Detect peer reboots to invalidate current storage REST clients (#7227)

cmd/storage-rest-client.go

@@ -43,11 +43,13 @@ import (
 // data for all internode storage REST requests.
 const storageRESTTimeout = 5 * time.Minute
 
-func isNetworkDisconnectError(err error) bool {
+func isNetworkError(err error) bool {
 	if err == nil {
 		return false
 	}
-
+	if err.Error() == errConnectionStale.Error() {
+		return true
+	}
 	if uerr, isURLError := err.(*url.Error); isURLError {
 		if uerr.Timeout() {
 			return true
@@ -68,7 +70,7 @@ func toStorageErr(err error) error {
 		return nil
 	}
 
-	if isNetworkDisconnectError(err) {
+	if isNetworkError(err) {
 		return errDiskNotFound
 	}
 
@@ -128,6 +130,7 @@ type storageRESTClient struct {
 	restClient *rest.Client
 	connected  bool
 	lastError  error
+	instanceID string // REST server's instanceID which is sent with every request for validation.
 }
 
 // Wrapper to restClient.Call to handle network errors, in case of network error the connection is makred disconnected
@@ -137,12 +140,16 @@ func (client *storageRESTClient) call(method string, values url.Values, body io.
 	if !client.connected {
 		return nil, errDiskNotFound
 	}
+	if values == nil {
+		values = make(url.Values)
+	}
+	values.Set(storageRESTInstanceID, client.instanceID)
 	respBody, err = client.restClient.Call(method, values, body, length)
 	if err == nil {
 		return respBody, nil
 	}
 	client.lastError = err
-	if isNetworkDisconnectError(err) {
+	if isNetworkError(err) {
 		client.connected = false
 	}
 
@@ -350,6 +357,22 @@ func (client *storageRESTClient) RenameFile(srcVolume, srcPath, dstVolume, dstPa
 	return err
 }
 
+// Gets peer storage server's instanceID - to be used with every REST call for validation.
+func (client *storageRESTClient) getInstanceID() (err error) {
+	respBody, err := client.restClient.Call(storageRESTMethodGetInstanceID, nil, nil, -1)
+	if err != nil {
+		return err
+	}
+	defer http.DrainBody(respBody)
+	instanceIDBuf := make([]byte, 64)
+	n, err := io.ReadFull(respBody, instanceIDBuf)
+	if err != io.EOF && err != io.ErrUnexpectedEOF {
+		return err
+	}
+	client.instanceID = string(instanceIDBuf[:n])
+	return nil
+}
+
 // Close - marks the client as closed.
 func (client *storageRESTClient) Close() error {
 	client.connected = false
@@ -382,5 +405,7 @@ func newStorageRESTClient(endpoint Endpoint) *storageRESTClient {
 	}
 
 	restClient := rest.NewClient(serverURL, tlsConfig, storageRESTTimeout, newAuthToken)
-	return &storageRESTClient{endpoint: endpoint, restClient: restClient, connected: true}
+	client := &storageRESTClient{endpoint: endpoint, restClient: restClient, connected: true}
+	client.connected = client.getInstanceID() == nil
+	return client
 }

cmd/storage-rest-common.go

@@ -36,6 +36,7 @@ const (
 	storageRESTMethodListDir        = "listdir"
 	storageRESTMethodDeleteFile     = "deletefile"
 	storageRESTMethodRenameFile     = "renamefile"
+	storageRESTMethodGetInstanceID  = "getinstanceid"
 )
 
 const (
@@ -51,4 +52,5 @@ const (
 	storageRESTCount      = "count"
 	storageRESTBitrotAlgo = "bitrot-algo"
 	storageRESTBitrotHash = "bitrot-hash"
+	storageRESTInstanceID = "instance-id"
 )

cmd/storage-rest-server.go

@@ -17,6 +17,7 @@
 package cmd
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"path"
@@ -33,9 +34,14 @@ import (
 	"github.com/minio/minio/cmd/logger"
 )
 
+var errConnectionStale = errors.New("connection stale, REST client/server instance-id mismatch")
+
 // To abstract a disk over network.
 type storageRESTServer struct {
 	storage *posix
+	// Used to detect reboot of servers so that peers revalidate format.json as
+	// different disk might be available on the same mount point after reboot.
+	instanceID string
 }
 
 func (s *storageRESTServer) writeErrorResponse(w http.ResponseWriter, err error) {
@@ -43,23 +49,15 @@ func (s *storageRESTServer) writeErrorResponse(w http.ResponseWriter, err error)
 	w.Write([]byte(err.Error()))
 }
 
