AgentSkillsCN

docker

Java 21 应用程序的 Docker 容器化最佳实践。适用于创建 Dockerfile、优化镜像，或搭建容器安全防护体系时使用。

SKILL.md
--- frontmatter
name: docker
description: Docker containerization best practices for Java 21 applications. Use when creating Dockerfiles, optimizing images, or setting up container security.

Docker Containerization for Java

Multi-Stage Build (Recommended)

dockerfile
# Build stage
FROM maven:3.9.6-eclipse-temurin-21 AS build
WORKDIR /app
COPY pom.xml .
RUN mvn dependency:go-offline
COPY src ./src
RUN mvn clean package -DskipTests

# Runtime stage
FROM eclipse-temurin:21-jre-alpine
WORKDIR /app
RUN addgroup -g 1001 appgroup && adduser -D -u 1001 -G appgroup appuser
COPY --from=build /app/target/*.jar app.jar
USER appuser
EXPOSE 8080
HEALTHCHECK --interval=30s --timeout=3s CMD java -version || exit 1
ENTRYPOINT ["java", "-jar", "app.jar"]

JVM Container Options

code
-XX:+UseContainerSupport
-XX:MaxRAMPercentage=75.0
-XX:+UseG1GC

.dockerignore

code
target/
.git/
.github/
*.md
src/test/
.env
*.key
*.pem

Security Checklist

  • • Use multi-stage build (no build tools in production)
  • • Run as non-root user
  • • Use Alpine-based JRE image
  • • Scan with Trivy: trivy image --severity HIGH,CRITICAL myapp:latest
  • • Never store secrets in images
  • • Use specific version tags (not latest in production)