nfs: add nodeserver within cephcsi

This commit adds nfs nodeserver capable of
mounting nfs volumes, even with pod networking
using NSenter design similar to rbd and cephfs.
NodePublish, NodeUnpublish, NodeGetVolumeStats
and NodeGetCapabilities have been implemented.

The nodeserver implementation has been inspired
from https://github.com/kubernetes-csi/csi-driver-nfs,
which was previously used for mounted cephcsi exported
nfs volumes. The current implementation is also
backward compatible for the previously created
PVCs.

Signed-off-by: Rakshith R <rar@redhat.com>

internal/csi-common/nodeserver-default.go

@@ -29,6 +29,7 @@ import (
 
 // DefaultNodeServer stores driver object.
 type DefaultNodeServer struct {
+	csi.UnimplementedNodeServer
 	Driver  *CSIDriver
 	Type    string
 	Mounter mount.Interface

internal/nfs/driver/driver.go

@@ -20,6 +20,7 @@ import (
 	csicommon "github.com/ceph/ceph-csi/internal/csi-common"
 	"github.com/ceph/ceph-csi/internal/nfs/controller"
 	"github.com/ceph/ceph-csi/internal/nfs/identity"
+	"github.com/ceph/ceph-csi/internal/nfs/nodeserver"
 	"github.com/ceph/ceph-csi/internal/util"
 	"github.com/ceph/ceph-csi/internal/util/log"
 
@@ -43,27 +44,39 @@ func (fs *Driver) Run(conf *util.Config) {
 		log.FatalLogMsg("failed to initialize CSI driver")
 	}
 
-	cd.AddControllerServiceCapabilities([]csi.ControllerServiceCapability_RPC_Type{
-		csi.ControllerServiceCapability_RPC_CREATE_DELETE_VOLUME,
-		csi.ControllerServiceCapability_RPC_SINGLE_NODE_MULTI_WRITER,
-		csi.ControllerServiceCapability_RPC_EXPAND_VOLUME,
-		csi.ControllerServiceCapability_RPC_CREATE_DELETE_SNAPSHOT,
-		csi.ControllerServiceCapability_RPC_CLONE_VOLUME,
-	})
-	// VolumeCapabilities are validated by the CephFS Controller
-	cd.AddVolumeCapabilityAccessModes([]csi.VolumeCapability_AccessMode_Mode{
-		csi.VolumeCapability_AccessMode_MULTI_NODE_MULTI_WRITER,
-		csi.VolumeCapability_AccessMode_SINGLE_NODE_WRITER,
-		csi.VolumeCapability_AccessMode_SINGLE_NODE_MULTI_WRITER,
-		csi.VolumeCapability_AccessMode_SINGLE_NODE_SINGLE_WRITER,
-	})
+	if conf.IsControllerServer || !conf.IsNodeServer {
+		cd.AddControllerServiceCapabilities([]csi.ControllerServiceCapability_RPC_Type{
+			csi.ControllerServiceCapability_RPC_CREATE_DELETE_VOLUME,
+			csi.ControllerServiceCapability_RPC_SINGLE_NODE_MULTI_WRITER,
+			csi.ControllerServiceCapability_RPC_EXPAND_VOLUME,
+			csi.ControllerServiceCapability_RPC_CREATE_DELETE_SNAPSHOT,
+			csi.ControllerServiceCapability_RPC_CLONE_VOLUME,
+		})
+		// VolumeCapabilities are validated by the CephFS Controller
+		cd.AddVolumeCapabilityAccessModes([]csi.VolumeCapability_AccessMode_Mode{
+			csi.VolumeCapability_AccessMode_MULTI_NODE_MULTI_WRITER,
+			csi.VolumeCapability_AccessMode_SINGLE_NODE_WRITER,
+			csi.VolumeCapability_AccessMode_SINGLE_NODE_MULTI_WRITER,
+			csi.VolumeCapability_AccessMode_SINGLE_NODE_SINGLE_WRITER,
+		})
+	}
 
 	// Create gRPC servers
 	server := csicommon.NewNonBlockingGRPCServer()
 	srv := csicommon.Servers{
 		IS: identity.NewIdentityServer(cd),
-		CS: controller.NewControllerServer(cd),
 	}
+
+	switch {
+	case conf.IsNodeServer:
+		srv.NS = nodeserver.NewNodeServer(cd, conf.Vtype)
+	case conf.IsControllerServer:
+		srv.CS = controller.NewControllerServer(cd)
+	default:
+		srv.NS = nodeserver.NewNodeServer(cd, conf.Vtype)
+		srv.CS = controller.NewControllerServer(cd)
+	}
+
 	server.Start(conf.Endpoint, conf.HistogramOption, srv, conf.EnableGRPCMetrics)
 	if conf.EnableGRPCMetrics {
 		log.WarningLogMsg("EnableGRPCMetrics is deprecated")

