Address comments.

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/server/testing/fake_cni_plugin.go

@@ -23,6 +23,7 @@ import (
 // FakeCNIPlugin is a fake plugin used for test.
 type FakeCNIPlugin struct {
 	StatusErr error
+	LoadErr   error
 }
 
 // NewFakeCNIPlugin create a FakeCNIPlugin.
@@ -47,5 +48,5 @@ func (f *FakeCNIPlugin) Status() error {
 
 // Load loads the network config.
 func (f *FakeCNIPlugin) Load(opts ...cni.LoadOption) error {
-	return nil
+	return f.LoadErr
 }

pkg/server/update_runtime_config.go

@@ -21,6 +21,7 @@ import (
 	"path/filepath"
 	"text/template"
 
+	cni "github.com/containerd/go-cni"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/net/context"
@@ -44,16 +45,17 @@ func (c *criService) UpdateRuntimeConfig(ctx context.Context, r *runtime.UpdateR
 		return &runtime.UpdateRuntimeConfigResponse{}, nil
 	}
 	confTemplate := c.config.NetworkPluginConfTemplate
-	if err := c.netPlugin.Status(); err == nil {
-		if confTemplate != "" {
-			logrus.Infof("Network plugin is ready, skip generating cni config from template %q", confTemplate)
-		}
-		return &runtime.UpdateRuntimeConfigResponse{}, nil
-	}
 	if confTemplate == "" {
 		logrus.Info("No cni config template is specified, wait for other system components to drop the config.")
 		return &runtime.UpdateRuntimeConfigResponse{}, nil
 	}
+	if err := c.netPlugin.Status(); err == nil {
+		logrus.Infof("Network plugin is ready, skip generating cni config from template %q", confTemplate)
+		return &runtime.UpdateRuntimeConfigResponse{}, nil
+	} else if err := c.netPlugin.Load(cni.WithLoNetwork(), cni.WithDefaultConf()); err == nil {
+		logrus.Infof("CNI config is successfully loaded, skip generating cni config from template %q", confTemplate)
+		return &runtime.UpdateRuntimeConfigResponse{}, nil
+	}
 	logrus.Infof("Generating cni config from template %q", confTemplate)
 	// generate cni config file from the template with updated pod cidr.
 	t, err := template.ParseFiles(confTemplate)

pkg/server/update_runtime_config_test.go

@@ -125,6 +125,7 @@ func TestUpdateRuntimeConfig(t *testing.T) {
 			}
 			if !test.networkReady {
 				c.netPlugin.(*servertesting.FakeCNIPlugin).StatusErr = errors.New("random error")
+				c.netPlugin.(*servertesting.FakeCNIPlugin).LoadErr = errors.New("random error")
 			}
 			_, err = c.UpdateRuntimeConfig(context.Background(), req)
 			assert.NoError(t, err)