root@yoda:/# sudo -u logstash /usr/share/logstash/bin/logstash-plugin install x-pack
Downloading file: https://artifacts.elastic.co/downloads/logstash-plugins/x-pack/x-pack-6.2.2.zip
Downloading [=============================================================] 100%
Installing file: /tmp/studtmp-b95b6613b67c54d55b62eb62fb06ec56f99a00d9a688fd07c1fac326bd86/x-pack-6.2.2.zip
ERROR: Something went wrong when installing x-pack, message: Permission denied - /usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/x-pack-6.2.2-java/CHANGELOG.md