Add Healthcheck on Docker (#204)

Dockerfile

@@ -49,4 +49,5 @@ COPY --from=build --chown=opengist:opengist /opengist/docker ./docker
 
 EXPOSE 6157 2222
 VOLUME /opengist
+HEALTHCHECK --interval=60s --timeout=30s --start-period=15s --retries=3 CMD curl -f http://localhost:6157/healthcheck || exit 1
 ENTRYPOINT ["./docker/entrypoint.sh"]