There are some methods natively supported such as basic auth , X509 certificates and webhook tokens.
Is there some workaround/project to use LDAP for user authentication with Kubernetes. I need users to be grouped in LDAP , and then use role binding to bind the group to a specific namespace with a role.
Yes you can integrate with LDAP, for example:
Also, there's a nice intro-level blog post to get you started.