Question: I have a windows server 2008 r2 domain named ITTraining.local promoted to dc and another server which is added in ITTraining domain and on which i am installing Certificate services role, but while doing i am getting the enterprise CA option greyed out, i searched and i found to do
"In order to install an Enterprise CA, you must be a member of either Enterprise Admins or Domain Admins in the forest root domain (either directly or through a group nesting)."

but i am not sure how to do this can someone please guide me

Answer: 
What you are trying to achieve is not possible without using the additional steps you are following. All the [clusters are created](https://cloudplatform.googleblog.com/2016/05/introducing-Google-Container-Engine-GKE-node-pools.html) using a default node pool named “default pool”
. Therefore, there is no option on the WUI or [flag on gcloud](https://cloud.google.com/sdk/gcloud/reference/container/clusters/create) that can be used for this. You might want to reply to Robert’s comment, your use case and feedback is important to improve Google’s products.
you have to delete default one and create your own either via terraform or any other programmatic approach.