title: Override config map file in helm
body: <p>We have helm charts to deploy our application. We use a <code>configuration.json</code> file for application properties and load them to config map. But users typically use their own configuration file. </p>
  
  <p>Default configuration.json file is packaged inside helm charts under data directoty. This file is read as </p>
  
  <pre><code>apiVersion: v1
  kind: ConfigMap
  metadata:
    name: app-config
  data:
  {{ (.Files.Glob .Values.appConfigFile).AsConfig | indent 4}}
  </code></pre>
  
  <p>And in values</p>
  
  <pre><code>appConfigFile: data/configuration.json
  </code></pre>
  
  <p>If users install our charts directly from repository how can this configuration file be overriden? doing <code>--set appConfigFile=/path/to/custom.json</code> doen't populate config map.</p>
  
  <p>If charts are untarred to a directory they can add the custom configuration file into charts directory and give the configuration file using <code>--set appConfigFile=customData/custom.json</code> works </p>
  
  <p>Can file overrides be achieved when charts are deployed from repository directly?</p>