[Helm] Cannot deploy on Kubernetes 1.19 because of internalTrafficPolicy

[petewall]

Request

Kubernetes Service
spec.internalTrafficPolicy was made stable in Kubernetes 1.26. This setting prevents installs on earlier cluster versions:

Error: INSTALLATION FAILED: unable to build kubernetes objects from release manifest: error validating "": error validating data: ValidationError(Service.spec): unknown field "internalTrafficPolicy" in io.k8s.api.core.v1.ServiceSpec
make: *** [deploy] Error 1

This can be fixed by adding this into the service template:

apiVersion: v1
kind: Service
...
spec:
...
  {{- if semverCompare ">=1.26-0" .Capabilities.KubeVersion.Version }}
  internalTrafficPolicy: {{.Values.alloy.service.internalTrafficPolicy}}
  {{- end }}
...

Use case

With this simple change, we could deploy on earlier cluster versions.