Legacy Food‑Ordering Monolith

Purpose
A deliberately legacy PHP monolith that mimics a real‑world food‑ordering platform.
Use it to demonstrate strangler‑fig migration patterns, microservice extraction, and automated refactoring with Cascade.

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1. Architecture Overview

Browser ──► PHP 8.1 CLI server (Monolith)
                │
                ├─ MySQL 8   – persistent data (menu, orders, users)
                ├─ Redis 7   – sessions + kitchen queue

• Tech stack: plain PHP (no framework) organised in a basic MVC folder layout.
• Single deployable: all business domains live in one codebase and share a single database.

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2. Directory Structure

Path	Purpose
public/	Web root (index.php) plus CSS/JS assets
app/Controllers/	Thin HTTP controllers
app/Models/	Active‑Record style classes mapping tables
app/Views/	Templates for HTML rendering
database/migrations/	SQL files for schema setup
scripts/	Seed/utility scripts (seed_demo_data.php, send_order_emails.php)
docker/	Dockerfiles and docker-compose.yml lives in root

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3. Setup & Running Instructions

Quick-Start (Docker)

Follow this exact sequence to boot the stack from a clean slate:

# 1. Build the PHP image (installs redis ext & composer deps layer)
docker compose build

# 2. Start containers (PHP, MySQL, Redis)
docker compose up -d

# 3. Install PHP dependencies inside the running php container
docker compose exec php composer install

# 4. Run database migrations (creates tables)
docker compose exec php php scripts/setup_db.php

# 5. Open the application in your browser
open http://localhost:8080     # public menu
open http://localhost:8080/kitchen  # kitchen view

By default the app uses file-based PHP sessions (simpler during local dev). To switch to Redis-backed sessions:

1. Uncomment the Redis session.save_handler block at the top of public/index.php.
2. Ensure the redis container is running (docker compose ps).

To tear everything down and wipe DB/Redis volumes:

docker compose down -v --rmi local

4. Application Workflows & Endpoints

Action	URL/Route	Description
Browse menu	/menu	Reads menu from DB, caches in Redis, renders menu view
Add to cart	/cart/add?id=42	Adds item to cart (session, Redis-backed), shows cart view
Checkout	/checkout	Creates order, stores items, pushes to Redis queue, clears cart
Kitchen view	/kitchen	Shows queued orders (polled from Redis), kitchen staff view
Mark ready	/kitchen/ready?id=99	Marks order ready, removes from queue, triggers email via cron

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7. Project Structure & Migration Talking Points

• Hot spot: menu reads – perfect candidate for first microservice.
• Side effects: global helpers cause hidden coupling (pricing logic inside helpers.php).
• Shared DB: all domains reference the same tables, making data carve‑out a key challenge.

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7. Cleaning Up

docker compose down -v    # stops containers and removes volumes

Coverage is intentionally minimal to highlight difficulties when migrating legacy code.

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8. License

MIT – for demo and educational use.

Created June 20, 2025.