persiliao/samantha repository overview

⁠Spring Boot Application Docker Image

Production-grade, secure, lightweight Docker image for Spring Boot applications based on Liberica JDK 8/17/21 Alpine

⁠1. Image Overview

• Base Image: bellsoft/liberica-openjdk-alpine:java-version-cds
• Java Version: 8/17/21
• OS: Alpine Linux (lightweight & secure)
• Application: Spring Boot backend service
• Environment: Production ready
• Security: Non-root user, proper permissions, tini init process
• Maintainer: Persi.Liao [email protected]⁠
• License: MIT

⁠2. Key Features & Best Practices

✅ Lightweight & Stable：Alpine-based minimal footprint
✅ Production Security：Non-root user (UID 1000)，no root runtime
✅ Process Safety：tini as init process，prevents zombie processes
✅ Fast Dependency Installation：Aliyun Alpine mirror
✅ Health Check：Built-in Spring Boot Actuator health check
✅ Configurable：All JVM & runtime params via environment variables
✅ Log & Dump Directory：Pre-created /app/logs /app/heapdump with correct permissions
✅ Clean Image：No cache，minimal layers

⁠3. Directory Structure

/app/
  ├── app.jar               # Spring Boot application JAR
  ├── docker-entrypoint.sh  # Startup script
  ├── logs/                 # Application logs
  └── heapdump/             # JVM heap dump files

⁠4. Environment Variables

All variables can be overridden at runtime (docker run -e KEY=VALUE).

⁠Core Runtime

⁠5. Exposed Port

• 8080 (configurable via SERVER_PORT)

⁠6. Health Check

Auto-check every 30s：

curl -f http://127.0.0.1:8080/actuator/health || exit 1

Parameters：

• interval: 30s
• timeout: 3s
• retries: 3
• start-period: 60s

⁠7. Run Container (Recommended)

docker run -d \
  --name spring-boot-app \
  -p 8080:8080 \
  -e SPRING_PROFILES_ACTIVE=prod \
  -v $(pwd)/app.jar:/app/app.jar \
  -v $(pwd)/logs:/app/logs \
  -v $(pwd)/heapdump:/app/heapdump \
  --restart always \
  <your-image-name>:<tag>

⁠8. Security Features

• Runs as non-root user appuser (UID 1000)
• Read-only base application directory
• Log/heapdump with write-only access
• No unnecessary packages
• Clean APK cache

⁠9. Build & Maintainance

⁠Build Image

docker build -t spring-boot-app:jdk8-alpine .

⁠Check Image Info

docker inspect <image-id>
docker image inspect --format '{{.Config.Labels}}' <image-id>

⁠10. Labels

org.opencontainers.image.title=Spring Boot Application
org.opencontainers.image.description=Production-ready Spring Boot service with JDK 8 Alpine
org.opencontainers.image.version=8
org.opencontainers.image.licenses=MIT
org.opencontainers.image.base.name=bellsoft/liberica-openjdk-alpine
org.opencontainers.image.base.tag=8-cds
maintainer=Persi.Liao <[email protected]>
java.version=8
os=Alpine Linux
app=spring-boot
env=production
component=backend

⁠11. License

MIT