Simple "yum" installation of the "logstash" and "logstash-contrib" packages from the official centos7 image.
ENTRYPOINT is the logstash executable itself (running as user "logstash").
Default CMD outputs the version.
This is a very basic image, have to extend it yourself!
You probably want to ADD configuration files in "/etc/logstash/conf.d", EXPOSE relevant port(s) and override CMD with "--config /etc/logstash/conf.d/"
No "latest" tag provided, because not referencing a specific version is never a good idea...