Is it possible to authorize users from LDAP for specific indices?
Like, that the user first have to login and then I can give him the permissions to specific repositories.
No, provided that you know the LDAP DN of the user, or the DNs of the LDAP groups to which they are a member, you can set everything up before you grant them access.
can I create groups, on which I can set the permissions
Yes, in two different ways
We have Roles that are essentially a collection of permissions to specific indices (and global cluster permissions). So, for example, there is a builtin role called
kibana_user which provides the permissions a user needs in order to have access to use the Kibana product. You then grant that role to whichever users ought to be able to use Kibana.
We also support integration with LDAP groups, so if you like, you can manage a user's groups within your LDAP directory and then map those groups to X-Pack roles if that makes management easier for you.
All our documentation is freely available, and you can install a 30 day trail of X-Pack so it might be easiest to try it out for yourself.