title: Why is "{{.Release.namespace}}" rendered empty?
body: <p>I understand that <code>{{.Release.namespace}}</code> will render the namespace where the application being installed by <code>helm</code>. In that case, <code>helm template</code> command will render it as empty string (since it doesn't know yet the release namespace). </p>
  
  <p>However, what makes me surprise is <code>helm upgrade --install</code> command (i haven't tried other command such as <code>helm install</code>) also renders it empty on some cases. </p>
  
  <p>Here is the example of my helm chart template:</p>
  
  <pre><code>apiVersion: v1
  kind: Service
  metadata:
    name: {{.Values.app.name}}-{{.Values.app.track}}-internal
    namespace: {{.Release.namespace}}
    annotations:
      testAnnotate: "{{.Release.namespace}}"
  spec:
    ports:
      - protocol: TCP
        port: 80
        targetPort: 8080
    selector:
      app: {{.Values.app.name}}
      environment: {{.Values.app.env}}
      track: {{.Values.app.track}}
    type: ClusterIP
  </code></pre>
  
  <p>After invoke <code>helm upgrade --install</code> on that chart template (and installed it successfully), I then try to see the output of my resource </p>
  
  <pre><code>&gt; kubectl get -o yaml svc java-maven-app-stable-internal -n data-devops
  apiVersion: v1
  kind: Service
  metadata:
    annotations:
      testAnnotate: ""
    creationTimestamp: 2018-08-09T06:56:41Z
    name: java-maven-app-stable-internal
    namespace: data-devops
    resourceVersion: "62906341"
    selfLink: /api/v1/namespaces/data-devops/services/java-maven-app-stable-internal
    uid: 5e888e6a-9ba1-11e8-912b-42010a9400fa
  spec:
    clusterIP: 10.32.76.208
    ports:
    - port: 80
      protocol: TCP
      targetPort: 8080
    selector:
      app: java-maven-app
      environment: stg
      track: stable
    sessionAffinity: None
    type: ClusterIP
  status:
    loadBalancer: {}
  </code></pre>
  
  <p>As you can see, I put <code>{{.Release.namespace}}</code> on 2 places:</p>
  
  <ul>
  <li>in <code>metadata.namespace</code> field</li>
  <li>in <code>metadata.annotations.testAnnotate</code> field.</li>
  </ul>
  
  <p>But it only renders the correct namespace on <code>metadata.namespace</code> field. Any idea why?</p>