Adding dynamic Flexvolume plugin discovery capability, using filesystem watch.

cmd/kube-controller-manager/app/plugins.go

@@ -60,18 +60,15 @@ import (
 )
 
 // ProbeAttachableVolumePlugins collects all volume plugins for the attach/
-// detach controller. VolumeConfiguration is used ot get FlexVolumePluginDir
-// which specifies the directory to search for additional third party volume
-// plugins.
+// detach controller.
 // The list of plugins is manually compiled. This code and the plugin
 // initialization code for kubelet really, really need a through refactor.
-func ProbeAttachableVolumePlugins(config componentconfig.VolumeConfiguration) []volume.VolumePlugin {
+func ProbeAttachableVolumePlugins() []volume.VolumePlugin {
 	allPlugins := []volume.VolumePlugin{}
 
 	allPlugins = append(allPlugins, aws_ebs.ProbeVolumePlugins()...)
 	allPlugins = append(allPlugins, gce_pd.ProbeVolumePlugins()...)
 	allPlugins = append(allPlugins, cinder.ProbeVolumePlugins()...)
-	allPlugins = append(allPlugins, flexvolume.ProbeVolumePlugins(config.FlexVolumePluginDir)...)
 	allPlugins = append(allPlugins, portworx.ProbeVolumePlugins()...)
 	allPlugins = append(allPlugins, vsphere_volume.ProbeVolumePlugins()...)
 	allPlugins = append(allPlugins, azure_dd.ProbeVolumePlugins()...)
@@ -82,6 +79,13 @@ func ProbeAttachableVolumePlugins(config componentconfig.VolumeConfiguration) []
 	return allPlugins
 }
 
+// GetDynamicPluginProber gets the probers of dynamically discoverable plugins
+// for the attach/detach controller.
+// Currently only Flexvolume plugins are dynamically discoverable.
+func GetDynamicPluginProber(config componentconfig.VolumeConfiguration) volume.DynamicPluginProber {
+	return flexvolume.GetDynamicPluginProber(config.FlexVolumePluginDir)
+}
+
 // ProbeControllerVolumePlugins collects all persistent volume plugins into an
 // easy to use list. Only volume plugins that implement any of
 // provisioner/recycler/deleter interface should be returned.