charts: add ingressClassName to ingress template

[ccolic]

Description

This PR updates the existing ingress chart template and adds the field "ingress.ingressClassName".
According to the kubernetes documentation, setting the ingressClassName in the annotations is deprecated: https://kubernetes.io/docs/concepts/services-networking/ingress/#deprecated-annotation

This fixes issue #1895

Changes

Added one line to the ingress chart template to template the field Values.ingress.ingressClassName if it exists

Verification

I tested the change locally by defining a simple my-values.yaml file:

ingress:
  enabled: true
  ingressClassName: nginx
  hosts:
  - host: chart-example.local
  tls:
  - secretName: chart-example-tls
    hosts:
      - chart-example.local

Using helm template I confirmed that a correct Ingress was templated:

helm template headlamp --namespace headlamp --create-namespace -f my-values.yaml .

Results in:

# Source: headlamp/templates/ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: headlamp
  labels:
    helm.sh/chart: headlamp-0.20.0
    app.kubernetes.io/name: headlamp
    app.kubernetes.io/instance: headlamp
    app.kubernetes.io/version: "0.23.1"
    app.kubernetes.io/managed-by: Helm
spec:
  ingressClassName: nginx
  tls:
    - hosts:
        - "chart-example.local"
      secretName: chart-example-tls
  rules:
    - host: "chart-example.local"
      http:
        paths:

[knrt10]

Thank you for the PR @ccolic. Can you please add the field ingressClassName in values.yaml and the docs for it in charts/headlamp/README.md. Thanks

[ccolic]

@knrt10 I have added it. I hope the comments are okay like this. I decided to also remove the deprecated annotation. I could also leave that in, but it seems duplicate for me.

[knrt10]

Thank you for the PR @ccolic.