This is by no means an official statement, just an observation as I’ve seen more and more posts on here leveraging CentOS 8. Also, I am not overly familiar with CentOS 8 and the changes Red Hat has made to RHEL 8, so I’m sure some of you are better equipped to head down this path.
And, while I don’t know Graylog’s official stance on it, I did want to point out a couple of things.
Graylog relies on MongoDB, Java 8 or 11 (starting with 3.x) and Elasticsearch.
Current/Latest system requirements for Graylog are listed here:
http://docs.graylog.org/en/3.2/pages/installation.html#system-requirements
MongoDB: 3.6 and 4.0, 4.2 is supported if run in 4.0 mode.
Elasticsearch 5.x and 6.x
Java 8 and 11
With these requirements, there are a couple of things to keep in mind.
MongoDB’s site states that it supports CentOS 8 starting with release 4.2.1
https://docs.mongodb.com/manual/tutorial/install-mongodb-on-red-hat/#platform-support
Elasticsearch still doesn’t list support for CentOS 8 on their site.
https://www.elastic.co/support/matrix
Graylog does not support Elasticsearch 7, and Elasticsearch 6 is end of maintenance, so the chances of them officially supporting CentOS 8 on Elasticsearch 6 are slim. 6.8 is slated for end of maintenance until November 2020.
So… tl;dr
if you are running CentOS 8, plan your build and realize that you may not get support or find answers to weird issues that pop up.