Stop releasing istio.yaml

[mattmoor]

In what area(s)?

/area networking
/area test-and-release

What version of Knative?

HEAD

Expected Behavior

We should not release istio*.yaml. These are curated for the purposes of our own testing, and not something we can/should support. Instructions for standing up Istio in docs should be folded into the instructions for setting up a Kubernetes cluster (this would also enable vendors to direct folks to Istio products).

Actual Behavior

We do.

cc @tcnghia @adrcunha @samodell @RichieEscarez

[bbrowning]

Just voicing my support here - we spend a non-trivial amount of energy documenting and fixing bugs with Istio installations. And I've had feedback that users are confused how to use Knative with existing Istio installations, which would be alleviated if we only assumed existing Istio installations if you want Istio.

This ties in nicely work our other work to remove the hard dependencies on Istio and make it an optional piece users can choose to bring if they want or not.

[jchesterpivotal]

I'm also supportive, though perhaps for a different reason. If bundling Istio interferes with the immutability of Knative's releases (as it did recently because of upstream CVEs), then it should be unbundled. Based on other experiences I've had, this is a bit like switching from static linking to dynamic linking and the relative joys and sorrows thereof.

We'll need to consider our test matrix and how much of that matrix will belong to the project and how much would be allowed to flow down to release engineering efforts by vendors, or upstream to Istio itself.

[duglin]

Will we still ship the smaller yaml of knative specific istio stuff we install? See: #3640

[tcnghia]

@duglin we will need to add instruction how to install it from Istio and also how to setup Knative to refer to those Istio customization.

[mattmoor]

The change to generate-yamls.sh is already done. We need docs changes now.

[mattmoor]

@duglin We can still reference these files in-tree since they aren't "built". However, I think the best place for this kind of thing is going to be: knative/docs#1244

Sounds like we need a docs update to even cover installing these extras?