feat: Support Kustomize deployments

[DerekRoberts]

Description

While OpenShift Templates are excellent for dynamic, parameter-driven deployments (like PR environments), Kustomize has become the standard for managing structural differences between stable environments (TEST vs. PROD) without the "black box" complexity of Helm. Adding native Kustomize support would modernize the action and provide a cleaner path to GitOps for developers.

Proposed Change

Add a new optional input kustomization_path. When provided, the action will switch from "Template Mode" to "Kustomize Mode."

New Input

kustomization_path:
  description: 'Path to the directory containing kustomization.yaml'
  required: false

Execution Logic

1. If kustomization_path is set:
   • (Optional) If in Lite Mode (PR deployment):
     • Use kustomize edit to remove HorizontalPodAutoscaler or PodDisruptionBudget objects on the fly.
     • Use kustomize edit set replicas ... to enforce 1 replica.
   • Execute oc apply -k <kustomization_path>.
2. Else if file is set:
   • Continue with the existing oc process | oc apply workflow.

Impact

• Zero Breaking Changes: Existing users of OpenShift Templates are unaffected.
• Improved Lite Mode: Leverages native Kustomize editing instead of manual manifest manipulation.
• Modern Standards: Aligns the action with OCP 4.x best practices and provides a bridge for teams moving toward ArgoCD.