feat(volume): add remount read only volume grpc

ref: longhorn/longhorn 7843

Signed-off-by: Jack Lin <jack.lin@suse.com>

integration/rpc/proxy/github/com/longhorn/longhorn_instance_manager/pkg/imrpc/proxy_pb2_grpc.py

@@ -170,6 +170,11 @@ def __init__(self, channel):
                 request_serializer=github_dot_com_dot_longhorn_dot_longhorn__instance__manager_dot_pkg_dot_imrpc_dot_proxy__pb2.ProxyEngineRequest.SerializeToString,
                 response_deserializer=github_dot_com_dot_longhorn_dot_longhorn__instance__manager_dot_pkg_dot_imrpc_dot_proxy__pb2.EngineMetricsGetProxyResponse.FromString,
                 )
+        self.RemountReadOnlyVolume = channel.unary_unary(
+                '/imrpc.ProxyEngineService/RemountReadOnlyVolume',
+                request_serializer=github_dot_com_dot_longhorn_dot_longhorn__instance__manager_dot_pkg_dot_imrpc_dot_proxy__pb2.RemountVolumeRequest.SerializeToString,
+                response_deserializer=google_dot_protobuf_dot_empty__pb2.Empty.FromString,
+                )
 
 
 class ProxyEngineServiceServicer(object):
@@ -361,6 +366,12 @@ def MetricsGet(self, request, context):
         context.set_details('Method not implemented!')
         raise NotImplementedError('Method not implemented!')
 
+    def RemountReadOnlyVolume(self, request, context):
+        """Missing associated documentation comment in .proto file."""
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details('Method not implemented!')
+        raise NotImplementedError('Method not implemented!')
+
 
 def add_ProxyEngineServiceServicer_to_server(servicer, server):
     rpc_method_handlers = {
@@ -519,6 +530,11 @@ def add_ProxyEngineServiceServicer_to_server(servicer, server):
                     request_deserializer=github_dot_com_dot_longhorn_dot_longhorn__instance__manager_dot_pkg_dot_imrpc_dot_proxy__pb2.ProxyEngineRequest.FromString,
                     response_serializer=github_dot_com_dot_longhorn_dot_longhorn__instance__manager_dot_pkg_dot_imrpc_dot_proxy__pb2.EngineMetricsGetProxyResponse.SerializeToString,
             ),
+            'RemountReadOnlyVolume': grpc.unary_unary_rpc_method_handler(
+                    servicer.RemountReadOnlyVolume,
+                    request_deserializer=github_dot_com_dot_longhorn_dot_longhorn__instance__manager_dot_pkg_dot_imrpc_dot_proxy__pb2.RemountVolumeRequest.FromString,
+                    response_serializer=google_dot_protobuf_dot_empty__pb2.Empty.SerializeToString,
+            ),
     }
     generic_handler = grpc.method_handlers_generic_handler(
             'imrpc.ProxyEngineService', rpc_method_handlers)
@@ -1055,3 +1071,20 @@ def MetricsGet(request,
             github_dot_com_dot_longhorn_dot_longhorn__instance__manager_dot_pkg_dot_imrpc_dot_proxy__pb2.EngineMetricsGetProxyResponse.FromString,
             options, channel_credentials,
             insecure, call_credentials, compression, wait_for_ready, timeout, metadata)
+
+    @staticmethod
+    def RemountReadOnlyVolume(request,
+            target,
+            options=(),
+            channel_credentials=None,
+            call_credentials=None,
+            insecure=False,
+            compression=None,
+            wait_for_ready=None,
+            timeout=None,
+            metadata=None):
+        return grpc.experimental.unary_unary(request, target, '/imrpc.ProxyEngineService/RemountReadOnlyVolume',
+            github_dot_com_dot_longhorn_dot_longhorn__instance__manager_dot_pkg_dot_imrpc_dot_proxy__pb2.RemountVolumeRequest.SerializeToString,
+            google_dot_protobuf_dot_empty__pb2.Empty.FromString,
+            options, channel_credentials,
+            insecure, call_credentials, compression, wait_for_ready, timeout, metadata)

pkg/client/proxy_volume.go

@@ -296,3 +296,19 @@ func (c *ProxyClient) VolumeSnapshotMaxSizeSet(dataEngine, engineName, volumeNam
 
 	return nil
 }
+
+func (c *ProxyClient) RemountReadOnlyVolume(volumeName string) (err error) {
+	if volumeName == "" {
+		return fmt.Errorf("failed to remount volume, volume name is empty")
+	}
+
+	req := &rpc.RemountVolumeRequest{
+		VolumeName: volumeName,
+	}
+
+	_, err = c.service.RemountReadOnlyVolume(getContextWithGRPCTimeout(c.ctx), req)
+	if err != nil {
+		return err
+	}
+	return nil
+}

