CEL-based admission webhook match conditions

[tallclair]

Enhancement Description

• One-line enhancement description (can be used as a release note): Introduce CEL expression filters to webhooks, to allow webhooks to be scoped more narrowly.
• Kubernetes Enhancement Proposal: https://github.com/kubernetes/enhancements/tree/master/keps/sig-api-machinery/3716-admission-webhook-match-conditions
• Discussion Link: https://docs.google.com/document/d/1x9RNaaysyO0gXHIr1y50QFbiL1x8OWnk2v3XnrdkT5Y/edit#bookmark=id.55kd8uoz25p5
• Primary contact (assignee): @tallclair
• Responsible SIGs: api-machinery
• Enhancement target (which target equals to which milestone):
  • Alpha release target (x.y): 1.27
  • Beta release target (x.y):
  • Stable release target (x.y):
• Alpha
  • KEP (k/enhancements) update PR(s):
    • KEP-3716: Admission Webhook Match Conditions #3717
  • Code (k/k) update PR(s):
    • Matchconditions admission webhooks alpha implementation for kep-3716 kubernetes#116261
    • Graduate AdmissionWebhookMatchCondition to beta kubernetes#119380
  • Docs (k/website) update PR(s):
    • AdmissionWebhookMatchConditions feature documentation website#40058
• Beta
  • KEP (k/enhancements) update PR(s):
  • Code (k/k) update PR(s):
  • Docs (k/website) update(s):
• Stable
  • KEP (k/enhancements) update PR(s): KEP-3716: graduate to stable for 1.30 #4435
  • Code (k/k) update PR(s):
    • kep-3716 GA, remove feature gate kubernetes#123560
    • promote match conditions e2e tests to conformance kubernetes#123564
  • Docs (k/website) update(s): [docs placeholder] Matchconditions 1.30 website#45279

Please keep this description up to date. This will help the Enhancement Team to track the evolution of the enhancement efficiently.

[sftim]

Is this for admission webhooks only, or for all HTTP callouts (eg https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#imagepolicywebhook and https://kubernetes.io/docs/reference/access-authn-authz/webhook/)?

[tallclair]

@sftim this is only for admission webhooks (updated the title). We've also had conversations about doing something similar for authorization webhooks, but that will probably be folded in with #3221

[logicalhan]

Is there a KEP for this I can review for PRR?

[fsmunoz]

Hello @tallclair 👋, v1.27 Enhancements team here.

Just checking in as we approach enhancements freeze on 18:00 PDT Thursday 9th February 2023.

This enhancement is targeting for stage alpha for 1.27 (please correct me, if otherwise)

Here's where this enhancement currently stands:

• KEP readme using the latest template has been merged into the k/enhancements repo.
• KEP status is marked as implementable for latest-milestone: 1.27
• KEP readme has a updated detailed test plan section filled out
• KEP readme has up to date graduation criteria
• KEP has a production readiness review that has been completed and merged into k/enhancements.

For this enhancement, the first thing we need is access to the KEP so we can then confirm the rest.

The status of this enhancement is marked as at risk. Please keep the issue description up-to-date with appropriate stages as well. Thank you!

[logicalhan]

@sftim this is only for admission webhooks (updated the title). We've also had conversations about doing something similar for authorization webhooks, but that will probably be folded in with #3221

If so, should this be tracked separately? I've confused about what I'm supposed to review for PRR here.

[sftim]

The problem was the original title - the rename fully addressed my concern.

[sftim]

If we want CEL conditions for admission authz webhooks, that change won't be part of this KEP.

[fsmunoz]

Hi @logicalhan , an update based on the linked KEP PR.

This enhancement is targeting for stage alpha for 1.27 (please correct me, if otherwise)

Here's where this enhancement currently stands, assuming #3717 in it's current state:

• KEP readme using the latest template has been merged into the k/enhancements repo.
• KEP status is marked as implementable for latest-milestone: 1.27
• KEP readme has a updated detailed test plan section filled out
• KEP readme has up to date graduation criteria
• KEP has a production readiness review that has been completed and merged into k/enhancements.

For this enhancement, the following would need to be updated, assuming #3717 in it's current state:

• Use the latest version of the template. There is an additional question on the Scalability section of the PRR, although in one that isn't mandatory for alpha, it would be a good time to add it and sync with the latest template structure.
• An updated Test Plan, with the sections filled.
• Up-to-date graduation criteria filled.

The status of this enhancement is marked as at risk. Please keep the issue description up-to-date with appropriate stages as well. Thank you!

[tallclair]

@fsmunoz Thanks for the list. The remaining items are addressed in #3861

@logicalhan sorry for missing your earlier questions! It looks like you figured it out, but please ping me on chat/slack if you have any outstanding questions.

[fsmunoz]

Hello @tallclair , thank you.

