The majority of OpenShift Service Mesh doc is related to administration - installing, configuring and managing the Istio control plane for different uses cases. These are typically done by a cluster admin. From a user perspective (a dev, app admin), OpenShift Service Mesh is Istio, and thus the community documentation is mostly applicable, meaning there is less of an imperative for OSSM to document "how to use Istio".

That said, we'd like to do better than "Go find it in the community docs", which are mostly written by community member developers (not users) of Istio, and focus on documenting features and APIs rather than use cases. Our product docs should offer high level guidance and examples on the most common use cases for Istio, such as:

• Security
  • Encrypting network traffic with mTLS
    • Internal mesh service to service auth - PeerAuth / DR, etc.
    • External mesh (Gateways) cert config
  • Request authentication with JWT
  • Authorization Policies for fine grain control
• Observability (What Istio & Kiali provides):
  • Audit logging capabilities
  • What metrics are provided by Istio 
  • What is provided by distributed tracing, what is not
• Traffic Management
  • How VS / DR work to manage versions of services
  • BG / Canary deployments & A/B testing with Istio
• Service Resilience
  • Timeouts, Retries and circuit breakers (outlier detection)

The above is roughly in priority order (With security being the most common Istio use case) - each topic is likely a story on its own.

Ambient mode, when it arrives will also require its own set of documentation for the above topics (could either be combined into ambient vs sidecar sections for each doc) or separate sections entirely.

Note: The aim is here is not to duplicate upstream doc, but to provide high level use case guidance in a way that will make it easier for users to navigate the upstream docs.

This is not a 3.0 must have, but very much a nice to have at any time.