Improve Dockerfile and change the default port

Dockerfile

@@ -1,9 +1,24 @@
 FROM node:11.14.0-stretch
 
-COPY . /home/app
+ARG UID=1000
+ARG GID=1000
 
-WORKDIR /home/app
+ENV APP_HOME=/home/app
 
+# Create group "app" and user "app".
+RUN useradd --system --create-home --home ${APP_HOME} --shell /sbin/nologin --no-log-init app
+
+WORKDIR $APP_HOME
+USER app
+
+COPY --chown=app:app package.json package-lock.json $APP_HOME/
+
+# Install dependencies
 RUN npm i
 
+# Copy the main application.
+COPY --chown=app:app . $APP_HOME
+
+EXPOSE 8081
+
 CMD ["npm","run","start"]

config/config.json

@@ -3,7 +3,7 @@
       "config_id": "development",
       "app_name": "Nodelogic",
       "app_desc": "Node JS Applogic for Rubykube Stack",
-      "node_port": 3001,
+      "node_port": 8081,
       "json_indentation": 4,
       "barong_url": "http://localhost:3000/api/v2/management/users/get",
       "jwt": {