Files
spinifex/cmd/eks-token-webhook/tokenreview.go
T
Josh Siviour 5aaf8c23d2 fix(eks): make aws eks get-token → kubectl auth work end-to-end (Sprint 6f) (#303)
* feat(eks): webhook observability — console log sink + per-request TokenReview decision

* fix(eks): wire token-webhook authenticator into generated k3s apiserver config

The generated /etc/rancher/k3s/config.yaml overrides the AMI-baked
config.yaml.skel, but its kube-apiserver-arg list omitted the
authentication-token-webhook-config-file arg. The running apiserver
therefore never loaded the token webhook, so bearer tokens minted by
'aws eks get-token' 401'd without the webhook ever being invoked.

* fix(eks): echo TokenReview audiences so api-audiences apiserver accepts the principal

With --api-audiences set, kube-apiserver sends spec.audiences in the
TokenReview and discards an authenticated=true response that does not
confirm a matching audience. The webhook returned an empty
status.audiences, so a valid IAM principal surfaced as a 401. Echo the
request's audiences on success.

* fix(eks): pin token-webhook version v1 so apiserver accepts the response

kube-apiserver --authentication-token-webhook-version defaults to
v1beta1, but the eks-token-webhook responds with an
authentication.k8s.io/v1 TokenReview. The apiserver decodes the response
against the expected GVK and rejects the mismatch, surfacing a valid
principal as a 401. Pin v1 to match the webhook.
2026-06-06 22:11:50 +10:00

35 lines
1.2 KiB
Go

package main
// Minimal authentication.k8s.io/v1 TokenReview wire types. Hand-rolled to avoid
// pulling k8s.io/api into the spinifex module for these few fields; the shapes
// match what kube-apiserver sends and expects on the webhook contract.
type tokenReview struct {
APIVersion string `json:"apiVersion"`
Kind string `json:"kind"`
Spec tokenReviewSpec `json:"spec,omitzero"`
Status tokenReviewStatus `json:"status"`
}
type tokenReviewSpec struct {
Token string `json:"token"`
Audiences []string `json:"audiences,omitempty"`
}
type tokenReviewStatus struct {
Authenticated bool `json:"authenticated"`
User userInfo `json:"user,omitzero"`
// Audiences echoes the request's spec.audiences on success. When the
// apiserver runs with --api-audiences, it sends spec.audiences and discards
// an authenticated=true response that does not confirm a matching audience —
// so an empty Audiences here surfaces as a 401 despite a valid principal.
Audiences []string `json:"audiences,omitempty"`
Error string `json:"error,omitempty"`
}
type userInfo struct {
Username string `json:"username,omitempty"`
UID string `json:"uid,omitempty"`
Groups []string `json:"groups,omitempty"`
}