title: Helm - Configmap - Replace only the contents of file and not File Names
body: <p>I have defined application.properties files in a config dir. Config dir is on the below structure.</p>
  
  <pre><code>config
    application.properties
    application-test.properties
    application-dev.properties
    application-prod.properties
  </code></pre>
  
  <p>I have created a helm chart to create the configmap. Helm chart is defined as below</p>
  
  <pre><code>apiVersion: v1
  kind: ConfigMap
  metadata:
    name: nginx-configmap
  data:
    {{- (.Files.Glob "config/*").AsConfig | nindent 2 }}
  </code></pre>
  
  <p>I see that the configmap is created. </p>
  
  <p>We are consuming the ConfigMap via environment variables in a running container using the <code>envFrom</code> property. (This in my deployment yaml file)</p>
  
  <pre><code>spec:
     containers:
     - envFrom:
       - configMapRef:
           name: nginx-configmap
  </code></pre>
  
  <p>I see that the values are stored as environment variables. However the variables are in lower cases. </p>
  
  <pre><code>server.port=8080
  server.name=localhost
  </code></pre>
  
  <p>Since these are env variables, they have to be uppercase and . should be replaced with _. So, I have modifed my chart as below</p>
  
  <pre><code>data:
    {{- (.Files.Glob "config/*").AsConfig | nindent 2 | upper | replace "." "_" }}
  
  </code></pre>
  
  <p>The generated configmap is as below</p>
  
  <pre><code>  APPLICATION_PROPERTIES: |
      SERVER_PORT = 8080
      SERVER_NAME = LOCALHOST
  </code></pre>
  
  <p>Below is the env variables inside container</p>
  
  <pre><code>APPLICATION_PROPERTIES=SERVER_PORT = 8080
  SERVER_NAME = LOCALHOST
  </code></pre>
  
  <p>My requirement is that only the contents of the file should be upper case and . should be replaced with _.  The filename should not be converted. The filename should be as is.</p>
  
  <p>Can this be achieved? </p>