Legacy App Containerization & Migration

Project Context

This project was part of a university virtualization module (SAE). While the original PHP application was developed in a team of three, I took the lead on the DevOps and Infrastructure phase. The goal was to transform a “legacy” local development setup into a professional, containerized deployment compatible with private OCI registries.

Key Technical Challenges

1. Database Engine Migration

The original application was tightly coupled to MariaDB (MySQL). I managed the migration to PostgreSQL, which involved:

• SQL Refactoring: Rewriting incompatible queries and adjusting data types.
• Driver Transition: updating the PHP PDO abstraction layer to use the pgsql driver.
• Automated Seeding: Creating idempotent SQL scripts in /docker-entrypoint-initdb.d to initialize the schema automatically upon container startup.

2. Podman Pod Architecture

Instead of using standard Docker containers linked via a bridge network, I implemented a Podman Pod architecture.

• Shared Namespace: The Web and Database containers share the same network namespace (localhost), mimicking the “Sidecar” pattern often used in Kubernetes.
• Security: Only the HTTP port (8080) is exposed to the host; database traffic remains strictly internal to the Pod.

3. Custom Image Engineering

Standard Docker Hub images were insufficient for our custom MVC framework. I engineered a specific build process:

• Apache Configuration: Enabled mod_rewrite to handle the framework’s routing logic.
• Dependency Management: Bundled the install-php-extensions script locally to ensure build reproducibility even in offline or restricted network environments.

Infrastructure as Code

The entire deployment is defined via code, allowing for a single-command startup:

# Deploys the entire stack with networking pre-configured
podman pod create --name mvc-pod -p 8080:80 -p 5432:5432
podman run --pod mvc-pod -d postgres-db
podman run --pod mvc-pod -d mvc-app