title: How to flatten generated configMap from configMapGenerator?
body: <p>I'm trying to use Kustomize to generate ConfigMaps from files that contain key-value pairs. My <em>kustomization</em> file contains this:</p>
  
  <pre class="lang-yaml prettyprint-override"><code>configMapGenerator:
      - name: my-config
        files:
            - environment.properties
  </code></pre>
  
  <p>The environment.properties file contains this:</p>
  
  <pre><code>FIRST: 1
  SECOND: 2
  LAST: 3
  </code></pre>
  
  <p>The generated output contains this:</p>
  
  <pre class="lang-yaml prettyprint-override"><code>apiVersion: v1
  data:
    environment.properties: |
      FIRST: 1
      SECOND: 2
      LAST: 3
  kind: ConfigMap
  </code></pre>
  
  <p>How can I flatten this data structure? I'd rather have this output instead:</p>
  
  <pre class="lang-yaml prettyprint-override"><code>apiVersion: v1
  data:
    FIRST: 1
    SECOND: 2
    LAST: 3
  kind: ConfigMap
  </code></pre>