Enable Private Key Creds from Vault

[ericnesschrw]

Feature Request

My company is using PKI certificates generated by Vault for some credentials. These credentials require a POST call to their endpoint to generate a certificate. I've created an appropriate .teller.yaml file to pull the secret.

providers:
  hashicorp_vault:
    env_sync:
      path: pki-internal/issue/credential_name

Running teller show raises the error:

Error making API request.\n\nURL: GET https://vault_host/v1/pki-internal/issue/credential_name\nCode: 403. Errors:\n\n* 1 error occurred:\n\t* permission denied\n\n"

because teller is using GET to try to retrieve the secret.

In the research that I've done, I haven't found any way to configure Teller to POST instead of GET. It would be nice to be able to use Teller to get PKI credentials.