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kyverno/pkg/webhookconfig/registration.go
2019-11-18 11:48:36 -08:00

283 lines
9.6 KiB
Go

package webhookconfig
import (
"errors"
"sync"
"time"
"github.com/golang/glog"
client "github.com/nirmata/kyverno/pkg/dclient"
admregapi "k8s.io/api/admissionregistration/v1beta1"
errorsapi "k8s.io/apimachinery/pkg/api/errors"
rest "k8s.io/client-go/rest"
)
const (
MutatingWebhookConfigurationKind string = "MutatingWebhookConfiguration"
ValidatingWebhookConfigurationKind string = "ValidatingWebhookConfiguration"
)
// WebhookRegistrationClient is client for registration webhooks on cluster
type WebhookRegistrationClient struct {
client *client.Client
clientConfig *rest.Config
// serverIP should be used if running Kyverno out of clutser
serverIP string
timeoutSeconds int32
}
// NewWebhookRegistrationClient creates new WebhookRegistrationClient instance
func NewWebhookRegistrationClient(
clientConfig *rest.Config,
client *client.Client,
serverIP string,
webhookTimeout int32) *WebhookRegistrationClient {
return &WebhookRegistrationClient{
clientConfig: clientConfig,
client: client,
serverIP: serverIP,
timeoutSeconds: webhookTimeout,
}
}
// Register creates admission webhooks configs on cluster
func (wrc *WebhookRegistrationClient) Register() error {
if wrc.serverIP != "" {
glog.Infof("Registering webhook with url https://%s\n", wrc.serverIP)
}
// For the case if cluster already has this configs
// remove previously create webhookconfigurations if any
// webhook configurations are created dynamically based on the policy resources
wrc.removeWebhookConfigurations()
// Static Webhook configuration on Policy CRD
// create Policy CRD validating webhook configuration resource
// used for validating Policy CR
if err := wrc.createPolicyValidatingWebhookConfiguration(); err != nil {
return err
}
// create Policy CRD validating webhook configuration resource
// used for defauling values in Policy CR
if err := wrc.createPolicyMutatingWebhookConfiguration(); err != nil {
return err
}
// create Verify mutating webhook configuration resource
// that is used to check if admission control is enabled or not
if err := wrc.createVerifyMutatingWebhookConfiguration(); err != nil {
return err
}
return nil
}
// RemoveWebhookConfigurations removes webhook configurations for reosurces and policy
// called during webhook server shutdown
func (wrc *WebhookRegistrationClient) RemoveWebhookConfigurations(cleanUp chan<- struct{}) {
//TODO: dupliate, but a placeholder to perform more error handlind during cleanup
wrc.removeWebhookConfigurations()
// close channel to notify cleanup is complete
close(cleanUp)
}
//CreateResourceMutatingWebhookConfiguration create a Mutatingwebhookconfiguration resource for all resource type
// used to forward request to kyverno webhooks to apply policeis
// Mutationg webhook is be used for Mutating & Validating purpose
func (wrc *WebhookRegistrationClient) CreateResourceMutatingWebhookConfiguration() error {
var caData []byte
var config *admregapi.MutatingWebhookConfiguration
// read CA data from
// 1) secret(config)
// 2) kubeconfig
if caData = wrc.readCaData(); caData == nil {
return errors.New("Unable to extract CA data from configuration")
}
// if serverIP is specified we assume its debug mode
if wrc.serverIP != "" {
// debug mode
// clientConfig - URL
config = wrc.contructDebugMutatingWebhookConfig(caData)
} else {
// clientConfig - service
config = wrc.constructMutatingWebhookConfig(caData)
}
_, err := wrc.client.CreateResource(MutatingWebhookConfigurationKind, "", *config, false)
if errorsapi.IsAlreadyExists(err) {
glog.V(4).Infof("resource mutating webhook configuration %s, already exists. not creating one", config.Name)
return nil
}
if err != nil {
glog.V(4).Infof("failed to create resource mutating webhook configuration %s: %v", config.Name, err)
return err
}
return nil
}
//registerPolicyValidatingWebhookConfiguration create a Validating webhook configuration for Policy CRD
func (wrc *WebhookRegistrationClient) createPolicyValidatingWebhookConfiguration() error {
var caData []byte
var config *admregapi.ValidatingWebhookConfiguration
// read CA data from
// 1) secret(config)
// 2) kubeconfig
if caData = wrc.readCaData(); caData == nil {
return errors.New("Unable to extract CA data from configuration")
}
// if serverIP is specified we assume its debug mode
if wrc.serverIP != "" {
// debug mode
// clientConfig - URL
config = wrc.contructDebugPolicyValidatingWebhookConfig(caData)
} else {
// clientConfig - service
config = wrc.contructPolicyValidatingWebhookConfig(caData)
}
// create validating webhook configuration resource
if _, err := wrc.client.CreateResource(ValidatingWebhookConfigurationKind, "", *config, false); err != nil {
return err
}
