text: Title: EnvVarSource doc was wrong
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  **What happened**:
  
  When I tried to create a pod with env variables referencing to annotations:
  
  `spec.containers[0].env[0].valueFrom.fieldRef.fieldPath: Unsupported value: "metadata.annotations": supported values: "metadata.name", "metadata.namespace", "metadata.uid", "spec.nodeName", "spec.serviceAccountName", "status.hostIP", "status.podIP", "status.podIPs"`
  
  
  **What you expected to happen**:
  Should Proceed. As in [docs](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.18/#envvarsource-v1-core) It stated `metadata.annotations` is a valid option
  
  **How to reproduce it (as minimally and precisely as possible)**:
  
  **Anything else we need to know?**:
  
  **Environment**:
  - Kubernetes version (use `kubectl version`):
  v1.18.2
  - Cloud provider or hardware configuration:
  - OS (e.g: `cat /etc/os-release`):
  - Kernel (e.g. `uname -a`):
  - Install tools:
  - Network plugin and version (if this is a network-related bug):
  - Others:
  