adding support for expanding in use persistent volumes for Flex

pkg/volume/flexvolume/expander.go

@@ -0,0 +1,67 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package flexvolume
+
+import (
+	"fmt"
+	"k8s.io/apimachinery/pkg/api/resource"
+	"k8s.io/kubernetes/pkg/volume"
+	"strconv"
+)
+
+func (plugin *flexVolumePlugin) ExpandVolumeDevice(spec *volume.Spec, newSize resource.Quantity, oldSize resource.Quantity) (resource.Quantity, error) {
+	call := plugin.NewDriverCall(expandVolumeCmd)
+	call.AppendSpec(spec, plugin.host, nil)
+
+	devicePath, err := plugin.getDeviceMountPath(spec)
+	if err != nil {
+		return newSize, err
+	}
+	call.Append(devicePath)
+	call.Append(strconv.FormatInt(newSize.Value(), 10))
+	call.Append(strconv.FormatInt(oldSize.Value(), 10))
+
+	_, err = call.Run()
+	if isCmdNotSupportedErr(err) {
+		return newExpanderDefaults(plugin).ExpandVolumeDevice(spec, newSize, oldSize)
+	}
+	return newSize, err
+}
+
+func (plugin *flexVolumePlugin) ExpandFS(spec *volume.Spec, devicePath, deviceMountPath string, newSize, oldSize resource.Quantity) error {
+	// This method is called after we spec.PersistentVolume.Spec.Capacity
+	// has been updated to the new size. The underlying driver thus sees
+	// the _new_ (requested) size and can find out the _current_ size from
+	// its underlying storage implementation
+
+	if spec.PersistentVolume == nil {
+		return fmt.Errorf("PersistentVolume not found for spec: %s", spec.Name())
+	}
+
+	call := plugin.NewDriverCall(expandFSCmd)
+	call.AppendSpec(spec, plugin.host, nil)
+	call.Append(devicePath)
+	call.Append(deviceMountPath)
+	call.Append(strconv.FormatInt(newSize.Value(), 10))
+	call.Append(strconv.FormatInt(oldSize.Value(), 10))
+
+	_, err := call.Run()
+	if isCmdNotSupportedErr(err) {
+		return newExpanderDefaults(plugin).ExpandFS(spec, devicePath, deviceMountPath, newSize, oldSize)
+	}
+	return err
+}