configuration

Borca uses the [tool.borca] heading in the pyproject.toml file to define configuration and the [[tool.borca.tasks]] list-like heading to define each task. The following are required and optional values for borca as well as their intended types.

[tool.borca]

• Required:
  • default_task: str (where this is the name of some defined task)

[[tool.borca.tasks]]

• Required:
  • name: str (where this is a unique name for a task in the project scope)
  • commands: List[str] (where this is a list of commands to be executed in the default shell)
• Optional:
  • depends_on: List[str] (where this is a list of other task names that this task depends on)
  • input_paths: List[str] (where this is a list of glob patterns defining the tasks input files for task caching purposes)
  • output_paths: List[str] (where this is a list of glob patterns defining the tasks output files for task caching purposes)

Note on Development Process

This is a tool I made primarily for myself; and as you can probably see from the commit history, I don't work on it very often. I work as a full-time software engineer and am getting my Master's in CS at the same time as well, so I don't find myself devoting a lot of time to side projects. That being said, feel free post issues or merge requests on GitLab. On that note, if you are seeing this on GitHub, be aware that development for this is actually done on GitLab due to its dope CI/CD features.