Minimal command-line interface using a plugin-based architecture

This project demonstrates a minimal (but featureful) command-line interface (CLI) using a plugin-based architecture (PBA). The CLI itself is constructed using Typer.

The PBA is achieved using a combination of:

• pipx
• importlib
• packaging
• Libraries.io

For a working plugin example, see minimal-pba-cli-plugin-example.

Installation

Install the core CLI using the following command:

$ pipx install minimal-pba-cli

Usage

List available commands using the help:

$ pba-cli --help

Plugins

List available plugins using the following command (requires a Libraries.io API key):

LIBRARIES_IO_API_KEY=<your API key> pba-cli plugin catalog

Install a plugin using the following command:

$ pba-cli plugin install <plugin name>

List installed plugins using the following command:

$ pba-cli plugin list

Install a plugin from a local directory using the following command:

$ pba-cli plugin install-local <path to plugin directory>

Uninstall a plugin using the following command:

$ pba-cli plugin uninstall <plugin name>

Custom scripts

To create a custom script that registers in the CLI, create an executable anywhere on your PATH that follows the naming convention minimal-pba-cli-<name>. This script will be registered as a command named <name> in the CLI.

As an example, create a script named minimal-pba-cli-hello with the following content:

#!/usr/bin/env sh

echo "Hello, world!"

Make the script executable:

$ chmod +x minimal-pba-cli-hello

Now, if the script is located in a directory on your PATH, you can run it using the following command:

$ pba-cli hello
Hello, world!

Scripts can be written in any language, as long as they are executable and follow the naming convention:

#!/usr/bin/env python

# minimal-pba-cli-quote

import json
import urllib.request


if __name__ == "__main__":
    response = urllib.request.urlopen("https://zenquotes.io/api/random")
    data = json.loads(response.read().decode("utf-8"))
    print(f"""
"{data[0]['q']}"

- {data[0]['a']}
""")

$ pba-cli quote

"Educating the mind without educating the heart is no education at all."

- Aristotle