Cannot locate RHN/DB.pm in @INC

I am trying to install spacewalk on CentOS 7 however i receive "Cannot locate RHN/DB.pm in @INC" error. It says compilation was aborted in spacewalk-setup line 33 which is "use RHN::DB ();". I tried installing RHN/DB with cpan however it gives me 404 error. What is RHN/DB ? It seems that it does not exist in google. What am I missing ? How do I install RHN/DB ?