the way to install a cluster is by installing "ha-cluster-bootstrap".
(Even Clusterlabs points to that at http://clusterlabs.org/quickstart-suse.html)
This installs a ton of packages, including gtk.

I would like to install the cluster without installing a graphical environment on the server.
The config is supposed to be deployed with ansible later anyway.
To manage the server crmsh is enough.

Is there any documentation what to install and configure for this?

(The official SUSE docs are very poor. It is only how to click )

I think I will install crmsh, pacemaker and corosync for start.

Any advice?