In order to avoid bad surprises when new (incompatible) versions of Graylog are released, we decided to remove the “latest” tag from our graylog/graylog (same as graylog2/graylog) Docker image.
If you’re using either graylog/graylog or graylog2/graylog to run Graylog in Docker (or Kubernetes), please make sure to specify at least the minor version (i. e. graylog/graylog:2.4) or the fully qualified version (i.e. graylog/graylog:2.4-3-1) of the Docker image.
Please refer to the following GitHub issue for the rationale behind that decision:
https://github.com/Graylog2/graylog-docker/issues/13