Add Dockerfile for containerization

Dockerfile

@@ -0,0 +1,44 @@
+# Multi-stage build for Spring Boot application
+FROM eclipse-temurin:21-jdk AS builder
+WORKDIR /app
+
+# Copy maven configuration first for better layer caching
+COPY mvnw pom.xml ./
+COPY .mvn .mvn
+
+# Download dependencies (this layer will be cached)
+RUN ./mvnw dependency:go-offline -B
+
+# Copy source files
+COPY src src
+
+# Build the application
+RUN ./mvnw package -DskipTests
+
+# Runtime stage
+FROM eclipse-temurin:21-jre-alpine
+WORKDIR /app
+
+# Create a non-root user for running the application
+RUN addgroup --system --gid 1001 appgroup && \
+    adduser --system --uid 1001 --ingroup appgroup appuser
+
+# Copy the built artifact from the builder stage
+COPY --from=builder /app/target/*.jar /app/application.jar
+
+# Set ownership and permissions
+RUN chown -R appuser:appgroup /app
+USER appuser
+
+# Configure JVM options for containers
+ENV JAVA_OPTS="-XX:+UseContainerSupport -XX:MaxRAMPercentage=75.0 -Djava.security.egd=file:/dev/./urandom"
+
+# Expose the application port
+EXPOSE 8080
+
+# Set health check using actuator endpoint
+HEALTHCHECK --interval=30s --timeout=3s --start-period=60s --retries=3 \
+  CMD wget --no-verbose --tries=1 --spider http://localhost:8080/actuator/health || exit 1
+
+# Run the application
+ENTRYPOINT ["sh", "-c", "java ${JAVA_OPTS} -jar /app/application.jar"]

README.md

@@ -9,3 +9,18 @@
 
 In this project I'm demonstrating you the most interesting features of [Backstage](https://backstage.io/) for generating app skeletons. \
 This skeleton was generated automatically from the following [template](https://github.com/piomin/backstage-templates/blob/master/templates/spring-boot-basic/template.yaml).xx
+
+// AI: ## Docker
+
+To build the Docker image:
+
+```bash
+docker build -t sample-spring-boot-app .
+```
+
+To run the container:
+
+```bash
+docker run -p 8080:8080 sample-spring-boot-app
+```
+