Add volume to point to config file and add healthcheck

Dockerfile

@@ -1,10 +1,16 @@
 FROM node:5-onbuild
-
+VOLUME /etc/statsd/
+COPY exampleConfig.js /etc/statsd/config.js
 RUN \
-  cp -v exampleConfig.js config.js && \
-  sed -i 's/graphite.example.com/graphite/' config.js
+  sed -i 's/graphite.example.com/graphite/' /etc/statsd/config.js
 
-EXPOSE 8125/udp
+EXPOSE 8125/UDP
 EXPOSE 8126
+RUN  apt-get -y update && \
+       apt-get -y install --no-install-recommends \
+       netcat=1.10-41 \
+       && apt-get clean \
+       && rm -rf /var/lib/apt/lists/*
 
-ENTRYPOINT [ "node", "stats.js", "config.js" ]
+CMD [ "node", "stats.js", "/etc/statsd/config.js" ]
+HEALTHCHECK --interval=30s --timeout=2s --retries=3 CMD  nc -vv -z -u 127.0.0.1 8125