Add external-snapshotter to ceph-csi

Adding extenal-provisoner will help us to
test snapshot functionality

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/github.com/prometheus/procfs/mdstat.go

@@ -42,64 +42,64 @@ type MDStat struct {
 	BlocksSynced int64
 }
 
-// ParseMDStat parses an mdstat-file and returns a struct with the relevant infos.
-func (fs FS) ParseMDStat() (mdstates []MDStat, err error) {
-	mdStatusFilePath := fs.proc.Path("mdstat")
-	content, err := ioutil.ReadFile(mdStatusFilePath)
+// MDStat parses an mdstat-file (/proc/mdstat) and returns a slice of
+// structs containing the relevant info.  More information available here:
+// https://raid.wiki.kernel.org/index.php/Mdstat
+func (fs FS) MDStat() ([]MDStat, error) {
+	data, err := ioutil.ReadFile(fs.proc.Path("mdstat"))
 	if err != nil {
-		return []MDStat{}, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+		return nil, fmt.Errorf("error parsing mdstat %s: %s", fs.proc.Path("mdstat"), err)
 	}
+	mdstat, err := parseMDStat(data)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing mdstat %s: %s", fs.proc.Path("mdstat"), err)
+	}
+	return mdstat, nil
+}
 
-	mdStates := []MDStat{}
-	lines := strings.Split(string(content), "\n")
+// parseMDStat parses data from mdstat file (/proc/mdstat) and returns a slice of
+// structs containing the relevant info.
+func parseMDStat(mdstatData []byte) ([]MDStat, error) {
+	mdStats := []MDStat{}
+	lines := strings.Split(string(mdstatData), "\n")
 	for i, l := range lines {
-		if l == "" {
-			continue
-		}
-		if l[0] == ' ' {
-			continue
-		}
-		if strings.HasPrefix(l, "Personalities") || strings.HasPrefix(l, "unused") {
+		if strings.TrimSpace(l) == "" || l[0] == ' ' ||
+			strings.HasPrefix(l, "Personalities") || strings.HasPrefix(l, "unused") {
 			continue
 		}
 
-		mainLine := strings.Split(l, " ")
-		if len(mainLine) < 3 {
-			return mdStates, fmt.Errorf("error parsing mdline: %s", l)
+		deviceFields := strings.Fields(l)
+		if len(deviceFields) < 3 {
+			return nil, fmt.Errorf("not enough fields in mdline (expected at least 3): %s", l)
 		}
-		mdName := mainLine[0]
-		activityState := mainLine[2]
+		mdName := deviceFields[0]
+		activityState := deviceFields[2]
 
 		if len(lines) <= i+3 {
-			return mdStates, fmt.Errorf(
-				"error parsing %s: too few lines for md device %s",
-				mdStatusFilePath,
-				mdName,
-			)
+			return mdStats, fmt.Errorf("missing lines for md device %s", mdName)
 		}
 
-		active, total, size, err := evalStatusline(lines[i+1])
+		active, total, size, err := evalStatusLine(lines[i+1])
 		if err != nil {
-			return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+			return nil, err
 		}
 
-		// j is the line number of the syncing-line.
-		j := i + 2
+		syncLineIdx := i + 2
 		if strings.Contains(lines[i+2], "bitmap") { // skip bitmap line
-			j = i + 3
+			syncLineIdx++
 		}
 
-		// If device is syncing at the moment, get the number of currently
+		// If device is recovering/syncing at the moment, get the number of currently
 		// synced bytes, otherwise that number equals the size of the device.
 		syncedBlocks := size
-		if strings.Contains(lines[j], "recovery") || strings.Contains(lines[j], "resync") {
-			syncedBlocks, err = evalBuildline(lines[j])
+		if strings.Contains(lines[syncLineIdx], "recovery") || strings.Contains(lines[syncLineIdx], "resync") {
+			syncedBlocks, err = evalRecoveryLine(lines[syncLineIdx])
 			if err != nil {
-				return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+				return nil, err
 			}
 		}
 
-		mdStates = append(mdStates, MDStat{
+		mdStats = append(mdStats, MDStat{
 			Name:          mdName,
 			ActivityState: activityState,
 			DisksActive:   active,
@@ -109,10 +109,10 @@ func (fs FS) ParseMDStat() (mdstates []MDStat, err error) {
 		})
 	}
 
-	return mdStates, nil
+	return mdStats, nil
 }
 
-func evalStatusline(statusline string) (active, total, size int64, err error) {
+func evalStatusLine(statusline string) (active, total, size int64, err error) {
 	matches := statuslineRE.FindStringSubmatch(statusline)
 	if len(matches) != 4 {
 		return 0, 0, 0, fmt.Errorf("unexpected statusline: %s", statusline)
@@ -136,7 +136,7 @@ func evalStatusline(statusline string) (active, total, size int64, err error) {
 	return active, total, size, nil
 }
 
-func evalBuildline(buildline string) (syncedBlocks int64, err error) {
+func evalRecoveryLine(buildline string) (syncedBlocks int64, err error) {
 	matches := buildlineRE.FindStringSubmatch(buildline)
 	if len(matches) != 2 {
 		return 0, fmt.Errorf("unexpected buildline: %s", buildline)