[bitnami/common] Add support for customizing standard labels

[juan131]

Description of the change

This PR makes it possible to overwrite the standard labels below that are currently set with predefined values based on chart name, chart release name, etc.

• app.kubernetes.io/name
• helm.sh/chart
• app.kubernetes.io/managed-by
• app.kubernetes.io/instance

Benefits

Users can set any desired custom value to the labels mentioned above.

Possible drawbacks

We'll have to update every single chart right away to make them compatible with new common.labels.standard and common.labels.matchLabels helpers' format.

Applicable issues

• fixes Unable to override managed-by label via commonLabels #18025

Checklist

• Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• All commits signed off and in agreement of Developer Certificate of Origin (DCO)

Additional information

Find below an example for adopting the new helper format on Apache:

diff --git a/bitnami/apache/templates/deployment.yaml b/bitnami/apache/templates/deployment.yaml
index 7fc270be8..525401805 100644
--- a/bitnami/apache/templates/deployment.yaml
+++ b/bitnami/apache/templates/deployment.yaml
@@ -8,16 +8,14 @@ kind: Deployment
 metadata:
   name: {{ include "common.names.fullname" . }}
   namespace: {{ .Release.Namespace | quote }}
-  labels: {{- include "common.labels.standard" . | nindent 4 }}
-    {{- if .Values.commonLabels }}
-    {{- include "common.tplvalues.render" ( dict "value" .Values.commonLabels "context" $ ) | nindent 4 }}
-    {{- end }}
+  labels: {{- include "common.labels.standard" ( dict "customLabels" .Values.commonLabels "context" $ ) | nindent 4 }}
   {{- if .Values.commonAnnotations }}
   annotations: {{- include "common.tplvalues.render" ( dict "value" .Values.commonAnnotations "context" $ ) | nindent 4 }}
   {{- end }}
 spec:
+  {{- $podLabels := merge .Values.podLabels .Values.commonLabels }}
   selector:
-    matchLabels: {{- include "common.labels.matchLabels" . | nindent 6 }}
+    matchLabels: {{- include "common.labels.matchLabels" ( dict "customLabels" $podLabels "context" $ ) | nindent 6 }}
   replicas: {{ .Values.replicaCount }}
   revisionHistoryLimit: {{ .Values.revisionHistoryLimit }}
   {{- if .Values.updateStrategy }}
@@ -25,10 +23,7 @@ spec:
   {{- end }}
   template:
     metadata:
-      labels: {{- include "common.labels.standard" . | nindent 8 }}
-        {{- if .Values.podLabels }}
-        {{- include "common.tplvalues.render" (dict "value" .Values.podLabels "context" $) | nindent 8 }}
-        {{- end }}
+      labels: {{- include "common.labels.standard" ( dict "customLabels" $podLabels "context" $ ) | nindent 8 }}
       {{- if or .Values.podAnnotations (and .Values.metrics.enabled .Values.metrics.podAnnotations) }}
       annotations:
         {{- if .Values.podAnnotations }}
@@ -53,8 +48,8 @@ spec:
       affinity: {{- include "common.tplvalues.render" (dict "value" .Values.affinity "context" $) | nindent 8 }}
       {{- else }}
       affinity:
-        podAffinity: {{- include "common.affinities.pods" (dict "type" .Values.podAffinityPreset "context" $) | nindent 10 }}
-        podAntiAffinity: {{- include "common.affinities.pods" (dict "type" .Values.podAntiAffinityPreset "context" $) | nindent 10 }}
+        podAffinity: {{- include "common.affinities.pods" (dict "type" .Values.podAffinityPreset "customLabels" $podLabels "context" $) | nindent 10 }}
+        podAntiAffinity: {{- include "common.affinities.pods" (dict "type" .Values.podAntiAffinityPreset "customLabels" $podLabels "context" $) | nindent 10 }}
         nodeAffinity: {{- include "common.affinities.nodes" (dict "type" .Values.nodeAffinityPreset.type "key" .Values.nodeAffinityPreset.key "values" .Values.nodeAffinityPreset.values) | nindent 10 }}
       {{- end }}
       {{- if .Values.podSecurityContext.enabled }}

Using the changes mentioned above we can customize labels as shown in the example below:

$ helm template apache bitnami/apache \
  --set 'commonLabels.app\.kubernetes\.io/instance=MainApache' \
  --set 'commonLabels.app\.kubernetes\.io/managed-by=JuanAriza' \
  --set 'commonLabels.foo=bar' \
  --set 'podLabels.foo=baz' \
  -s templates/deployment.yaml
---
# Source: apache/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  (...)
  labels:
    app.kubernetes.io/name: apache
    helm.sh/chart: apache-10.0.2
    app.kubernetes.io/instance: MainApache
    app.kubernetes.io/managed-by: JuanAriza
    foo: bar
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: apache
      app.kubernetes.io/instance: MainApache
      foo: baz
  (...)
  template:
    metadata:
      labels:
        app.kubernetes.io/name: apache
        helm.sh/chart: apache-10.0.2
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/instance: MainApache
        foo: baz
    spec:
      (...)
      affinity:
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
            - podAffinityTerm:
                labelSelector:
                  matchLabels:
                    app.kubernetes.io/name: apache
                    app.kubernetes.io/instance: MainApache
                    foo: baz
                topologyKey: kubernetes.io/hostname
              weight: 1
  (...)

[lindhe]

The code as such LGTM, as far as I can tell (just that minor typo in a comment that we should fix).

But I'd like to try this out first before approving, to confirm that it behaves as I expect.

[lindhe]

Everything seems to work as expected when I tried it out! 👍 Good work!

[dgomezleon]

LGTM

[juan131]

Hi @jouve @Qjammer

Is this sth you can fix by upgrading your Helm client version? I'm unable to reproduce it with Helm v3.12.2

[Qjammer]

We're in the process of upgrading our helm version 👍 . I will report back if the issue remains after the upgrade. Otherwise, I consider this case closed for me.

[jouve]

@juan131 I tried to reproduce @Qjammer with helm 3.5 because the prerequites in the README.md of this repo state that helm 3.2+ is supported:

    Kubernetes 1.19+
    Helm 3.2.0+

As I said in my comment , go > 1.16 should fix the issue, and helm > 3.6 are built with such versions of go.

[jouve]

I guess the multiline pipeline could be rewriten like :

{{- define "common.labels.standard" -}}
{{- if and (hasKey . "customLabels") (hasKey . "context") -}}
{{- $default := (dict) -}}
{{- $_ := set $default "app.kubernetes.io/name" (include "common.names.name" .context) -}}
{{- $_ = set $default "helm.sh/chart" (include "common.names.chart" .context) -}}
{{- $_ = set $default "app.kubernetes.io/instance" .context.Release.Name -}}
{{- $_ = set $default "app.kubernetes.io/managed-by" .context.Release.Service -}}
{{ merge (include "common.tplvalues.render" (dict "value" .customLabels "context" .context) | fromYaml) $default | toYaml }}
{{- else -}}
...