Dockerfile

# Multi-stage build for optimal image size
FROM eclipse-temurin:17-jdk-alpine AS builder

WORKDIR /build

# Copy Maven wrapper and pom.xml first (for layer caching)
COPY .mvn/ .mvn/
COPY mvnw pom.xml ./

# Download dependencies (cached layer)
RUN ./mvnw dependency:go-offline -B

# Copy source code
COPY src ./src

# Build application (skip tests in Docker build)
RUN ./mvnw clean package -DskipTests -B

# Runtime stage - minimal image
FROM eclipse-temurin:17-jre-alpine

WORKDIR /app

# Create non-root user for security
RUN addgroup -S matrikkel && adduser -S matrikkel -G matrikkel

# Copy JAR from builder stage
COPY --from=builder /build/target/*.jar app.jar

# Change ownership to non-root user
RUN chown -R matrikkel:matrikkel /app

# Switch to non-root user
USER matrikkel

# Health check (if REST API is enabled)
# HEALTHCHECK --interval=30s --timeout=3s --start-period=40s \
#   CMD wget --no-verbose --tries=1 --spider http://localhost:8080/actuator/health || exit 1

# Expose port (if REST API is enabled)
# EXPOSE 8080

# Set JVM options
ENV JAVA_OPTS="-Xmx1g -Xms256m -XX:+UseG1GC"

# Run application
ENTRYPOINT ["sh", "-c", "java $JAVA_OPTS -jar app.jar"]