update dockerfile

Signed-off-by: Peter Siegmund <developer@mars3142.org>

Dockerfile

@@ -1,4 +1,33 @@
-FROM eclipse-temurin:21-jre
-COPY target/*.jar app.jar
+FROM maven:3-eclipse-temurin-21-jammy as build
+
+# Install nodejs
+RUN apt-get update
+RUN apt-get install -y ca-certificates curl gnupg
+RUN mkdir -p /etc/apt/keyrings
+RUN curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg
+RUN echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_18.x nodistro main" | tee /etc/apt/sources.list.d/nodesource.list
+RUN apt-get update
+RUN apt-get install nodejs -y
+
+# Stop running as root at this point
+RUN useradd -m vaadin
+WORKDIR /usr/src/app/
+RUN chown vaadin:vaadin /usr/src/app/
+USER vaadin
+
+# Copy pom.xml and prefetch dependencies so a repeated build can continue from the next step with existing dependencies
+COPY --chown=vaadin pom.xml ./
+
+# Copy all needed project files to a folder
+COPY --chown=vaadin:vaadin src src
+
+# Build the production package, assuming that we validated the version before so no need for running tests again
+RUN mvn clean package -DskipTests -Pproduction --batch-mode
+
+# Running stage: the part that is used for running the application
+FROM eclipse-temurin:21-jre-jammy
+COPY --from=build /usr/src/app/target/*.jar /usr/app/app.jar
+RUN useradd -m vaadin
+USER vaadin
 EXPOSE 8080
-ENTRYPOINT ["java", "-jar", "/app.jar"]
+CMD java -jar /usr/app/app.jar