# Changelog

All notable project changes should be documented here.

This project has not yet established a versioned changelog. Add entries as releases are published.

## Unreleased

- **Multi-stage Docker build** — the Dockerfile now compiles both the Angular frontend and Spring Boot backend inside Docker using three stages (Node.js → Gradle → JRE). Build the entire application with a single `docker build` command — no local Java or Node.js required.
- **Security hardening** — replaced full host root mount (`/:/host/root:ro`) with specific directory mounts (`/proc`, `/sys`, `/etc/hostname`, `/etc/os-release`, `/var`, `/home`, `/opt`, `/tmp`, `/srv`, `/usr`) to minimize the attack surface.
- **Host metrics consistency** — `LinuxMemoryService` and `CpuDetailsService` now read host metrics from `/host/proc` instead of container metrics from OSHI.
- **Concurrency improvements** — replaced `synchronized` methods with `AtomicReference` in `SystemMetricsService`, `SystemProcessesService`, and `CpuDetailsService` to eliminate lock contention.
- **Global error handling** — added `@RestControllerAdvice` for structured JSON error responses.
- **Unit tests** — added 32 tests covering `/proc` file parsers, CPU usage calculations, and process uptime logic.
- **Docker security** — added non-root user (`appuser`), read-only filesystem, `no-new-privileges`, and healthcheck to the container.
- **Debug logging** — added `log.debug()` calls in silent catch blocks across all services.
- **Documentation structure established.**