Is it possible for you to see the Vault log in syslog for the POD?
You also need to set Vault environment variable `VAULT_ADDR=http://127.0.0.1:8200` or use `vault operator init -address=http://127.0.0.1:8200` according to this article.
https://discuss.hashicorp.com/t/vault-failed-to-start/2529/6