Dockerfile.optimized

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

# Install Maven
RUN apk add --no-cache maven

WORKDIR /app

# Copy dependency files first for better caching
COPY pom.xml .
RUN mvn dependency:go-offline -B

# Copy source code and build
COPY src src
RUN mvn clean package -DskipTests && \
    mv target/testk8s-*.jar app.jar

# Runtime stage with minimal Alpine Linux
FROM eclipse-temurin:17-jre-alpine

# Add metadata
LABEL maintainer="alf" \
      description="Spring Boot K8s ConfigMap Demo Application" \
      version="1.0.0" \
      org.opencontainers.image.source="https://github.com/alfdagos/K8S_Test"

# Create non-root user for security
RUN addgroup -g 1001 -S appuser && \
    adduser -u 1001 -S appuser -G appuser && \
    apk add --no-cache wget curl

WORKDIR /app

# Copy the jar file from builder stage
COPY --from=builder /app/app.jar .

# Create logs directory and set permissions
RUN mkdir -p /app/logs && \
    chown -R appuser:appuser /app

# Switch to non-root user
USER appuser

# Health check using actuator endpoint
HEALTHCHECK --interval=30s --timeout=10s --start-period=30s --retries=3 \
  CMD curl -f http://localhost:8080/actuator/health || exit 1

EXPOSE 8080

# Optimized JVM settings for containers
ENTRYPOINT ["java", \
    "-XX:+UseContainerSupport", \
    "-XX:MaxRAMPercentage=75.0", \
    "-XX:+UseG1GC", \
    "-XX:+UseStringDeduplication", \
    "-Djava.security.egd=file:/dev/./urandom", \
    "-jar", "app.jar"]