go言語 yaml からマップへの変換、マップトラバーサルの実装

apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
  name: mysql-snapshot
spec: 
  privileged: false
  allowPrivilegeEscalation: false
  volumes:
  - "*"
  hostNetwork: false
  hostIPC: false
  hostPID: false
  runAsUser:
    rule: RunAsAny
  seLinux:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  fsGroup:
    rule: RunAsAny

func main() {
f, err := os.Open("cmd/test.yaml")
 if err ! = nil {
  log.Fatalln(err)
  return
 }

 input, _ := ioutil.ReadAll(f)
 // base64 encoding
 encodeString := base64.StdEncoding.EncodeToString(input)
fmt.Println(encodeString)


// base64 decode
 DecodeBytes, err := base64.
 if err ! = nil {
  log.Fatalln(err)
 }

//yaml file content into map[interface{}]interface{})

 resultMap := make(map[interface{}]interface{})
 if err := yaml.Unmarshal(decodeBytes, &resultMap); err ! = nil {
  // error handling
  log.Fatalln(err)

 }

// Iterate over the map, here taking the metadata.name value
 for key, value := range resultMap {
  switch key := key.(type) {
  case string:
   if key == "metadata" {
    switch value := value.(type) {
    case string:
    case map[interface{}]interface{}:
     for k, v := range value {
      switch k.(type) {
      case string:
        if k == "name" {
         fmt.Println("value=", v)
        }
      }
     }

    }

   }
  }
 }
}