webhook

Documentation

Overview

Package webhook implements the authorizer.Authorizer interface using HTTP webhooks.

Index

• type WebhookAuthorizer
  • func New(kubeConfigFile string, authorizedTTL, unauthorizedTTL time.Duration) (*WebhookAuthorizer, error)
  • func (w *WebhookAuthorizer) Authorize(attr authorizer.Attributes) (authorized bool, reason string, err error)

Types

type WebhookAuthorizer

type WebhookAuthorizer struct {
	*webhook.GenericWebhook
	// contains filtered or unexported fields
}

func New

func New(kubeConfigFile string, authorizedTTL, unauthorizedTTL time.Duration) (*WebhookAuthorizer, error)

New creates a new WebhookAuthorizer from the provided kubeconfig file.

The config's cluster field is used to refer to the remote service, user refers to the returned authorizer.

# clusters refers to the remote service.
clusters:
- name: name-of-remote-authz-service
  cluster:
    certificate-authority: /path/to/ca.pem      # CA for verifying the remote service.
    server: https://authz.example.com/authorize # URL of remote service to query. Must use 'https'.

# users refers to the API server's webhook configuration.
users:
- name: name-of-api-server
  user:
    client-certificate: /path/to/cert.pem # cert for the webhook plugin to use
    client-key: /path/to/key.pem          # key matching the cert

For additional HTTP configuration, refer to the kubeconfig documentation http://kubernetes.io/v1.1/docs/user-guide/kubeconfig-file.html.

func (*WebhookAuthorizer) Authorize

func (w *WebhookAuthorizer) Authorize(attr authorizer.Attributes) (authorized bool, reason string, err error)

Authorize makes a REST request to the remote service describing the attempted action as a JSON serialized api.authorization.v1beta1.SubjectAccessReview object. An example request body is provided bellow.

{
  "apiVersion": "authorization.k8s.io/v1beta1",
  "kind": "SubjectAccessReview",
  "spec": {
    "resourceAttributes": {
      "namespace": "kittensandponies",
      "verb": "GET",
      "group": "group3",
      "resource": "pods"
    },
    "user": "jane",
    "group": [
      "group1",
      "group2"
    ]
  }
}

The remote service is expected to fill the SubjectAccessReviewStatus field to either allow or disallow access. A permissive response would return:

{
  "apiVersion": "authorization.k8s.io/v1beta1",
  "kind": "SubjectAccessReview",
  "status": {
    "allowed": true
  }
}

To disallow access, the remote service would return:

{
  "apiVersion": "authorization.k8s.io/v1beta1",
  "kind": "SubjectAccessReview",
  "status": {
    "allowed": false,
    "reason": "user does not have read access to the namespace"
  }
}