Kubernetes 1.30：多 Webhook 和模块化授权变得更加容易

apiVersion: apiserver.config.k8s.io/v1beta1
kind: AuthorizationConfiguration
authorizers:
  - type: Webhook
    # Name used to describe the authorizer
    # This is explicitly used in monitoring machinery for metrics
    # Note:
    #   - Validation for this field is similar to how K8s labels are validated today.
    # Required, with no default
    name: webhook
    webhook:
      # The duration to cache 'authorized' responses from the webhook
      # authorizer.
      # Same as setting `--authorization-webhook-cache-authorized-ttl` flag
      # Default: 5m0s
      authorizedTTL: 30s
      # The duration to cache 'unauthorized' responses from the webhook
      # authorizer.
      # Same as setting `--authorization-webhook-cache-unauthorized-ttl` flag
      # Default: 30s
      unauthorizedTTL: 30s
      # Timeout for the webhook request
      # Maximum allowed is 30s.
      # Required, with no default.
      timeout: 3s
      # The API version of the authorization.k8s.io SubjectAccessReview to
      # send to and expect from the webhook.
      # Same as setting `--authorization-webhook-version` flag
      # Required, with no default
      # Valid values: v1beta1, v1
      subjectAccessReviewVersion: v1
      # MatchConditionSubjectAccessReviewVersion specifies the SubjectAccessReview
      # version the CEL expressions are evaluated against
      # Valid values: v1
      # Required, no default value
      matchConditionSubjectAccessReviewVersion: v1
      # Controls the authorization decision when a webhook request fails to
      # complete or returns a malformed response or errors evaluating
      # matchConditions.
      # Valid values:
      #   - NoOpinion: continue to subsequent authorizers to see if one of
      #     them allows the request
      #   - Deny: reject the request without consulting subsequent authorizers
      # Required, with no default.
      failurePolicy: Deny
      connectionInfo:
        # Controls how the webhook should communicate with the server.
        # Valid values:
        # - KubeConfigFile: use the file specified in kubeConfigFile to locate the
        #   server.
        # - InClusterConfig: use the in-cluster configuration to call the
        #   SubjectAccessReview API hosted by kube-apiserver. This mode is not
        #   allowed for kube-apiserver.
        type: KubeConfigFile
        # Path to KubeConfigFile for connection info
        # Required, if connectionInfo.Type is KubeConfigFile
        kubeConfigFile: /kube-system-authz-webhook.yaml
        # matchConditions is a list of conditions that must be met for a request to be sent to this
        # webhook. An empty list of matchConditions matches all requests.
        # There are a maximum of 64 match conditions allowed.
        #
        # The exact matching logic is (in order):
        #   1. If at least one matchCondition evaluates to FALSE, then the webhook is skipped.
        #   2. If ALL matchConditions evaluate to TRUE, then the webhook is called.
        #   3. If at least one matchCondition evaluates to an error (but none are FALSE):
        #      - If failurePolicy=Deny, then the webhook rejects the request
        #      - If failurePolicy=NoOpinion, then the error is ignored and the webhook is skipped
      matchConditions:
      # expression represents the expression which will be evaluated by CEL. Must evaluate to bool.
      # CEL expressions have access to the contents of the SubjectAccessReview in v1 version.
      # If version specified by subjectAccessReviewVersion in the request variable is v1beta1,
      # the contents would be converted to the v1 version before evaluating the CEL expression.
      #
      # Documentation on CEL: https://kubernetes.ac.cn/docs/reference/using-api/cel/
      #
      # only send resource requests to the webhook
      - expression: has(request.resourceAttributes)
      # only intercept requests to kube-system
      - expression: request.resourceAttributes.namespace == 'kube-system'
      # don't intercept requests from kube-system service accounts
      - expression: "!('system:serviceaccounts:kube-system' in request.groups)"
  - type: Node
    name: node
  - type: RBAC
    name: rbac
  - type: Webhook
    name: in-cluster-authorizer
    webhook:
      authorizedTTL: 5m
      unauthorizedTTL: 30s
      timeout: 3s
      subjectAccessReviewVersion: v1
      failurePolicy: NoOpinion
      connectionInfo:
        type: InClusterConfig

apiVersion: apiserver.config.k8s.io/v1beta1
kind: AuthorizationConfiguration
authorizers:
  - type: Webhook
    name: system-crd-protector
    webhook:
      unauthorizedTTL: 30s
      timeout: 3s
      subjectAccessReviewVersion: v1
      matchConditionSubjectAccessReviewVersion: v1
      failurePolicy: Deny
      connectionInfo:
        type: KubeConfigFile
        kubeConfigFile: /files/kube-system-authz-webhook.yaml
      matchConditions:
      # only send resource requests to the webhook
      - expression: has(request.resourceAttributes)
      # only intercept requests for CRDs
      - expression: request.resourceAttributes.resource.resource = "customresourcedefinitions"
      - expression: request.resourceAttributes.resource.group = ""
      # only intercept update, patch, delete, or deletecollection requests
      - expression: request.resourceAttributes.verb in ['update', 'patch', 'delete','deletecollection']
  - type: Node
  - type: RBAC

apiVersion: apiserver.config.k8s.io/v1beta1
kind: AuthorizationConfiguration
authorizers:
  - type: Webhook
    name: system-crd-protector
    webhook:
      unauthorizedTTL: 30s
      timeout: 3s
      subjectAccessReviewVersion: v1
      matchConditionSubjectAccessReviewVersion: v1
      failurePolicy: Deny
      connectionInfo:
        type: KubeConfigFile
        kubeConfigFile: /files/kube-system-authz-webhook.yaml
      matchConditions:
      # only send resource requests to the webhook
      - expression: has(request.resourceAttributes)
      # only intercept requests for CRDs
      - expression: request.resourceAttributes.resource.resource = "customresourcedefinitions"
      - expression: request.resourceAttributes.resource.group = ""
      # only intercept update, patch, delete, or deletecollection requests
      - expression: request.resourceAttributes.verb in ['update', 'patch', 'delete','deletecollection']
  - type: Node
  - type: RBAC
  - name: opa
    type: Webhook
    webhook:
      unauthorizedTTL: 30s
      timeout: 3s
      subjectAccessReviewVersion: v1
      matchConditionSubjectAccessReviewVersion: v1
      failurePolicy: Deny
      connectionInfo:
        type: KubeConfigFile
        kubeConfigFile: /files/opa-default-authz-webhook.yaml
      matchConditions:
      # only send resource requests to the webhook
      - expression: has(request.resourceAttributes)
      # only intercept requests to default namespace
      - expression: request.resourceAttributes.namespace == 'default'
      # don't intercept requests from default service accounts
      - expression: "!('system:serviceaccounts:default' in request.groups)"

kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
featureGates:
  StructuredAuthorizationConfiguration: true  # enabled by default in v1.30
kubeadmConfigPatches:
  - |
    kind: ClusterConfiguration
    metadata:
      name: config
    apiServer:
      extraArgs:
        authorization-config: "/files/authorization_config.yaml"
      extraVolumes:
      - name: files
        hostPath: "/files"
        mountPath: "/files"
        readOnly: true    
nodes:
- role: control-plane
  extraMounts:
  - hostPath: files
    containerPath: /files