NK-47: Added missed files

webhooks/mutation.go

@@ -4,29 +4,49 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"os"
 
 	controller "github.com/nirmata/kube-policy/controller"
 	kubeclient "github.com/nirmata/kube-policy/kubeclient"
 	types "github.com/nirmata/kube-policy/pkg/apis/policy/v1alpha1"
 	v1beta1 "k8s.io/api/admission/v1beta1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	rest "k8s.io/client-go/rest"
 )
 
 // MutationWebhook is a data type that represents
-// buisness logic for resource mutation
+// business logic for resource mutation
 type MutationWebhook struct {
-	kubeclient *kubeclient.KubeClient
-	controller *controller.PolicyController
-	logger     *log.Logger
+	kubeclient   *kubeclient.KubeClient
+	controller   *controller.PolicyController
+	registration *MutationWebhookRegistration
+	logger       *log.Logger
 }
 
-// NewMutationWebhook is a method that returns new instance
-// of MutationWebhook struct
-func NewMutationWebhook(kubeclient *kubeclient.KubeClient, controller *controller.PolicyController, logger *log.Logger) (*MutationWebhook, error) {
-	if kubeclient == nil || controller == nil || logger == nil {
+// Registers mutation webhook in cluster and creates object for this webhook
+func CreateMutationWebhook(clientConfig *rest.Config, kubeclient *kubeclient.KubeClient, controller *controller.PolicyController, logger *log.Logger) (*MutationWebhook, error) {
+	if clientConfig == nil || kubeclient == nil || controller == nil {
 		return nil, errors.New("Some parameters are not set")
 	}
-	return &MutationWebhook{kubeclient: kubeclient, controller: controller, logger: logger}, nil
+
+	registration, err := NewMutationWebhookRegistration(clientConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	if logger == nil {
+		logger = log.New(os.Stdout, "Mutation WebHook: ", log.LstdFlags|log.Lshortfile)
+	}
+	return &MutationWebhook{
+		kubeclient:   kubeclient,
+		controller:   controller,
+		registration: registration,
+		logger:       logger,
+	}, nil
+}
+
+func (mw *MutationWebhook) Deregister() error {
+	return mw.registration.Deregister()
 }
 
 // Mutate applies admission to request

webhooks/registration.go

@@ -1,53 +1,85 @@
 package webhooks
 
 import (
+	"errors"
+	"fmt"
 	"io/ioutil"
 
 	"github.com/nirmata/kube-policy/config"
 
-	adm "k8s.io/api/admissionregistration/v1beta1"
+	admregapi "k8s.io/api/admissionregistration/v1beta1"
 	meta "k8s.io/apimachinery/pkg/apis/meta/v1"
-	admreg "k8s.io/client-go/kubernetes/typed/admissionregistration/v1beta1"
+	admregclient "k8s.io/client-go/kubernetes/typed/admissionregistration/v1beta1"
 	rest "k8s.io/client-go/rest"
 )
 
-func RegisterMutationWebhook(config *rest.Config) error {
-	registrationClient, err := admreg.NewForConfig(config)
-	if err != nil {
-		return err
-	}
-
-	_, err = registrationClient.MutatingWebhookConfigurations().Create(constructWebhookConfig(config))
-	if err != nil {
-		return err
-	}
-
-	return nil
+type MutationWebhookRegistration struct {
+	registrationClient *admregclient.AdmissionregistrationV1beta1Client
 }
 
-func constructWebhookConfig(configuration *rest.Config) *adm.MutatingWebhookConfiguration {
-	return &adm.MutatingWebhookConfiguration{
+func NewMutationWebhookRegistration(clientConfig *rest.Config) (*MutationWebhookRegistration, error) {
+	registrationClient, err := admregclient.NewForConfig(clientConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	webhookConfig, err := constructWebhookConfig(clientConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	oldConfig, err := registrationClient.MutatingWebhookConfigurations().Get(config.WebhookConfigName, meta.GetOptions{})
+	if oldConfig != nil && oldConfig.ObjectMeta.UID != "" {
+		// Normally webhook configuration should be deleted from cluster when controller end his work.
+		// But if old configuration is detected in cluster, it should be replaced by new one.
+		err = registrationClient.MutatingWebhookConfigurations().Delete(config.WebhookConfigName, &meta.DeleteOptions{})
+		if err != nil {
+			return nil, errors.New(fmt.Sprintf("Failed to delete old webhook configuration: %v", err))
+		}
+	}
+
+	_, err = registrationClient.MutatingWebhookConfigurations().Create(webhookConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	return &MutationWebhookRegistration{
+		registrationClient: registrationClient,
+	}, nil
+}
+
+func (mwr *MutationWebhookRegistration) Deregister() error {
+	return mwr.registrationClient.MutatingWebhookConfigurations().Delete(config.MutationWebhookName, &meta.DeleteOptions{})
+}
+
+func constructWebhookConfig(configuration *rest.Config) (*admregapi.MutatingWebhookConfiguration, error) {
+	caData := ExtractCA(configuration)
+	if len(caData) == 0 {
+		return nil, errors.New("Unable to extract CA data from configuration")
+	}
+
+	return &admregapi.MutatingWebhookConfiguration{
 		ObjectMeta: meta.ObjectMeta{
 			Name:   config.WebhookConfigName,
 			Labels: config.WebhookConfigLabels,
 		},
-		Webhooks: []adm.Webhook{
-			adm.Webhook{
+		Webhooks: []admregapi.Webhook{
+			admregapi.Webhook{
 				Name: config.MutationWebhookName,
-				ClientConfig: adm.WebhookClientConfig{
-					Service: &adm.ServiceReference{
+				ClientConfig: admregapi.WebhookClientConfig{
+					Service: &admregapi.ServiceReference{
 						Namespace: config.WebhookServiceNamespace,
 						Name:      config.WebhookServiceName,
 						Path:      &config.WebhookServicePath,
 					},
-					CABundle: ExtractCA(configuration),
+					CABundle: caData,
 				},
-				Rules: []adm.RuleWithOperations{
-					adm.RuleWithOperations{
-						Operations: []adm.OperationType{
-							adm.Create,
+				Rules: []admregapi.RuleWithOperations{
+					admregapi.RuleWithOperations{
+						Operations: []admregapi.OperationType{
+							admregapi.Create,
 						},
-						Rule: adm.Rule{
+						Rule: admregapi.Rule{
 							APIGroups: []string{
 								"*",
 							},
@@ -62,7 +94,7 @@ func constructWebhookConfig(configuration *rest.Config) *adm.MutatingWebhookConf
 				},
 			},
 		},
-	}
+	}, nil
 }
 
 func ExtractCA(config *rest.Config) (result []byte) {