// NewImagePolicyWebhook a new imagePolicyWebhook from the provided config file.
// The config file is specified by --admission-controller-config-file and has the
// following format for a webhook:
//
// {
// "imagePolicy": {
// "kubeConfigFile": "path/to/kubeconfig/for/backend",
// "allowTTL": 30, # time in s to cache approval
// "denyTTL": 30, # time in s to cache denial
// "retryBackoff": 500, # time in ms to wait between retries
// "defaultAllow": true # determines behavior if the webhook backend fails
// }
// }
//
// The config file may be json or yaml.
//
// The kubeconfig property refers to another file in the kubeconfig format which
// specifies how to connect to the webhook backend.
//
// The kubeconfig'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-imagepolicy-service
// cluster:
// certificate-authority: /path/to/ca.pem # CA for verifying the remote service.
// server: https://images.example.com/policy # 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 NewImagePolicyWebhook(configFile io.Reader) (admission.Interface, error) {
// TODO: move this to a versioned configuration file format
var config AdmissionConfig
d := yaml.NewYAMLOrJSONDecoder(configFile, 4096)
err := d.Decode(&config)
if err != nil {
return nil, err
}
whConfig := config.ImagePolicyWebhook
if err := normalizeWebhookConfig(&whConfig); err != nil {
return nil, err
}
gw, err := webhook.NewGenericWebhook(whConfig.KubeConfigFile, groupVersions, whConfig.RetryBackoff)
if err != nil {
return nil, err
}
return &imagePolicyWebhook{
Handler: admission.NewHandler(admission.Create, admission.Update),
webhook: gw,
responseCache: cache.NewLRUExpireCache(1024),
allowTTL: whConfig.AllowTTL,
denyTTL: whConfig.DenyTTL,
defaultAllow: whConfig.DefaultAllow,
}, nil
}
// newWithBackoff allows tests to skip the sleep.
func newWithBackoff(subjectAccessReview authorizationclient.SubjectAccessReviewInterface, authorizedTTL, unauthorizedTTL, initialBackoff time.Duration) (*WebhookAuthorizer, error) {
return &WebhookAuthorizer{
subjectAccessReview: subjectAccessReview,
responseCache: cache.NewLRUExpireCache(1024),
authorizedTTL: authorizedTTL,
unauthorizedTTL: unauthorizedTTL,
initialBackoff: initialBackoff,
}, nil
}
// newWithBackoff allows tests to skip the sleep.
func newWithBackoff(tokenReview authenticationclient.TokenReviewInterface, ttl, initialBackoff time.Duration) (*WebhookTokenAuthenticator, error) {
return &WebhookTokenAuthenticator{tokenReview, cache.NewLRUExpireCache(1024), ttl, initialBackoff}, nil
}