Add Docker support and change default listening address

* Add Dockerfile
* Add docker-compose.yml
* Set default host address to null to make expressjs listen on both ipv4 and ipv6

Dockerfile

@@ -0,0 +1,33 @@
+FROM node:lts-alpine
+
+RUN apk add --no-cache curl
+
+RUN mkdir -p /usr/src/app && \
+    chown node:node /usr/src/app
+
+USER node:node
+
+WORKDIR /usr/src/app
+
+COPY --chown=node:node . .
+
+RUN npm run build
+
+# uncomment dbms client packages here
+#RUN npm install pg@8.5.1 && \
+#    npm install aws-sdk@2.842.0 && \
+#    npm install memcached@2.2.2 && \
+#    npm install mongodb@3.6.4 && \
+#    npm install ioredis@4.22.0 && \
+#    npm install rethinkdbdash@2.3.31
+
+ENV PORT=7777
+
+EXPOSE ${PORT}
+STOPSIGNAL SIGINT
+ENTRYPOINT [ "node", "server.js" ]
+
+HEALTHCHECK --interval=30s --timeout=5s --start-period=5s \
+    --retries=1 CMD curl -sS -o /dev/null localhost:${PORT} || exit 1
+
+CMD [ "npm", "start" ]