Rollout spec - K8s Validating Webhook

[rjpnps]

Summary

What change needs making?

As complementary to the closed issue about Rollout spec validation, it would be great to add support for an optional ValidatingWebhookConfiguration.

Use Cases

When would you use this?

This feature applies to Kubernetes v1.19+ clusters with the admissionregistration.k8s.io/v1 API enabled. For such clusters this approach is superior to the current alternatives:

• Reactive Approach - The informer already performs the spec validation to evolve to InvalidSpec state; Still ahead of time validation reduces MTTD.
• Proactive Approach - Use the k8s plugin to lint the spec. On the downside, this requires an additional step on any CD pipeline to render, select and lint the spec.

[github-actions]

This issue is stale because it has been open 60 days with no activity.

[github-actions]

This issue is stale because it has been open 60 days with no activity.