Secret environment variable not loaded in drone 1.6.5 services syntax

Drone Support
1

Hi

I have drone 1.6.5 on top of kubernetes with drone-runner-kube:1.0.0-beta.1

I tried to create services

kind: pipeline
type: kubernetes
name: some-pipeline-name

services:
  - name: postgres
    image: postgres:9.5.4
    environment:
      POSTGRES_PASSWORD: some-password
      POSTGRES_USER: some-user
      POSTGRES_DB: some-db

That setup is worked fine.
But when I use some secret like this

kind: pipeline
type: kubernetes
name: some-pipeline-name

services:
  - name: postgres
    image: postgres:9.5.4
    environment:
      POSTGRES_PASSWORD:
        from_secret: pg_password
      POSTGRES_USER:
        from_secret: pg_user
      POSTGRES_DB: some-db

the POSTGRES_PASSWORD and POSTGRES_USER environment is not listed when I exec the postgres container with printenv.

Is a service cannot read environment variable from secret?

I also read https://docs.drone.io/pipeline/environment/syntax/. There is no documentation about service that can use environment variables. Should I use detachable steps to create service that load environment from secret like as documented in https://docs.drone.io/pipeline/kubernetes/syntax/services/ ?

Thank you