title: LabelSelector for Secrets List in k8s
body: <p>I want to get Secret object from k8s cluster using go-client API</p>
  
  <p>I have function that looks like that</p>
  
  <pre><code>func GetSecret( version string) (retVal interface{}, err error){
      clientset := GetClientOutOfCluster()
      labelSelector := metav1.LabelSelector{MatchLabels: map[string]string{"version":version}}
  
      listOptions := metav1.ListOptions{
          LabelSelector: labelSelector.String(),
          Limit:         100,
      }
      secretList, err := clientset.CoreV1().Secrets("namespace").List( listOptions )
      retVal = secretList.Items[0]
      return retVal, err
  }
  </code></pre>
  
  <p>GetClientOutOfCluster is basically retrieves configuration from cluster or from local ~/.kube/config</p>
  
  <p>I used metav1.LabelSelector just like i do when i generate new Deployment object.So i thought i was cool. But ListOptions.LabelSelector is a string.
  When i run my function it fails.</p>
  
  <pre><code>unable to parse requirement: invalid label key "&amp;LabelSelector{MatchLabels:map[string]string{version:": name part must consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyName',  or 'my.name',  or '123-abc', regex used for validation is '([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9]')
  </code></pre>
  
  <p>I cannot find example of usage of this function anywhere. Documentation assumes that you know what is LabelSelector.</p>
  
  <p>What is format of LabelSelector for ListOptions?</p>
  
  <p>Thanks</p>