Fix validation of CIDR fields

[danwinship]

re kubernetes/kubernetes#134224; isCIDR() allows both "mask-like" CIDRs ("192.168.0.0/24") and "address-like" CIDRs ("192.168.0.5/24"). We only want the former.

(If isCIDR() gets changed, then the extra clause here will just be a no-op, but we'll have better backward-compatibility this way.)

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[danwinship]

uh...

The CustomResourceDefinition "adminnetworkpolicies.policy.networking.k8s.io" is invalid: spec.validation.openAPIV3Schema.properties[spec].properties[egress].items.properties[to].items.properties[networks].items.x-kubernetes-validations[0].rule: Forbidden: estimated rule cost exceeds budget by factor of 1.475000x (try simplifying the rule, or adding maxItems, maxProperties, and maxLength where arrays, maps, and strings are declared)

[danwinship]

@tssurya @npinaeva any ideas about how to deal with that CEL cost error? ^^^

[Copilot]

Pull Request Overview

This PR enhances CIDR validation in Kubernetes Custom Resource Definitions to ensure only "mask-like" CIDRs (e.g., "192.168.0.0/24") are accepted, rejecting "address-like" CIDRs (e.g., "192.168.0.5/24").

• Updated validation rules from isCIDR(self) to isCIDR(self) && cidr(self) == cidr(self).masked()
• Applied changes consistently across both standard and experimental CRD files
• Modified Go type definitions to reflect the stricter validation requirements

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
config/crd/standard/policy.networking.k8s.io_clusternetworkpolicies.yaml	Updated CIDR validation rule to enforce mask-like format
config/crd/standard/policy.networking.k8s.io_baselineadminnetworkpolicies.yaml	Updated CIDR validation rule to enforce mask-like format
config/crd/standard/policy.networking.k8s.io_adminnetworkpolicies.yaml	Updated CIDR validation rule to enforce mask-like format
config/crd/experimental/policy.networking.k8s.io_clusternetworkpolicies.yaml	Updated CIDR validation rule to enforce mask-like format
config/crd/experimental/policy.networking.k8s.io_baselineadminnetworkpolicies.yaml	Updated CIDR validation rule to enforce mask-like format
config/crd/experimental/policy.networking.k8s.io_adminnetworkpolicies.yaml	Updated CIDR validation rule to enforce mask-like format
apis/v1alpha2/clusternetworkpolicy_types.go	Updated CIDR type validation annotation to enforce mask-like format
apis/v1alpha1/shared_types.go	Updated CIDR type validation annotation to enforce mask-like format

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[tssurya]

@tssurya @npinaeva any ideas about how to deal with that CEL cost error? ^^^

this suggests something is unbounded OR if everything is bounded then yea I remember hitting this error before and I had to play around with the maximum numbers to make it reasonable.
IIRC the problem is that we can have 100 egress rules and each rule can have 100 peers and then each peer could be 25 network cidrs.. that's too much? 100x100x25?
the only way to fix this is to reduce this number somewhere..

so see if 20 cidr's or 15 fixes this?

I remember I chose 25 cidrs cause back then as well cost exceeded for higher numbers.. :)

[aojea]

uh...

The CustomResourceDefinition "adminnetworkpolicies.policy.networking.k8s.io" is invalid: spec.validation.openAPIV3Schema.properties[spec].properties[egress].items.properties[to].items.properties[networks].items.x-kubernetes-validations[0].rule: Forbidden: estimated rule cost exceeds budget by factor of 1.475000x (try simplifying the rule, or adding maxItems, maxProperties, and maxLength where arrays, maps, and strings are declared)

@tssurya @npinaeva any ideas about how to deal with that CEL cost error? ^^^

this suggests something is unbounded OR if everything is bounded then yea I remember hitting this error before and I had to play around with the maximum numbers to make it reasonable. IIRC the problem is that we can have 100 egress rules and each rule can have 100 peers and then each peer could be 25 network cidrs.. that's too much? 100x100x25? the only way to fix this is to reduce this number somewhere..

so see if 20 cidr's or 15 fixes this?

I remember I chose 25 cidrs cause back then as well cost exceeded for higher numbers.. :)

@jpbetz @cici37 any best practices or guidelines we can follow here?

[bowei]

/lgtm

[danwinship]

kubernetes/kubernetes#120973 (comment)

[k8s-ci-robot]

New changes are detected. LGTM label has been removed.

[npinaeva]

will rebasing help since #329 merged?

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[danwinship]

/retest

[danwinship]

will rebasing help since #329 merged?

not sure if that helped at all or not, but it seems that something about CEL cost computation changed in the last few releases, and updating the e2e test to test against a newer apiserver fixes things. (Just #329 without the new apiserver does not fix it.)

Oh, although that doesn't actually help, because that would mean the new CRDs won't work with older k8s releases.

[danwinship]

/hold

removing this from the v1alpha2 milestone. we'll have to figure this out later.

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PR needs rebase.

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