Dockerfile

# ─── Build Stage ─────────────────────────────────────────────────────────────
FROM maven:3.9.6-eclipse-temurin-21-alpine AS builder
WORKDIR /app

# Cache Maven dependencies by copying pom.xml first
COPY pom.xml .
RUN mvn dependency:go-offline -B

# Copy sources and package the application
COPY src ./src
RUN mvn package -DskipTests

# ─── Run Stage ───────────────────────────────────────────────────────────────
FROM eclipse-temurin:21-jre-alpine
WORKDIR /app

# Create a non-root system user and group for security
RUN addgroup -S ems && adduser -S ems -G ems
USER ems

# Copy the packaged jar from the builder stage
COPY --from=builder /app/target/employee-management-system-0.0.1-SNAPSHOT.jar app.jar

# Expose Spring Boot default port
EXPOSE 8080

# Run the Spring Boot application
ENTRYPOINT ["java", "-jar", "app.jar"]