CON-9040 driver can accidentally format existing volume

cmd/do-csi-plugin/Dockerfile

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM alpine:3.16
+FROM amd64/alpine:3.16
 
 # e2fsprogs-extra is required for resize2fs used for the resize operation
 # blkid: block device identification tool from util-linux

cmd/do-csi-plugin/main.go

@@ -40,6 +40,7 @@ func main() {
 		defaultVolumesPageSize = flag.Uint("default-volumes-page-size", 0, "The default page size used when paging through volumes results (default: do not specify and let the DO API choose)")
 		doAPIRateLimitQPS      = flag.Float64("do-api-rate-limit", 0, "Impose QPS rate limit on DigitalOcean API usage (default: do not rate limit)")
 		version                = flag.Bool("version", false, "Print the version and exit.")
+		validateAttachment     = flag.Bool("validate-attachment", false, "Validate if the attachment is in a running state.")
 	)
 	flag.Parse()
 
@@ -62,6 +63,7 @@ func main() {
 		DebugAddr:              *debugAddr,
 		DefaultVolumesPageSize: *defaultVolumesPageSize,
 		DOAPIRateLimitQPS:      *doAPIRateLimitQPS,
+		ValidateAttachment:     *validateAttachment,
 	})
 	if err != nil {
 		log.Fatalln(err)

driver/driver.go

@@ -68,6 +68,7 @@ type Driver struct {
 	doTag                  string
 	isController           bool
 	defaultVolumesPageSize uint
+	validateAttachment     bool
 
 	srv     *grpc.Server
 	httpSrv *http.Server
@@ -100,6 +101,7 @@ type NewDriverParams struct {
 	DebugAddr              string
 	DefaultVolumesPageSize uint
 	DOAPIRateLimitQPS      float64
+	ValidateAttachment     bool
 }
 
 // NewDriver returns a CSI plugin that contains the necessary gRPC

driver/driver_test.go

@@ -539,6 +539,10 @@ func (f *fakeMounter) GetDeviceName(_ mount.Interface, mountPath string) (string
 	return "", nil
 }
 
+func (f *fakeMounter) IsRunning(av iAttachmentValidator, source string) bool {
+	return true
+}
+
 func (f *fakeMounter) IsFormatted(source string) (bool, error) {
 	return true, nil
 }

driver/mockgen.go

@@ -0,0 +1,3 @@
+package driver
+
+//go:generate mockgen -source=mounter.go -destination=mounter_mock.go -package=driver

driver/mounter.go

@@ -33,6 +33,25 @@ import (
 	kexec "k8s.io/utils/exec"
 )
 
+const (
+	runningState = "running"
+)
+
+type attachmentValidator struct{}
+
+func (av *attachmentValidator) readFile(name string) ([]byte, error) {
+	return os.ReadFile(name)
+}
+
+func (av *attachmentValidator) evalSymlinks(path string) (string, error) {
+	return filepath.EvalSymlinks(path)
+}
+
+type iAttachmentValidator interface {
+	readFile(name string) ([]byte, error)
+	evalSymlinks(path string) (string, error)
+}
+
 type findmntResponse struct {
 	FileSystems []fileSystem `json:"filesystems"`
 }
@@ -67,6 +86,9 @@ type Mounter interface {
 	// Unmount unmounts the given target
 	Unmount(target string) error
 
+	// IsRunning checks whether the source device is in the running state.
+	IsRunning(av iAttachmentValidator, source string) bool
+
 	// IsFormatted checks whether the source device is formatted or not. It
 	// returns true if the source device is already formatted.
 	IsFormatted(source string) (bool, error)
@@ -208,6 +230,44 @@ func (m *mounter) Unmount(target string) error {
 	return mount.CleanupMountPoint(target, m.kMounter, true)
 }
 
+func (m *mounter) IsRunning(av iAttachmentValidator, source string) bool {
+	out, err := av.evalSymlinks(source)
+	if err != nil {
+		m.log.WithFields(logrus.Fields{
+			"source": source,
+		}).Errorf("error evaluating the sym link, err: %v", err)
+
+		return false
+	}
+
+	_, file := filepath.Split(out)
+	fileContent, err := av.readFile(fmt.Sprintf("/sys/class/block/%s/device/state", file))
+	if err != nil {
+		m.log.WithFields(logrus.Fields{
+			"source": source,
+			"file":   file,
+		}).Errorf("error reading the device state file, err: %v", err)
+
+		return false
+	}
+
+	m.log.WithFields(logrus.Fields{
+		"source":      source,
+		"fileContent": string(fileContent),
+	}).Info("state file content")
+
+	if string(fileContent) != fmt.Sprintf("%s\n", runningState) {
+		m.log.WithFields(logrus.Fields{
+			"source":      source,
+			"fileContent": string(fileContent),
+		}).Error("the state file does not specify the running state")
+
+		return false
+	}
+
+	return true
+}
+
 func (m *mounter) IsFormatted(source string) (bool, error) {
 	if source == "" {
 		return false, errors.New("source is not specified")