apiVersion: v1
kind: Secret
metadata:
  name: name
  namespace: default

data:
  key: dGhpc19pc190aGVfc2VjcmV0

---
apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: test-secret
  namespace: default

spec:
  plugin:
    test-secret:
      user: admin
      secret: urn:k8s:secret:name:key