IRSA (IAM role for service account) is a very useful tool which permits us to provide AWS permissions to the containers in any pod that uses that service account. This enables us to give a very granular permission setting for specific service accounts and remove most of the headache related to authentication and persisting of secrets.
Below a quick snippet of how to create such mechanism.
Neat example of how we can use terraform http data source to wait for our kubernetes cluster to come up with a healthy state (shamelessly taken from some github repo)