-// Authenticates storage client's requests.
-func storageServerRequestAuthenticate(r *http.Request) error {
-	_, _, err := webRequestAuthenticate(r)
+// Authenticates storage client's requests and validates for skewed time.
+func storageServerRequestValidate(r *http.Request) error {
+	if _, _, err := webRequestAuthenticate(r); err != nil {
 		return err
 	}
-
-// IsValid - To authenticate and verify the time difference.
-func (s *storageRESTServer) IsValid(w http.ResponseWriter, r *http.Request) bool {
-	if err := storageServerRequestAuthenticate(r); err != nil {
-		w.WriteHeader(http.StatusForbidden)
-		return false
-	}
 	requestTimeStr := r.Header.Get("X-Minio-Time")
 	requestTime, err := time.Parse(time.RFC3339, requestTimeStr)
 	if err != nil {
-		s.writeErrorResponse(w, err)
-		return false
+		return err
 	}
 	utcNow := UTCNow()
 	delta := requestTime.Sub(utcNow)
@@ -67,12 +65,36 @@ func (s *storageRESTServer) IsValid(w http.ResponseWriter, r *http.Request) bool
 		delta = delta * -1
 	}
 	if delta > DefaultSkewTime {
-		s.writeErrorResponse(w, fmt.Errorf("client time %v is too apart with server time %v", requestTime, utcNow))
+		return fmt.Errorf("client time %v is too apart with server time %v", requestTime, utcNow)
+	}
+	return nil
+}
+
+// IsValid - To authenticate and verify the time difference.
+func (s *storageRESTServer) IsValid(w http.ResponseWriter, r *http.Request) bool {
+	if err := storageServerRequestValidate(r); err != nil {
+		s.writeErrorResponse(w, err)
+		return false
+	}
+	instanceID := r.URL.Query().Get(storageRESTInstanceID)
+	if instanceID != s.instanceID {
+		// This will cause the peer to revalidate format.json using a new storage-rest-client instance.
+		s.writeErrorResponse(w, errConnectionStale)
 		return false
 	}
 	return true
 }
 
+// GetInstanceID - returns the instance ID of the server.
+func (s *storageRESTServer) GetInstanceID(w http.ResponseWriter, r *http.Request) {
+	if err := storageServerRequestValidate(r); err != nil {
+		s.writeErrorResponse(w, err)
+		return
+	}
+	w.Header().Set("Content-Length", strconv.Itoa(len(s.instanceID)))
+	w.Write([]byte(s.instanceID))
+}
+
 // DiskInfoHandler - returns disk info.
 func (s *storageRESTServer) DiskInfoHandler(w http.ResponseWriter, r *http.Request) {
 	if !s.IsValid(w, r) {
@@ -383,7 +405,7 @@ func registerStorageRESTHandlers(router *mux.Router, endpoints EndpointList) {
 			logger.Fatal(uiErrUnableToWriteInBackend(err), "Unable to initialize posix backend")
 		}
 
-		server := &storageRESTServer{storage}
+		server := &storageRESTServer{storage, mustGetUUID()}
 
 		subrouter := router.PathPrefix(path.Join(storageRESTPath, endpoint.Path)).Subrouter()
 
@@ -414,6 +436,7 @@ func registerStorageRESTHandlers(router *mux.Router, endpoints EndpointList) {
 			Queries(restQueries(storageRESTVolume, storageRESTFilePath)...)
 		subrouter.Methods(http.MethodPost).Path("/" + storageRESTMethodRenameFile).HandlerFunc(httpTraceHdrs(server.RenameFileHandler)).
 			Queries(restQueries(storageRESTSrcVolume, storageRESTSrcPath, storageRESTDstVolume, storageRESTDstPath)...)
+		subrouter.Methods(http.MethodPost).Path("/" + storageRESTMethodGetInstanceID).HandlerFunc(httpTraceAll(server.GetInstanceID))
 	}
 
 	router.NotFoundHandler = http.HandlerFunc(httpTraceAll(notFoundHandler))