Vault on k8s pre install work

I have installed on k8s Vault with https certificates.
But, before I install Vault I must prepare a configuration for install: key, csr, run kubectl command. I’m looking way to automation of this pice of config.
I see that is i helm chart a object extraInitContainers but how to use them to create proper csr on k8s, after that sign them by k8s and finally create a secret with key,cert and ca for Vault. I searched a lot of document for any advise but there is only information about run command manually.

Thanks in advance.