argoproj/argo-workflows#711 super-brittle workaround

test.yaml

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  name: test
spec:
  entrypoint: main
  templates:
  - name: main
    inputs:
      artifacts:
      - name: kubectl
        http:
          url: https://storage.googleapis.com/kubernetes-release/release/v1.8.0/bin/linux/amd64/kubectl
        path: /usr/local/bin/kubectl
        mode: 755
    script:
      image: busybox
      command: [sh]
      source: |
        echo "PASSWORD=$(kubectl get secret my-secret -o jsonpath='{.data.password}' | base64 -d)"