feat(config): Add a new config for webhook (#980)

Signed-off-by: Ce Gao <gaoce@caicloud.io>

cmd/katib-controller/v1alpha3/main.go

@@ -40,18 +40,26 @@ func main() {
 	var experimentSuggestionName string
 	var metricsAddr string
 	var webhookPort int
+	var certLocalFS bool
 
 	flag.StringVar(&experimentSuggestionName, "experiment-suggestion-name",
 		"default", "The implementation of suggestion interface in experiment controller (default|fake)")
 	flag.StringVar(&metricsAddr, "metrics-addr", ":8080", "The address the metric endpoint binds to.")
 	flag.IntVar(&webhookPort, "webhook-port", 8443, "The port number to be used for admission webhook server.")
+	flag.BoolVar(&certLocalFS, "cert-localfs", false, "Store the webhook cert in local file system")
 
 	flag.Parse()
 
+	// Set the config in viper.
 	viper.Set(consts.ConfigExperimentSuggestionName, experimentSuggestionName)
+	viper.Set(consts.ConfigCertLocalFS, certLocalFS)
+
 	log.Info("Config:",
 		consts.ConfigExperimentSuggestionName,
-		viper.GetString(consts.ConfigExperimentSuggestionName))
+		viper.GetString(consts.ConfigExperimentSuggestionName),
+		consts.ConfigCertLocalFS,
+		viper.GetBool(consts.ConfigCertLocalFS),
+	)
 
 	// Get a config to talk to the apiserver
 	cfg, err := config.GetConfig()

pkg/controller.v1alpha3/consts/const.go

@@ -6,6 +6,9 @@ const (
 	// ConfigExperimentSuggestionName is the config name of the
 	// suggestion client implementation in experiment controller.
 	ConfigExperimentSuggestionName = "experiment-suggestion-name"
+	// ConfigCertLocalFS is the config name which indicates if we
+	// should store the cert in file system.
+	ConfigCertLocalFS = "cert-local-filesystem"
 
 	// LabelExperimentName is the label of experiment name.
 	LabelExperimentName = "experiment"

pkg/webhook/v1alpha3/webhook.go

@@ -16,6 +16,7 @@ limitations under the License.
 package webhook
 
 import (
+	"github.com/spf13/viper"
 	admissionregistrationv1beta1 "k8s.io/api/admissionregistration/v1beta1"
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -36,13 +37,9 @@ const (
 )
 
 func AddToManager(m manager.Manager, port int32) error {
-	server, err := webhook.NewServer("katib-admission-server", m, webhook.ServerOptions{
+	so := webhook.ServerOptions{
 		CertDir: "/tmp/cert",
 		BootstrapOptions: &webhook.BootstrapOptions{
-			Secret: &types.NamespacedName{
-				Namespace: consts.DefaultKatibNamespace,
-				Name:      katibControllerName,
-			},
 			Service: &webhook.Service{
 				Namespace: consts.DefaultKatibNamespace,
 				Name:      katibControllerName,
@@ -54,7 +51,18 @@ func AddToManager(m manager.Manager, port int32) error {
 			MutatingWebhookConfigName:   "katib-mutating-webhook-config",
 		},
 		Port: port,
-	})
+	}
+
+	// Decide if we should use local file system.
+	// If not, we set a secret in BootstrapOptions.
+	usingFS := viper.GetBool(consts.ConfigCertLocalFS)
+	if !usingFS {
+		so.BootstrapOptions.Secret = &types.NamespacedName{
+			Namespace: consts.DefaultKatibNamespace,
+			Name:      katibControllerName,
+		}
+	}
+	server, err := webhook.NewServer("katib-admission-server", m, so)
 	if err != nil {
 		return err
 	}