# Kubernetes auth method — workloads authenticate using their pod service account token.
resource "vault_auth_backend" "kubernetes" {
  type = "kubernetes"
  path = "kubernetes"
}

resource "vault_kubernetes_auth_backend_config" "kubernetes" {
  backend         = vault_auth_backend.kubernetes.path
  kubernetes_host = var.k8s_host
  # Vault reads the cluster CA and its own service account token from the pod
  # filesystem automatically when running inside the cluster. No explicit
  # token_reviewer_jwt or kubernetes_ca_cert needed.
  disable_iss_validation = true
}

# cert-manager role
# Bound to cert-manager's service account; grants the cert-manager policy
# so it can sign certificates via pki_int.
resource "vault_kubernetes_auth_backend_role" "cert_manager" {
  backend                          = vault_auth_backend.kubernetes.path
  role_name                        = "cert-manager"
  bound_service_account_names      = ["cert-manager"]
  bound_service_account_namespaces = ["cert-manager"]
  token_policies                   = [vault_policy.cert_manager.name]
  token_ttl                        = 3600
  token_max_ttl                    = 3600
}