Dockerfile.java-service

# ============================================================
# Spring Boot Java 服务 Dockerfile 模板 (生产运行时)
# 适用: 预构建 JAR 由 CI 传入，服务器只负责运行
# 来源: code-craft (×4) + lumina-rpc (×5) 共 9 个文件合并
#
# 使用方式:
#   1. 复制本文件到项目根目录并重命名，如 Dockerfile.prod-user
#   2. 替换下方所有 <占位符> 为实际值
#   3. CI 中: COPY your-service.jar app.jar → docker build
# ============================================================

FROM eclipse-temurin:21-jre-alpine

WORKDIR /app

# --- [必改] 非root用户 ---
# 建议与项目名保持一致，方便日志排查
RUN addgroup -S <app-user> && adduser -S <app-user> -G <app-user>

# --- [可选] 创建日志/配置目录 ---
RUN mkdir -p /logs /app/config && \
    chown -R <app-user>:<app-user> /app /logs

USER <app-user>:<app-user>

# --- [必改] 复制构建产物 ---
# CI 流水线中先将 JAR 复制到根目录再构建镜像
COPY <your-service>.jar app.jar

# --- [必改] JVM 参数 ---
ENV JAVA_OPTS="-Xmx512m -Xms256m -XX:+UseG1GC -XX:+ExitOnOutOfMemoryError"

# --- [可选] Spring / 业务环境变量 ---
# 根据项目需要增减，所有值都支持 docker run -e 或 .env 覆盖
ENV SPRING_PROFILES_ACTIVE=docker
# ENV DB_HOST=mysql
# ENV DB_PORT=3306
# ENV REDIS_HOST=redis
# ENV REDIS_PORT=6379
# ENV NACOS_HOST=nacos
# ENV NACOS_PORT=8848

# --- [必改] 暴露端口 ---
EXPOSE <port>

# --- [推荐] 健康检查 ---
# Spring Boot Actuator: /api/actuator/health 或 /actuator/health
# 非Spring项目: 替换为 curl/wget 实际健康端点
HEALTHCHECK --interval=30s --timeout=10s --start-period=60s --retries=3 \
  CMD wget --no-verbose --tries=1 --spider http://localhost:<port>/actuator/health || exit 1

# --- 启动 ---
ENTRYPOINT ["sh", "-c", "java ${JAVA_OPTS} -jar app.jar"]