issue #91

issue #217

Goal

we try to solve when csi exit unexpect, the pod use cephfs pv can not auto recovery because lost mount relation until pod be killed and reschedule to other node. i think this is may be a problem. may be csi plugin can do more thing to remount the old path so when pod may be auto recovery when pod exit and restart, the old mount path can use.

NoGoal

Pod should exit and restart when csi plugin pod exit and mount point lost. if pod not exit will get error of **transport endpoint is not connected**.

implment logic

csi-plugin start:

	1. load all MountCachEntry  from node local dir
	2. check if volID exist in cluster, if no we ignore this entry, if yes continue
	3. check if stagingPath exist, if yes we mount the path
	4. check if all targetPath exist, if yes we binmount to staging path

NodeServer:

1. NodeStageVolume: add MountCachEntry on local dir include readonly attr and ceph secret
2. NodeStagePublishVolume: add pod bind mount path to MountCachEntry  and persist local dir
3. NodeStageunPublishVolume: remove pod bind mount path From MountCachEntry  and persist local dir
4. NodeStageunStageVolume: remove MountCachEntry  from local dir

pkg/util/cachepersister.go

@@ -56,6 +56,7 @@ func NewCachePersister(metadataStore, driverName string) (CachePersister, error)
 		klog.Infof("cache-persister: using node as metadata cache persister")
 		nc := &NodeCache{}
 		nc.BasePath = PluginFolder + "/" + driverName
+		nc.CacheDir = "controller"
 		return nc, nil
 	}
 	return nil, errors.New("cache-persister: couldn't parse metadatastorage flag")

pkg/util/nodecache.go

@@ -32,10 +32,9 @@ import (
 // NodeCache to store metadata
 type NodeCache struct {
 	BasePath string
+	CacheDir string
 }
 
-var cacheDir = "controller"
-
 var errDec = errors.New("file not found")
 
 // EnsureCacheDirectory creates cache directory if not present
@@ -52,15 +51,15 @@ func (nc *NodeCache) EnsureCacheDirectory(cacheDir string) error {
 
 //ForAll list the metadata in Nodecache and filters outs based on the pattern
 func (nc *NodeCache) ForAll(pattern string, destObj interface{}, f ForAllFunc) error {
-	err := nc.EnsureCacheDirectory(cacheDir)
+	err := nc.EnsureCacheDirectory(nc.CacheDir)
 	if err != nil {
 		return errors.Wrap(err, "node-cache: couldn't ensure cache directory exists")
 	}
-	files, err := ioutil.ReadDir(path.Join(nc.BasePath, cacheDir))
+	files, err := ioutil.ReadDir(path.Join(nc.BasePath, nc.CacheDir))
 	if err != nil {
 		return errors.Wrapf(err, "node-cache: failed to read %s folder", nc.BasePath)
 	}
-	path := path.Join(nc.BasePath, cacheDir)
+	path := path.Join(nc.BasePath, nc.CacheDir)
 	for _, file := range files {
 		err = decodeObj(path, pattern, file, destObj)
 		if err == errDec {
@@ -102,9 +101,23 @@ func decodeObj(filepath, pattern string, file os.FileInfo, destObj interface{})
 
 }
 
+func (nc *NodeCache) Update(identifier string, data interface{}) error {
+	file := path.Join(nc.BasePath, nc.CacheDir, identifier+".json")
+	identifierTmp := identifier + ".creating"
+	fileTmp := path.Join(nc.BasePath, nc.CacheDir, identifierTmp+".json")
+	os.Remove(fileTmp)
+	if err := nc.Create(identifierTmp, data); err != nil {
+		return errors.Wrapf(err, "node-cache: failed to create metadata storage file %s\n", file)
+	}
+	if err := os.Rename(fileTmp, file); err != nil {
+		return errors.Wrapf(err, "node-cache: couldn't rename %s as %s", fileTmp, file)
+	}
+	return nil
+}
+
 // Create creates the metadata file in cache directory with identifier name
 func (nc *NodeCache) Create(identifier string, data interface{}) error {
-	file := path.Join(nc.BasePath, cacheDir, identifier+".json")
+	file := path.Join(nc.BasePath, nc.CacheDir, identifier+".json")
 	fp, err := os.Create(file)
 	if err != nil {
 		return errors.Wrapf(err, "node-cache: failed to create metadata storage file %s\n", file)
@@ -126,7 +139,7 @@ func (nc *NodeCache) Create(identifier string, data interface{}) error {
 
 // Get retrieves the metadata from cache directory with identifier name
 func (nc *NodeCache) Get(identifier string, data interface{}) error {
-	file := path.Join(nc.BasePath, cacheDir, identifier+".json")
+	file := path.Join(nc.BasePath, nc.CacheDir, identifier+".json")
 	// #nosec
 	fp, err := os.Open(file)
 	if err != nil {
@@ -153,7 +166,7 @@ func (nc *NodeCache) Get(identifier string, data interface{}) error {
 
 // Delete deletes the metadata file from cache directory with identifier name
 func (nc *NodeCache) Delete(identifier string) error {
-	file := path.Join(nc.BasePath, cacheDir, identifier+".json")
+	file := path.Join(nc.BasePath, nc.CacheDir, identifier+".json")
 	err := os.Remove(file)
 	if err != nil {
 		if err == os.ErrNotExist {