one-aalam / microcosm

🦄 Micro Cosmos of Microservices aspiring to be seen as a well-ordered whole

MICRO.COSM

A very minimal micro-service monorepo

Table of Contents

• Introduction
• Tech Stack
• Install
• Usage
• Lerna Quick-Reference

Introduction

A very minimal micro-service monorepo

The project has 3 packages (inside packages directory)

• micro-one (http server - based on Micro)
• micro-two (http server - based on Micro)
• micro-three (http server - based on Express)

Techstack

• Lerna - A tool for managing JavaScript projects with multiple packages
• Micro - Asynchronous HTTP microservices or,
• Express - 'Coz everybody uses it
• Jest - Jest is a delightful JavaScript Testing Framework with a focus on simplicity
• Supertest - High-level abstraction for testing HTTP, while still allowing you to drop down to the lower-level API provided by it

Design Principles

The list of community contributed modules used in the micros is kept at minimum. I tried to keep it that way to show the power of the approach and, of course, the language itself.

Data/Domain Models

Search/Discover, Order, Delivery, Payment/Checkout, Restautaurant

Install

Checkout the repo and run

lerna bootstrap

in the project's directory

That's it 🚀.

You'll find the dependenices installed and resolved now

lerna needs to be available globally for this

Usage

Go to the root of the project and run

lerna run start

That's it 🚀.

You'll find the services available on their respective ports. Visit the respective ports and see `em in action.

lerna suppresses log output of npm scripts by defualt. To allow for that, run the above script with --stream flag

Jest

Reasons to use Jest

• Jest is easy to setup
• The watch-mode is amazing
• When you console.log something, it actually shows up without any difficulty (this is a bit tricky with many existing Frameworks ).

Lerna Quick-Reference

Since most of the micros will share some common characterstics and behavior, Lerna is levaraged to manage community and cross-micro depenedencies so that it's DRY and less boring DX for ya!

Here are few of the commands you may find yourselves looking up quite often

# Adds the module-1 package to the packages in the 'prefix-' prefixed folders
lerna add module-1 packages/prefix-*

# Install module-1 to module-2
lerna add module-1 --scope=module-2

# Install module-1 to module-2 in devDependencies
lerna add module-1 --scope=module-2 --dev

# Install module-1 to module-2 in peerDependencies
lerna add module-1 --scope=module-2 --peer

# Install module-1 in all modules except module-1
lerna add module-1

# Install babel-core in all modules
lerna add babel-core

Visit https://github.com/lerna/lerna for more..