pkg/imrpc/proxy.proto

@@ -47,6 +47,7 @@ service ProxyEngineService {
 	rpc ReplicaModeUpdate(EngineReplicaModeUpdateRequest) returns (google.protobuf.Empty);
 
 	rpc MetricsGet(ProxyEngineRequest) returns (EngineMetricsGetProxyResponse);
+	rpc RemountReadOnlyVolume(RemountVolumeRequest) returns (google.protobuf.Empty);
 }
 
 message ProxyEngineRequest{
@@ -293,3 +294,7 @@ message EngineSnapshotHashStatusProxyResponse {
 message EngineMetricsGetProxyResponse {
 	ptypes.Metrics metrics = 1;
 }
+
+message RemountVolumeRequest {
+	string volume_name = 1;
+}

pkg/proxy/volume.go

@@ -1,17 +1,22 @@
 package proxy
 
 import (
+	"crypto/sha256"
+	"encoding/hex"
+
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/net/context"
 	grpccodes "google.golang.org/grpc/codes"
 	grpcstatus "google.golang.org/grpc/status"
 	"google.golang.org/protobuf/types/known/emptypb"
 
+	lhns "github.com/longhorn/go-common-libs/ns"
+	lhtypes "github.com/longhorn/go-common-libs/types"
 	eclient "github.com/longhorn/longhorn-engine/pkg/controller/client"
 	eptypes "github.com/longhorn/longhorn-engine/proto/ptypes"
-
 	rpc "github.com/longhorn/longhorn-instance-manager/pkg/imrpc"
+	"github.com/longhorn/longhorn-instance-manager/pkg/util"
 )
 
 func (p *Proxy) VolumeGet(ctx context.Context, req *rpc.ProxyEngineRequest) (resp *rpc.EngineVolumeGetProxyResponse, err error) {
@@ -308,3 +313,33 @@ func (ops V2DataEngineProxyOps) VolumeSnapshotMaxSizeSet(ctx context.Context, re
 	/* TODO: Implement this */
 	return &emptypb.Empty{}, nil
 }
+
+func (p *Proxy) RemountReadOnlyVolume(ctx context.Context, req *rpc.RemountVolumeRequest) (resp *emptypb.Empty, err error) {
+	volumeName := req.VolumeName
+	volumeNameSHA := sha256.Sum256([]byte(volumeName))
+	volumeNameSHAStr := hex.EncodeToString(volumeNameSHA[:])
+
+	volumeMountPointMap, err := util.GetVolumeMountPointMap()
+	if err != nil {
+		return &emptypb.Empty{}, err
+	}
+
+	namespaces := []lhtypes.Namespace{lhtypes.NamespaceMnt, lhtypes.NamespaceNet}
+	nsexec, err := lhns.NewNamespaceExecutor(lhtypes.ProcessNone, lhtypes.ProcDirectory, namespaces)
+	if err != nil {
+		return &emptypb.Empty{}, err
+	}
+
+	if mp, exists := volumeMountPointMap[volumeNameSHAStr]; exists {
+		opts := []string{
+			"-o",
+			"remount,rw",
+			mp.Path,
+		}
+		if _, err := nsexec.Execute("mount", opts, lhtypes.ExecuteDefaultTimeout); err != nil {
+			return nil, grpcstatus.Errorf(grpccodes.Internal, "remount failed with error: %v", err)
+		}
+	}
+
+	return &emptypb.Empty{}, nil
+}

pkg/types/types.go

@@ -44,7 +44,5 @@ const (
 )
 
 const (
-	GlobalMountPathPattern = "/host/var/lib/kubelet/plugins/kubernetes.io/csi/driver.longhorn.io/*/globalmount"
-
 	EngineConditionFilesystemReadOnly = "FilesystemReadOnly"
 )

pkg/util/util.go

@@ -7,7 +7,7 @@ import (
 	"net"
 	"os"
 	"os/exec"
-	"path"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -18,8 +18,6 @@ import (
 	"k8s.io/mount-utils"
 
 	spdkhelpertypes "github.com/longhorn/go-spdk-helper/pkg/types"
-
-	"github.com/longhorn/longhorn-instance-manager/pkg/types"
 )
 
 const (
@@ -158,12 +156,10 @@ func GetVolumeMountPointMap() (map[string]mount.MountPoint, error) {
 		return nil, err
 	}
 
+	regex := regexp.MustCompile(`.*/globalmount$`)
+
 	for _, mp := range mountPoints {
-		match, err := path.Match(types.GlobalMountPathPattern, mp.Path)
-		if err != nil {
-			return nil, err
-		}
-		if match {
+		if regex.MatchString(mp.Path) {
 			volumeNameSHAStr := GetVolumeNameSHAStrFromPath(mp.Path)
 			volumeMountPointMap[volumeNameSHAStr] = mp
 		}