glog.V(4).Infof("created Validating Webhook Configuration %s ", config.Name)
return nil
}
func (wrc *WebhookRegistrationClient) createPolicyMutatingWebhookConfiguration() error {
var caData []byte
var config *admregapi.MutatingWebhookConfiguration
// read CA data from
// 1) secret(config)
// 2) kubeconfig
if caData = wrc.readCaData(); caData == nil {
return errors.New("Unable to extract CA data from configuration")
}
// if serverIP is specified we assume its debug mode
if wrc.serverIP != "" {
// debug mode
// clientConfig - URL
config = wrc.contructDebugPolicyMutatingWebhookConfig(caData)
} else {
// clientConfig - service
config = wrc.contructPolicyMutatingWebhookConfig(caData)
}
// create mutating webhook configuration resource
if _, err := wrc.client.CreateResource(MutatingWebhookConfigurationKind, "", *config, false); err != nil {
return err
}
glog.V(4).Infof("created Mutating Webhook Configuration %s ", config.Name)
return nil
}
func (wrc *WebhookRegistrationClient) createVerifyMutatingWebhookConfiguration() error {
var caData []byte
var config *admregapi.MutatingWebhookConfiguration
// read CA data from
// 1) secret(config)
// 2) kubeconfig
if caData = wrc.readCaData(); caData == nil {
return errors.New("Unable to extract CA data from configuration")
}
// if serverIP is specified we assume its debug mode
if wrc.serverIP != "" {
// debug mode
// clientConfig - URL
config = wrc.constructDebugVerifyMutatingWebhookConfig(caData)
} else {
// clientConfig - service
config = wrc.constructVerifyMutatingWebhookConfig(caData)
}
// create mutating webhook configuration resource
if _, err := wrc.client.CreateResource(MutatingWebhookConfigurationKind, "", *config, false); err != nil {
return err
}
glog.V(4).Infof("created Mutating Webhook Configuration %s ", config.Name)
return nil
}
// DeregisterAll deletes webhook configs from cluster
// This function does not fail on error:
// Register will fail if the config exists, so there is no need to fail on error
func (wrc *WebhookRegistrationClient) removeWebhookConfigurations() {
startTime := time.Now()
glog.V(4).Infof("Started cleaning up webhookconfigurations")
defer func() {
glog.V(4).Infof("Finished cleaning up webhookcongfigurations (%v)", time.Since(startTime))
}()
var wg sync.WaitGroup
wg.Add(3)
// mutating and validating webhook configuration for Kubernetes resources
go wrc.removeResourceMutatingWebhookConfiguration(&wg)
// mutating and validating webhook configurtion for Policy CRD resource
go wrc.removePolicyMutatingWebhookConfiguration(&wg)
go wrc.removePolicyValidatingWebhookConfiguration(&wg)
// wait for the removal go routines to return
wg.Wait()
}
// wrapper to handle wait group
// TODO: re-work with RemoveResourceMutatingWebhookConfiguration, as the only difference is wg handling
func (wrc *WebhookRegistrationClient) removeResourceMutatingWebhookConfiguration(wg *sync.WaitGroup) {
defer wg.Done()
wrc.RemoveResourceMutatingWebhookConfiguration()
}
// delete policy mutating webhookconfigurations
// handle wait group
func (wrc *WebhookRegistrationClient) removePolicyMutatingWebhookConfiguration(wg *sync.WaitGroup) {
defer wg.Done()
// Mutating webhook configuration
var mutatingConfig string
if wrc.serverIP != "" {
mutatingConfig = config.PolicyMutatingWebhookConfigurationDebugName
} else {
mutatingConfig = config.PolicyMutatingWebhookConfigurationName
}
glog.V(4).Infof("removing webhook configuration %s", mutatingConfig)
err := wrc.registrationClient.MutatingWebhookConfigurations().Delete(mutatingConfig, &v1.DeleteOptions{})
if errorsapi.IsNotFound(err) {
glog.V(4).Infof("policy webhook configuration %s, does not exits. not deleting", mutatingConfig)
} else if err != nil {
glog.Errorf("failed to delete policy webhook configuration %s: %v", mutatingConfig, err)
} else {
glog.V(4).Infof("succesfully deleted policy webhook configuration %s", mutatingConfig)
}
}
// delete policy validating webhookconfigurations
// handle wait group
func (wrc *WebhookRegistrationClient) removePolicyValidatingWebhookConfiguration(wg *sync.WaitGroup) {
defer wg.Done()
// Validating webhook configuration
var err error
var validatingConfig string
if wrc.serverIP != "" {
validatingConfig = config.PolicyValidatingWebhookConfigurationDebugName
} else {
validatingConfig = config.PolicyValidatingWebhookConfigurationName
}
glog.V(4).Infof("removing webhook configuration %s", validatingConfig)
err = wrc.registrationClient.ValidatingWebhookConfigurations().Delete(validatingConfig, &v1.DeleteOptions{})
if errorsapi.IsNotFound(err) {
glog.V(4).Infof("policy webhook configuration %s, does not exits. not deleting", validatingConfig)
} else if err != nil {
glog.Errorf("failed to delete policy webhook configuration %s: %v", validatingConfig, err)
} else {
glog.V(4).Infof("succesfully deleted policy webhook configuration %s", validatingConfig)
}
}