What are the steps for knox and ranger setup at a high level?
Do i need to enable Kerberos authentication first ?
Can everything be done via ambari ?
Quick answers to your questions
1.What are the steps for knox and ranger setup at a high level?
See official document for Ranger Installation using Ambari
For knox use Ambari UI and the steps are quite easy and straight forward. You will need to do some post setup for Ranger Plugins and Knox
2. Do I need to enable Kerberos authentication first ?
NO kerberos can be enabled before or after the setup of Ranger and Knox, any component installed after kerberization Ambari will automatically generate the principals and keytabs.
3. Can everything be done via ambari ?
Yes the Ranger/knox setup and kerberization can be done through Ambari but before you kerberize your cluster you MUST have created a KDC server and have the master password and principal at hand as these are inputs the Ambari UI will request
Hope that helps