docker run -d -p 24224:24224 -p 24224:24224/udp -v /data:/fluentd/log phillu/fluentd-elasticsearch
Follow instructions on https://hub.docker.com/r/fluent/fluentd/ to run this image
I just took the elasticsearch plugin install instructions from the page above and made a docker image out of it.
Public docker image ist here: https://hub.docker.com/r/phillu/fluentd-elasticsearch/