<p>I am trying to configure Prometheus, which is included in the Gitlab Helm chart according to <a href="https://gitlab.com/charts/gitlab/blob/master/requirements.yaml" rel="noreferrer">https://gitlab.com/charts/gitlab/blob/master/requirements.yaml</a></p>

<p>My main issue is how to configure Prometheus, as the following <code>values.yaml</code> seems to be ignored:</p>

<pre><code>global:
  registry:
    enabled: false
  # Disabling minio still requires to disable gitlab.minio or it will complain about "A valid backups.objectStorage.config.secret is needed"
  minio:
    enabled: false
  ingress:
    configureCertmanager: false
    class: "nginx"
 ...

prometheus:
  install: true
  rbac:
    create: true
  #kubeStateMetrics:
  #  enabled: true
  nodeExporter:
    enabled: true
  #pushgateway:
  #  enabled: true

  server:
    configMapOverrideName: prometheus-config
    configPath: /etc/prometheus/conf/prometheus.yml
    persistentVolume:
      enabled: true
      accessModes:
      - ReadWriteMany
      mountPath: /etc/prometheus/conf
      # Increase afterwards, this is for my tests
      size: 2Gi

  alertmanager:
    enabled: true
    # Overriding the default configuration with the existing one
    configMapOverrideName: "alertmanager"
    configFileName: config.yml
    persistentVolume:
      enabled: true
      accessModes:
        - ReadWriteMany
      mountPath: /prometheus
      # Increase afterwards, this is for my tests
      size: 2Gi
</code></pre>

<p>Checked the link you provided and it seems you are trying to add values into values.yaml of your parent chart, where prometheus is a dependent sub-chart.</p>

<p>Specifying values at parent values.yaml file is done exactly in the same way you provided above.</p>

<p>Values for sub-chart should go into a property named exactly as the sub-chart.</p>

<pre><code>parentProp1: value
parentProp2: value
global:
  globalProp1: value
  globalProp2: value
subchart1:
  subchartProp1: value
  subchartProp2: value
</code></pre>

<p>Now in the above set of values, let's assume there is a <code>parentchart</code> and it has a sub-chart named <code>subchart1</code>. You need to understand the following points:</p>

<ul>
<li><code>parentProp1</code> and <code>parentProp2</code> can only be accessed in <code>parentchart</code> and not in <code>subchart1</code> as <code>Values.parentProp1</code> and <code>Values.parentProp2</code></li>
<li>global properties can be accessed from both parent and subchart1 as <code>Values.global.globalProp1</code></li>
<li><code>subchartProp1</code> and <code>subchartProp2</code> can be accessed as <code>Values.subchart1.subchartProp1</code> and <code>Values.subchart1.subchartProp2</code> in <code>parentchart</code></li>
<li><code>subchartProp1</code> and <code>subchartProp2</code> can be accessed as <code>Values.subchartProp1</code> and <code>Values.subchartProp2</code> in <code>subchart1</code></li>
</ul>

<p>Also please don't forget to use proper syntax of double curly-braces <code>{{ Values.xyz }}</code></p>

<p>I hope it helps. :)</p>
