describeme/hypergrowth

A Skeleton Project to Get going with an expandable CLI utility

What is this?

This project is a skeleton framework for building advanced command line utilities. It was developed so that it can grow with usage. For example, you would typically start off with some lightweight utilities for automating the manual operations in your environment. As your main project grows, your utilities project will also grow to automate more operations within your environment. Which is why, a manageable layout is helpful.

The interface was kept separated, so that we have flexibility with distribution. In that, a separate client can be implemented with the same interface and documentation, which may invoke the main project through a lambda function, or lambda via api-gateway.

How does it work?

The project is distributed in a typical MVC layout. The View in this case would be the Command Line Interface, while you use the Model/Controller structure to organize your code based on what they do. The layout explained:

Layout

hypergrowth

• framework - This contains implementation to route the interface to the controller

example

• model - Data structures that represents the concepts that you're working with
• repo - Implement Singletons for interacting with external datasets
• resources - Any declarative configuration files used in the project
• service - Reusable service class that perform the real work, in a parameterized way. Should not store data in these classes.
• controller - Handle the arguments passed in from the command line interface
• error - Define custom Exceptions here
• entrypoint.py - The default entrypoint script.
• tests - Unit tests for the project

example_shared

This project you will share among all your projects. So that they can all inherit the same Command line interface, even though, execution may be different. In that, your first project would execute directly, whereas, your distributed project may execute through a lambda or api-gateway interface

• interface - The command line interface that the user would interact with

Entrypoint

The Entrypoint is a module inside the example directory entrypoint.py. It sets up the main command line interface object. It then loads interfaces defined in example.interface and consolidates them as sub-commands.

Setup

The command name can be define here. Currently, it's set to doit as shown in the code segment below:

entry_points = '''
        [console_scripts]
        hg=example.entrypoint:cli
    '''

Interface

The interface section is meant to define your interface, with associated documentation, without actually executing the intended process or logic. This will go into a matching Controller The reason for this, is so that the interface can be used for multiple projects, where you want the execution to be handled differently.

example.interface.interface_one demonstrates how to setup your interface. The interface is implemented using click Click provides a clean way to implement the command line interface, including options, and nested commands.

The following is an example for setting up the interface.

import click

from hypergrowth import Configuration


@click.group()
def cli():
    pass


Configuration(
    controllers="example.controller",
    interfaces="example.interface",
    main_command_group=cli

)

Controller

The controller is the start for your implementation logic. Small commands can be fully implemented in the Controller. Larger processes with reusable parts should be defined as reusable services.

An example controller to handle the above interface, will look like the following:

from hypergrowth.framework import Component


class OneController(Component):

    def do_stuff(self, name, count):
        print(f"doing it {name} {count}")

Notice that the Name of the controller OneController matches the name of the interface group one. And the method that handles the command, do_stuff also matches the command definition do_stuff under the @one.command()

Usage

• activate your python venv python3 -m venv path-to-env; source path-to-env/bin/activate
• install the framework with examples: pip3 install hypergrowth
• Test the example command hgex one do-stuff jump. This should print doing it jump 1
• Follow the example and example_shared examples structure in the github project, to implement your own project
• Optionally, activate shell for auto-completion

Additional Notes

Autocompletion for Big Sur zsh shell

Auto completion for the zsh shell doesn't work right of the bat. The easiest way for me to get this working, was to install zsh-completion via brew info zsh-completions Then adding the following to .zshrc

if type brew &>/dev/null; then
    FPATH=$(brew --prefix)/share/zsh-completions:$FPATH

    autoload -Uz compinit
    compinit
fi

#HG and hg is based on your configuration in the setup.py
eval "$(_HGEX_COMPLETE=source_zsh hgex)"