[stable] multi-cluster support

[stevenctl]

beta issue: https://github.com/istio/enhancements/issues/13

This document covers the stability of multi-primary and primary-remote configurations.

This does not include:

• external control plane
• multi-network

Stable Feature Requirements

This page lists the requirements for promoting multicluster to stable. Please check off and document the steps as they are completed.

Requirements

Features/Fixes:

• [x] https://github.com/istio/istio/issues/32364
• [x] headless services (https://github.com/istio/istio/issues/27342, https://github.com/istio/istio/issues/29969)
• [x] https://github.com/istio/istio/issues/31787
• [x] https://github.com/istio/istio/issues/29335
• [x] https://github.com/istio/istio/issues/31464
• [x] https://github.com/istio/istio/issues/28906
• [x] https://github.com/istio/istio/issues/30625
• [x] https://github.com/istio/istio/issues/29900
• [x] https://github.com/istio/istio/issues/29482
• [x] https://github.com/istio/istio/issues/27420
  • [X] Re-enable tests (temporarily in a separate prow job(s) using test framework settting
  • [] A workaround for our test infra that avoids patching ISTIOD_CUSTOM_HOST (to closer match what we document for users).
  • https://github.com/istio/istio/issues/33619
  • [x] Document installation steps. (https://github.com/istio/istio.io/issues/9618)
• [ ] bug-report support https://github.com/istio/istio/issues/32321

Tests:

• [x] multicluster networking ingress coverage (https://github.com/istio/istio/issues/32282)
• [ ] ~Draining traffic to a cluster and removing it from a mesh~
• [ ] security test flakes (https://github.com/istio/istio/issues/32172)
• [ ] security test gaps (https://github.com/istio/istio/issues/32287)
• [ ] test failures: corsPolity breaks using VM + Multi-Cluster (https://github.com/istio/istio/issues/31532)
• [ ] gRPC in security tests (https://github.com/istio/istio/issues/32280)

• [ ] enhance mirroring test checks (https://github.com/istio/istio/issues/32284)

  Docs:

Each task here also includes providing an automated test for the document on istio.io.

• [ ] headless/statefulsets - https://github.com/istio/istio.io/issues/8832
• [ ] https://github.com/istio/istio.io/issues/8605
• [ ] https://github.com/istio/istio.io/issues/8603
• [ ] https://github.com/istio/istio.io/issues/8469
• [ ] https://github.com/istio/istio.io/issues/9559
• [x] https://github.com/istio/istio.io/issues/9558
• [ ] instructions for revisioned upgrade of east-west gateway (https://github.com/istio/istio/issues/30526)

Other:

• [ ] Revisit the supportability review for beta

Approvals:

• [ ] The appropriate work group(s) have reviewed and approved promotion of the feature.
• [ ] The supportability review panel has reviewed promotion of the feature.
• [ ] The TOC has reviewed and approved promotion of the feature as part of the road map for a release.

[hzxuzhonghu]

We also need cluster-aware load balancing when clusters are in different networks

[stevenctl]

Multi-network is a separate concern from multi-cluster

[brian-avery]

@stevenctl can you please create a PR for this following https://github.com/istio/enhancements/blob/master/FEATURES.md? Thanks

[stevenctl]

@brian-avery I started moving it over... but I'll do that as the last step. That format is pretty hard to use as a living checklist while the work is in progress.