Hi Kevin,

First of all thank you very much for your support and graceful donation! You assumed correctly and the ``aarch-fedora-30`` builder is running on the new machine that you donated. However, I renamed the builder at this point, so the new one is ``aarch64-fedora-30``. Also, I have added a new CentOS7 builder, namely ``aarch64-centos-7``. You can see both of them on the builders page https://buildbot.mariadb.org/#/builders. Now, to answer your question

  1. So the jobs are running through docker, so jobs for different OS could be run on this host, right? Is it possible to also enable a CentOS7 job now?
Yes, you are right. We use docker to run the jobs and we can add more builders with different OSs.The new CentOS7 builder is up and running https://buildbot.mariadb.org/#/builders/33.
  1. As I mentioned in the unconference, we will have an OpenSource OS released soon, and we are looking for possiblities to also make it tested
    in the upstream, If the answer to the first question is True, we will have to prepare a base docker image for our OS, right?
The easiest setup would be to have a docker image of the OS. However, if that is not possible, we can discuss and come up with different other potential solutions. So, let us know when the OS is released.
  1. I saw that there is a sponsors site for buildbot: https://buildbot.mariadb.org/#/sponsor , are we able to be on that page too?
I have updated the sponsors page. However, if you have any suggestions or other requests regarding the sponsor page, let us know so that we can update it accordingly.