Helm: override values from dependency chart - kubernetes-helm

Question

I'm using a chart it's using other chart as dependency.
Its chart.yaml file is:
annotations:
category: Infrastructure
apiVersion: v2
appVersion: 3.7.0
dependencies:
- name: common
repository: https://charts.bitnami.com/bitnami
tags:
- bitnami-common
version: 1.x.x
...
It's using this dependecy into its templates like:
apiVersion: v1
kind: Service
metadata:
...
labels: {{- include "common.labels.standard" . | nindent 4 }}
app.kubernetes.io/component: zookeeper
{{- if .Values.commonLabels }}
{{- include "common.tplvalues.render" ( dict "value" .Values.commonLabels "context" $ ) | nindent 4 }}
{{- end }}
...
As you can see it's using:
labels: {{- include "common.labels.standard" . | nindent 4 }}
How can I override those values inherited from common.

Answer 1

The Bitnami Common Library Chart is a library chart: it doesn't provide any Kubernetes resources of its own, just a library of template functions you can call (with include or template). That also means it doesn't have its own set of values in the way Helm dependency charts normally do; it uses whatever .Values are in the object you pass to the template.
The implementation of common.labels.standard is pretty straightforward; it provides a set of standard labels that almost every chart should have. You don't usually need to edit these, and you can't change their outputs without copying and pasting the template contents.
Note that one consequence of this is that, if you have a parent chart and a subchart that both include "common.labels.standard" ., they will get different values. .Release.Name will be the same for both, but .Chart.Name will depend on the specific chart being installed (parent or dependency), and in the subchart, .Values will be narrowed to that subchart's settings in the top-level values.
If you need to add labels, this change is easy, and you demonstrate it above. Helm's general operation is to run the template engine naïvely to produce a text document, then hope it's a valid YAML file. If you want additional labels, just include them in the template.
metadata:
labels:
{{-/* the generated labels from the Common chart */}}
{{- include "common.labels.standard" . | indent 4 }}
{{-/* and then any additional labels (correctly indented) */}}
example.com/additional-label: is-present