internal/nfs/nodeserver/nodeserver.go

@@ -0,0 +1,284 @@
+/*
+Copyright 2022 The Ceph-CSI Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package nodeserver
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	csicommon "github.com/ceph/ceph-csi/internal/csi-common"
+	"github.com/ceph/ceph-csi/internal/util"
+	"github.com/ceph/ceph-csi/internal/util/log"
+
+	"github.com/container-storage-interface/spec/lib/go/csi"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	mount "k8s.io/mount-utils"
+	netutil "k8s.io/utils/net"
+)
+
+const (
+	defaultMountPermission = os.FileMode(0o777)
+	// Address of the NFS server.
+	paramServer    = "server"
+	paramShare     = "share"
+	paramClusterID = "clusterID"
+)
+
+// NodeServer struct of ceph CSI driver with supported methods of CSI
+// node server spec.
+type NodeServer struct {
+	csicommon.DefaultNodeServer
+}
+
+// NewNodeServer initialize a node server for ceph CSI driver.
+func NewNodeServer(
+	d *csicommon.CSIDriver,
+	t string,
+) *NodeServer {
+	return &NodeServer{
+		DefaultNodeServer: *csicommon.NewDefaultNodeServer(d, t, map[string]string{}),
+	}
+}
+
+// NodePublishVolume mount the volume.
+func (ns *NodeServer) NodePublishVolume(
+	ctx context.Context,
+	req *csi.NodePublishVolumeRequest,
+) (*csi.NodePublishVolumeResponse, error) {
+	err := validateNodePublishVolumeRequest(req)
+	if err != nil {
+		return nil, status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	volumeID := req.GetVolumeId()
+	volCap := req.GetVolumeCapability()
+	targetPath := req.GetTargetPath()
+	mountOptions := volCap.GetMount().GetMountFlags()
+	if req.GetReadonly() {
+		mountOptions = append(mountOptions, "ro")
+	}
+
+	source, err := getSource(req.GetVolumeContext())
+	if err != nil {
+		return nil, status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	clusterID := req.GetVolumeContext()[paramClusterID]
+	netNamespaceFilePath := ""
+	if clusterID != "" {
+		netNamespaceFilePath, err = util.GetNFSNetNamespaceFilePath(
+			util.CsiConfigFile,
+			clusterID)
+		if err != nil {
+			return nil, status.Error(codes.Internal, err.Error())
+		}
+	}
+
+	err = ns.mountNFS(ctx,
+		volumeID,
+		source,
+		targetPath,
+		netNamespaceFilePath,
+		mountOptions)
+	if err != nil {
+		if os.IsPermission(err) {
+			return nil, status.Error(codes.PermissionDenied, err.Error())
+		}
+		if strings.Contains(err.Error(), "invalid argument") {
+			return nil, status.Error(codes.InvalidArgument, err.Error())
+		}
+
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+	log.DebugLog(ctx, "nfs: successfully mounted volume %q mount %q to %q succeeded",
+		volumeID, source, targetPath)
+
+	return &csi.NodePublishVolumeResponse{}, nil
+}
+
+// NodeUnpublishVolume unmount the volume.
+func (ns *NodeServer) NodeUnpublishVolume(
+	ctx context.Context,
+	req *csi.NodeUnpublishVolumeRequest,
+) (*csi.NodeUnpublishVolumeResponse, error) {
+	err := util.ValidateNodeUnpublishVolumeRequest(req)
+	if err != nil {
+		return nil, err
+	}
+
+	volumeID := req.GetVolumeId()
+	targetPath := req.GetTargetPath()
+	log.DebugLog(ctx, "nfs: unmounting volume %s on %s", volumeID, targetPath)
+	err = mount.CleanupMountPoint(targetPath, ns.Mounter, true)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "failed to unmount target %q: %v",
+			targetPath, err)
+	}
+	log.DebugLog(ctx, "nfs: successfully unbounded volume %q from %q",
+		volumeID, targetPath)
+
+	return &csi.NodeUnpublishVolumeResponse{}, nil
+}
+
+// NodeGetCapabilities returns the supported capabilities of the node server.
+func (ns *NodeServer) NodeGetCapabilities(
+	ctx context.Context,
+	req *csi.NodeGetCapabilitiesRequest,
+) (*csi.NodeGetCapabilitiesResponse, error) {
+	return &csi.NodeGetCapabilitiesResponse{
+		Capabilities: []*csi.NodeServiceCapability{
+			{
+				Type: &csi.NodeServiceCapability_Rpc{
+					Rpc: &csi.NodeServiceCapability_RPC{
+						Type: csi.NodeServiceCapability_RPC_GET_VOLUME_STATS,
+					},
+				},
+			},
+			{
+				Type: &csi.NodeServiceCapability_Rpc{
+					Rpc: &csi.NodeServiceCapability_RPC{
+						Type: csi.NodeServiceCapability_RPC_SINGLE_NODE_MULTI_WRITER,
+					},
+				},
+			},
+		},
+	}, nil
+}
+
+// NodeGetVolumeStats get volume stats.
+func (ns *NodeServer) NodeGetVolumeStats(
+	ctx context.Context,
+	req *csi.NodeGetVolumeStatsRequest,
+) (*csi.NodeGetVolumeStatsResponse, error) {
