Dockerfile

# ── Build stage ────────────────────────────────────────────────────────────────
FROM maven:3.9-eclipse-temurin-21 AS builder
WORKDIR /app

# Cache dependency layer: copy descriptor first, then source
COPY pom.xml .
RUN mvn dependency:go-offline -q

COPY src ./src
RUN mvn package -DskipTests -q

# ── Runtime stage ───────────────────────────────────────────────────────────────
FROM eclipse-temurin:21-jre-alpine
RUN addgroup -S app && adduser -S app -G app
WORKDIR /app

COPY --from=builder /app/target/*.jar app.jar
RUN chown app:app app.jar

USER app
EXPOSE 8080

HEALTHCHECK --interval=30s --timeout=5s --start-period=40s --retries=3 \
  CMD wget -qO- http://localhost:8080/actuator/health || exit 1

ENTRYPOINT ["java", "-jar", "app.jar"]