unrot.app

Backend API for unrot — a curated content feed that makes people smarter, not dumber. Think Instagram-style feed, but with substance over slop.

Tech Stack

• Runtime: Java 21 LTS (Eclipse Temurin)
• Framework: Spring Boot 4.0.2, Spring Data JPA, Spring Actuator
• Language: Kotlin 2.2.21
• Database: PostgreSQL 17
• Build: Gradle 9.3
• Container: Docker (multi-stage build)
• Orchestration: microk8s with HPA autoscaling

Running Locally

Docker Compose (recommended)

docker compose up --build

App: http://localhost:8080 Health: http://localhost:8080/actuator/health

Gradle (dev)

# Start PostgreSQL
docker compose up postgres

# Run the app
./gradlew bootRun --args='--spring.profiles.active=dev'

Testing

./gradlew test

Tests use H2 in-memory database — no PostgreSQL required.

Deploy to microk8s

# Enable required addons
microk8s enable dns storage registry metrics-server

# Build and push image
docker build -t localhost:32000/demo-app:latest .
docker push localhost:32000/demo-app:latest

# Apply manifests
microk8s kubectl apply -f k8s/

# Verify
microk8s kubectl get pods -n demo
microk8s kubectl get hpa -n demo

Kubernetes Features

• Health Probes: liveness, readiness, and startup probes via Spring Actuator
• Autoscaling: HPA with 2–8 replicas, targeting 70% CPU utilization
• Secrets: DB credentials managed via Kubernetes Secrets
• Persistent Storage: PostgreSQL data on PVC (1Gi)

Spring Profiles

Profile	Usage	Database
(default)	Local development	PostgreSQL on localhost:5432
dev	Docker Compose	PostgreSQL with ddl-auto: update
prod	Kubernetes	PostgreSQL via env vars, ddl-auto: validate
test	Tests	H2 in-memory

Project Structure

├── src/main/kotlin/com/example/app/   # Application source
├── src/main/resources/                 # Config (application*.yml)
├── src/test/                           # Tests
├── k8s/                                # Kubernetes manifests
├── Dockerfile                          # Multi-stage build
└── docker-compose.yml                  # Local dev environment