add Dockerfile

Dockerfile

+FROM ubuntu:bionic
+
+ENV DEBIAN_FRONTEND noninteractive
+ENV HOME /home/user
+RUN useradd --create-home --home-dir $HOME user \
+    && chmod -R u+rwx $HOME \
+    && chown -R user:user $HOME
+
+RUN apt-get update -y \
+    && apt-get upgrade -y \
+    && apt-get install -y --no-install-recommends openjdk-8-jdk \
+    && apt-get clean
+
+COPY --chown=user:user . /ros2rag/
+
+USER user
+WORKDIR /ros2rag
+
+RUN ./gradlew --no-daemon installDist
+
+ENTRYPOINT /bin/bash -c "./ros2rag.starter/build/install/ros2rag.starter/bin/ros2rag.starter ./ros2rag.starter/src/main/resources/config.json"
+