MeshConfig Strategy

Istio provides MeshConfig as a means of setting global configuration options: https://istio.io/latest/docs/reference/config/istio.mesh.v1alpha1/. New features are often introduced via config values here.

These are available via the techPreview field of SMCP. This means that when new configuration values are added, they default to being 'tech preview', regardless of their upstream status. It also means we have to do engineering and QE work to make them as supported fields. It would be better if work wasn't required to include new upstream features.

The Problem: Upstream Istio introduces new config values in MeshConfig that we cannot automatically support without making updates to Mesh config. "Tech Preview" should be a release note only.

Example features impacted:

• External Authorization support (receives regular customer requests - Istio 1.9)
• Request Classification (Istio 1.9)
• Default Retry Policies for VirtualServices

Considerations:

• What is Istio's future plans for the feature? (The 2022 roadmap talk mentioned moving features from MeshConfig to the main APIs)
• What is Istio's future plans for MeshConfig?
• How would this apply on a multi-tenant vs cluster-wide deployment (favour cluster wide).