Ok, second try and I will try to simplify the question.
I have single MongoDB cluster running on Kubernetes (using helm) and I want to configure it in a way that each microservice (service+pod) connecting to their own mongodb database on their has their own credentials.
One way is to create mongodb database/users /password per microservice.
Alternatively, can I use Kubernetes ServiceAccount and RBAC to abstract that from the database, so the credentials are automatically passed from the overlaying microservice to the underlying database.
thanks,
Can I create service accounts in mongo on k8s (and this applies to other services like redis/rabbit, which I have running on k8s)
Yes, you can create Service Accounts by following the steps here and here.
Setup Service Account Token by following the steps here.
Can I assign a service account rights (rw) on certain databases
Yes, create rolebinding and clusterrolebinding RBAC permissions for the Service Accounts by following the steps here.
Use this command to edit/update a Service Account:
kubectl edit serviceaccount <service account name> -n=<namespace>