I'm marking this as tracked with two comments:

• The Test Plan has TBD information that should be analysed and reviewed.
• The Graduation Criteria would benefit from including other stages, but it does contain the alpha one.

This enhancement is ready to be traced for graduation to alpha in v1.27

/stage alpha
/label tracked/yes

[k8s-ci-robot]

@fsmunoz: The label(s) /label stage/alpha cannot be applied. These labels are supported: api-review, tide/merge-method-merge, tide/merge-method-rebase, tide/merge-method-squash, team/katacoda, refactor, lead-opted-in, tracked/no, tracked/out-of-tree, tracked/yes. Is this label configured under labels -> additional_labels or labels -> restricted_labels in plugin.yaml?

In response to this:

Hello @tallclair , thank you.

I'm marking this as tracked with two comments:

• The Test Plan has TBD information that should be analysed and reviewed.
• The Graduation Criteria would benefit from including other stages, but it does contain the alpha one.

This enhancement is ready to be traced for graduation to alpha in v1.27

/label stage/alpha
/label tracked/yes

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[fsmunoz]

/stage alpha

[ivelichkovich]

Just raised a PR: #4513

[celestehorgan]

Hello @tallclair 👋, 1.30 Docs Shadow here.
Does this enhancement work planned for 1.30 require any new docs or modification to existing docs?
If so, please follows the steps here to open a PR against dev-1.30 branch in the k/website repo. This PR can be just a placeholder at this time and must be created before Thursday February 22nd 2024 18:00 PDT.
Also, take a look at Documenting for a release to get yourself familiarize with the docs requirement for the release.
Thank you!

---

(At a minimum, please remember to update the feature flags to stable for this release ✨)

[a-mccarthy]

Hi @tallclair,

👋 from the v1.30 Communications Team! We'd love for you to opt in to write a feature blog about your enhancement!

We encourage blogs for features including, but not limited to: breaking changes, features and changes important to our users, and features that have been in progress for a long time and are graduating.

To opt in, you need to open a Feature Blog placeholder PR against the website repository.
The placeholder PR deadline is 27th February, 2024.
Here's the 1.30 Release Calendar

[tallclair]

/assign @ivelichkovich

Igor, can you take a look at the docs & comms requests above?

[sreeram-venkitesh]

Hey again @tallclair, @jpbetz 👋 v1.30 Enhancements team here,

Just checking in as we approach code freeze at 02:00 UTC Wednesday 6th March 2024.

Here's where this enhancement currently stands:

• All PRs to the Kubernetes repo that are related to your enhancement are linked in the above issue description (for tracking purposes).
• All PR/s are ready to be merged (they have approved and lgtm labels applied) by the code freeze deadline. This includes tests.

For this enhancement, it looks like the following PRs are open and need to be merged before code freeze (and we need to update the issue description to include all the related PRs of this KEP):

• kep-3716 GA, remove feature gate kubernetes#123560

Currently, I'm marking this KEP as At Risk for Code Freeze. Also, please let me know if there are other PRs in k/k we should be tracking for this KEP. As always, we are here to help if any questions come up. Thanks!

[sreeram-venkitesh]

@tallclair, @jpbetz: Are all the code PRs for this KEP merged? Are there any other PRs we should track other than kubernetes/kubernetes#123560?

[jpbetz]

Are all the code PRs for this KEP merged? Are there any other PRs we should track other than kubernetes/kubernetes#123560?

Yes. These two PRs were merged to complete the GA promotion:

• kep-3716 GA, remove feature gate kubernetes#123560
• promote match conditions e2e tests to conformance kubernetes#123564

I've added them to the issue description as well (I also added the doc placeholder PR).

Let us know if you see anything missing, our understanding is that this enhancement is fully graduated and should be tracked as such at part of 1.30. Thanks!

[sreeram-venkitesh]

Thank you @jpbetz!

With all the implementation (code related) PRs merged as per the issue description:

• kep-3716 GA, remove feature gate kubernetes#123560
• promote match conditions e2e tests to conformance kubernetes#123564

This enhancement is now marked as tracked for code freeze for the 1.30 Code Freeze!

[ivelichkovich]

Raised a docs PR ready to review for this: kubernetes/website#45525

[sreeram-venkitesh]

Hi @tallclair @jpbetz 👋, 1.31 Enhancements Lead here.

Since this KEP graduated to GA in v1.30, please make sure to update the status field from implementable to implemented in the kep.yaml file here, after which we can close the issue. Please let me know if this sounds good.

/remove-label lead-opted-in

[ivelichkovich]

Hi @tallclair @jpbetz 👋, 1.31 Enhancements Lead here.

Since this KEP graduated to GA in v1.30, please make sure to update the status field from implementable to implemented in the kep.yaml file here, after which we can close the issue. Please let me know if this sounds good.

/remove-label lead-opted-in

Yes I can update this

[ivelichkovich]

PR here: #4637