http://docs.graylog.org/en/3.0/pages/installation/docker.html
$ docker run --name mongo -d mongo:3
$ docker run --name elasticsearch \
-e "http.host=0.0.0.0" \
-e "ES_JAVA_OPTS=-Xms512m -Xmx512m" \
-d docker.elastic.co/elasticsearch/elasticsearch-oss:6.5.4
$ docker run --link mongo --link elasticsearch \
-p 9000:9000 -p 12201:12201 -p 514:514 \
-e GRAYLOG_HTTP_BIND_ADDRESS="127.0.0.1:9000" \
-d graylog/graylog:3.0
Then http://localhost:9000/ - 404.
Should it be working out of box?