add Dockerfile for building and running Java application with OpenJDK 17

Author: ffilardi-insight

copilot-demo/Dockerfile

@@ -1 +1,19 @@
 # Build a java application image based on openjdk 17 and run it on port 8080
+
+# Stage 1: Build the application
+FROM maven:3.9-eclipse-temurin-17 AS build
+WORKDIR /app
+COPY pom.xml .
+COPY src ./src
+RUN mvn clean package -DskipTests
+
+# Stage 2: Run the application
+FROM eclipse-temurin:17-jre
+WORKDIR /app
+COPY --from=build /app/target/*.jar app.jar
+
+# Create a non-root user and group, change ownership of /app, and switch to this user
+RUN addgroup --system javauser && adduser --system --ingroup javauser javauser && chown -R javauser:javauser /app
+USER javauser
+EXPOSE 8080
+ENTRYPOINT ["java", "-jar", "app.jar"]