Inconsistent PodDisruptionBudget API Versions Prevent Installation on Older Kubernetes Clusters

[dadrake3]

There is inconsistent handling of apiVersion for PodDisruptionBudget templates preventing installation on older Kubernetes clusters.

There are two different ways apiVersion is being set in the templates:

1 Helper Method

apiVersion: {{ include "loki.pdb.apiVersion" . }}

Used in:

templates/overrides-exporter/poddisruptionbudget-overrides-exporter.yaml
templates/chunks-cache/poddisruptionbudget-chunks-cache.yaml
templates/ingester/poddisruptionbudget-ingester.yaml
templates/ingester/poddisruptionbudget-ingester-rollout.yaml
templates/querier/poddisruptionbudget-querier.yaml
templates/bloom-builder/poddisruptionbudget-bloom-builder.yaml
templates/ruler/poddisruptionbudget-ruler.yaml
templates/distributor/poddisruptionbudget-distributor.yaml
templates/query-scheduler/poddisruptionbudget-query-scheduler.yaml
templates/query-frontend/poddisruptionbudget-query-frontend.yaml
templates/index-gateway/poddisruptionbudget-index-gateway.yaml
templates/results-cache/poddisruptionbudget-results-cache.yaml

2 Hardcode

yamlCopyapiVersion: policy/v1

Used in:

templates/backend/poddisruptionbudget-backend.yaml
templates/gateway/poddisruptionbudget-gateway.yaml
templates/read/poddisruptionbudget-read.yaml
templates/single-binary/pdb.yaml
templates/write/poddisruptionbudget-write.yaml

This is causing the kubeVersionOverride value to only affect the templates that use the helper method while the hardcoded method fails on older clusters. Specifically this happens when using scalable mode or when specifying a pdb in single binary mode.

[dadrake3]

I can open I PR to add the helper method to where its being hardcoded