option:   option.SubZone("fake"),
			expected: "fake",
		},
		{
			testName: "node metadata nil",
			key:      "meta_json_str",
			option:   option.NodeMetadata(nil, nil),
			expected: nil,
		},
		{
			testName: "node metadata",
			key:      "meta_json_str",
			option: option.NodeMetadata(&model.BootstrapNodeMetadata{
				NodeMetadata: model.NodeMetadata{
					IstioVersion: "fake",
				},

      {{- end }}
      {{- if .sub_zone }}
      {{- if or .region .zone }}
      ,
      {{- end }}
      "sub_zone": "{{ .sub_zone }}"
      {{- end }}
    },
    "metadata": {{ .meta_json_str }}
  },
  "layered_runtime": {
      "layers": [
          {
            "name": "global config",
            "static_layer": {{ .runtime_flags }}
          },
          {
              "name": "admin",