This project has been created as part of the 42 curriculum by khaled.

Inception

Description

Inception is a system administration project from the 42 curriculum. The goal is to set up a small infrastructure composed of different services running in Docker containers, all orchestrated with Docker Compose.

The stack includes:

• MariaDB — database server storing all WordPress data
• WordPress + PHP-FPM — the web application, running without NGINX
• NGINX — reverse proxy, the only entry point via HTTPS (port 443)

All containers are built from scratch using custom Dockerfiles based on debian:bullseye. No pre-built images are used (except the base OS).

Docker in This Project

Docker is used to isolate each service in its own container. Each container has a single responsibility, communicates with others via a private Docker network, and persists its data through named volumes.

Virtual Machines vs Docker

	Virtual Machine	Docker Container
OS	Full guest OS per VM (kernel included)	Shares host kernel
Size	GBs	MBs
Startup	Minutes	Seconds
Isolation	Full hardware virtualization	Process-level isolation
Use case	Run different OS	Run isolated services

This project runs inside a VM (as required by 42), and Docker runs inside that VM to isolate each service.

Secrets vs Environment Variables

	.env file	Docker Secrets
Purpose	Non-sensitive config	Passwords, credentials
Visible in docker inspect	✅ Yes	❌ No
Mounted in container	As env vars	As files in /run/secrets/
Examples used	DOMAIN_NAME, MYSQL_USER	db_password, db_root_password

Passwords are stored in secrets/ files and never committed to Git. The .env file only contains non-sensitive configuration.

Docker Network vs Host Network

	Docker Bridge Network	Host Network
Isolation	Containers isolated from host	Container shares host network stack
DNS	Container names resolve automatically	No built-in DNS
Security	✅ Safer	❌ Less secure
42 rule	✅ Required	❌ Forbidden

This project uses a custom bridge network named inception. Containers communicate using service names (e.g., mariadb, wordpress) — Docker resolves these automatically via its internal DNS.

Docker Volumes vs Bind Mounts

	Named Volumes	Bind Mounts
Data location	Managed by Docker	Specific host path
Subject requirement	✅ Required	❌ Forbidden for persistent data
Used for	MariaDB data, WordPress files	Not used
Path	/home/khaled/data/	—

This project uses named volumes with driver_opts to store data at /home/khaled/data/db and /home/khaled/data/wordpress on the host machine.

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Instructions

Requirements

• Docker and Docker Compose installed
• sudo access (for /etc/hosts and volume directories)
• Git

Installation

git clone https://github.com/khaled/inception.git
cd inception

Create the secrets files (never commit these):

echo "your_wp_password" > secrets/db_password.txt
echo "your_root_password" > secrets/db_root_password.txt
cat > secrets/credentials.txt << 'CREDS'
wp_admin_user=your_admin_username
wp_admin_password=your_admin_password
wp_admin_email=your@email.com
CREDS

Create the .env file:

cat > srcs/.env << 'ENV'
DOMAIN_NAME=khaled.42.fr
MYSQL_USER=wpuser
MYSQL_DATABASE=wordpress
ENV

Running the Project

# Build and start all services
make

# Stop all containers
make down

# Full reset (removes all data)
make fclean

# Full reset and rebuild
make re

Accessing the Site

Add to /etc/hosts (done automatically by make):

127.0.0.1 khaled.42.fr

• Website: https://khaled.42.fr
• Admin panel: https://khaled.42.fr/wp-admin

Note: The browser will show an SSL warning because the certificate is self-signed. Click "Advanced" → "Accept Risk and Continue".

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Resources

Documentation

• Docker official docs
• Docker Compose reference
• MariaDB Docker setup
• PHP-FPM configuration
• NGINX reverse proxy guide
• WP-CLI documentation
• OpenSSL self-signed certificates
• Docker secrets

AI Usage

AI (Claude by Anthropic) was used during this project for:

• Understanding concepts — Docker layers, PID 1, FastCGI, TLS, socket files, and the difference between volumes/bind mounts/secrets/env vars.
• Debugging — identifying why MariaDB users were not being created (volume not being cleared between runs), why mysqladmin was not found in the WordPress container, and why PHP-FPM was failing without /run/php/.
• Code explanation — understanding each line of the Dockerfiles, setup.sh scripts, nginx.conf, and docker-compose.yml before writing them.
• Architecture overview — visualizing the full request flow from browser to MariaDB and back.

All AI-generated content was reviewed, tested, and understood before being included in the project.