Add pod_annotations to kubernetes_logs source output log events

[aivanov-citc]

Is it possible to get annotations from the pod in kubernetes_logs and the log events similar to pod_labels?
In some cases it is convenient to use annotations.

Example:

{
  "file": "/var/log/pods/kube-system_storage-provisioner_93bde4d0-9731-4785-a80e-cd27ba8ad7c2/storage-provisioner/1.log",
  ...  
  "kubernetes.pod_labels": {
    "addonmanager.kubernetes.io/mode": "Reconcile",
    "gcp-auth-skip-secret": "true",
    "integration-test": "storage-provisioner"
  },
  "kubernetes.pod_annotations": {
    "annotation1": "sample text",
    "annotation2": "sample text",
  },
  "kubernetes.pod_name": "storage-provisioner",
  ...
  "source_type": "kubernetes_logs",
  "stream": "stderr",
  "timestamp": "2020-10-15T11:01:46.499555308Z"
}

Example using in VRL

  if .kubernetes.pod_annotations.annotation1 != null {
    ...
  }

[jszwedko]

Hi @anton-ryzhov !

Good question. It looks like Vector doesn't pick those up right now. I created this enhancement issue: #7497

[anton-ryzhov]

Hello 😂

[spencergilbert]

Supported as of #9180!