lint: remove unnecessary/noisy packages from ubuntu docker image

Author: kruskall

packaging/docker/Dockerfile

@@ -91,6 +91,10 @@ RUN mkdir --mode=0777 data
 RUN echo 'apm-server:*:1000:1000::/usr/share/apm-server:/bin/false' >> /etc/passwd
 RUN chown -R 1000:1000 /usr/share/apm-server
 
+# remove unnecessary packages
+RUN dpkg -r --force-depends libgssapi-krb5-2 libtirpc3 libnsl2 && \
+    rm /var/log/dpkg.log
+
 USER apm-server
 EXPOSE 8200
 ENTRYPOINT ["/usr/bin/tini", "--", "/usr/local/bin/docker-entrypoint"]