+	var err error
+	targetPath := req.GetVolumePath()
+	if targetPath == "" {
+		return nil, status.Error(codes.InvalidArgument,
+			fmt.Sprintf("targetpath %v is empty", targetPath))
+	}
+
+	stat, err := os.Stat(targetPath)
+	if err != nil {
+		return nil, status.Errorf(codes.InvalidArgument,
+			"failed to get stat for targetpath %q: %v", targetPath, err)
+	}
+
+	if stat.Mode().IsDir() {
+		return csicommon.FilesystemNodeGetVolumeStats(ctx, ns.Mounter, targetPath)
+	}
+
+	return nil, status.Errorf(codes.InvalidArgument,
+		"targetpath %q is not a directory or device", targetPath)
+}
+
+// mountNFS mounts nfs volumes.
+func (ns *NodeServer) mountNFS(
+	ctx context.Context,
+	volumeID, source, mountPoint, netNamespaceFilePath string,
+	mountOptions []string,
+) error {
+	var (
+		stderr string
+		err    error
+	)
+
+	notMnt, err := ns.Mounter.IsLikelyNotMountPoint(mountPoint)
+	if err != nil {
+		if os.IsNotExist(err) {
+			err = os.MkdirAll(mountPoint, defaultMountPermission)
+			if err != nil {
+				return err
+			}
+			notMnt = true
+		} else {
+			return err
+		}
+	}
+	if !notMnt {
+		log.DebugLog(ctx, "nfs: volume is already mounted to %s", mountPoint)
+
+		return nil
+	}
+
+	args := []string{
+		"-t", "nfs",
+		source,
+		mountPoint,
+	}
+
+	if len(mountOptions) > 0 {
+		args = append(append(args, "-o"), mountOptions...)
+	}
+
+	log.DefaultLog("nfs: mounting volumeID(%v) source(%s) targetPath(%s) mountflags(%v)",
+		volumeID, source, mountPoint, mountOptions)
+	if netNamespaceFilePath != "" {
+		_, stderr, err = util.ExecuteCommandWithNSEnter(
+			ctx, netNamespaceFilePath, "mount", args[:]...)
+	} else {
+		err = ns.Mounter.Mount(source, mountPoint, "nfs", mountOptions)
+	}
+	if err != nil {
+		return fmt.Errorf("nfs: failed to mount %q to %q : %w stderr: %q",
+			source, mountPoint, err, stderr)
+	}
+	if stderr != "" {
+		return fmt.Errorf("nfs: failed to mount %q to %q : stderr %q",
+			source, mountPoint, stderr)
+	}
+
+	return err
+}
+
+// validateNodePublishVolumeRequest validates node publish volume request.
+func validateNodePublishVolumeRequest(req *csi.NodePublishVolumeRequest) error {
+	switch {
+	case req.GetVolumeId() == "":
+		return errors.New("volume ID missing in request")
+	case req.GetVolumeCapability() == nil:
+		return errors.New("volume capability missing in request")
+	case req.GetTargetPath() == "":
+		return errors.New("target path missing in request")
+	}
+
+	return nil
+}
+
+// getSource validates volume context, extracts and returns source.
+// This function expects `server` and `share` parameters to be set
+// and validates for the same.
+func getSource(volContext map[string]string) (string, error) {
+	server := volContext[paramServer]
+	if server == "" {
+		return "", fmt.Errorf("%v missing in request", paramServer)
+	}
+	baseDir := volContext[paramShare]
+	if baseDir == "" {
+		return "", fmt.Errorf("%v missing in request", paramShare)
+	}
+
+	if netutil.IsIPv6String(server) {
+		// if server is IPv6, format to [IPv6].
+		server = fmt.Sprintf("[%s]", server)
+	}
+
+	return fmt.Sprintf("%s:%s", server, baseDir), nil
+}

internal/nfs/nodeserver/nodeserver_test.go

@@ -0,0 +1,174 @@
+/*
+Copyright 2022 The Ceph-CSI Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package nodeserver
+
+import (
+	"testing"
+
+	"github.com/container-storage-interface/spec/lib/go/csi"
+)
+
+func Test_validateNodePublishVolumeRequest(t *testing.T) {
+	t.Parallel()
+	type args struct {
+		req *csi.NodePublishVolumeRequest
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{
+			name: "passing testcase",
+			args: args{
+				req: &csi.NodePublishVolumeRequest{
+					VolumeId:         "123",
+					TargetPath:       "/target",
+					VolumeCapability: &csi.VolumeCapability{},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name: "missing VolumeId",
+			args: args{
+				req: &csi.NodePublishVolumeRequest{
+					VolumeId:         "",
+					TargetPath:       "/target",
+					VolumeCapability: &csi.VolumeCapability{},
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "missing TargetPath",
+			args: args{
+				req: &csi.NodePublishVolumeRequest{
+					VolumeId:         "123",
+					TargetPath:       "",
+					VolumeCapability: &csi.VolumeCapability{},
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "missing VolumeCapability",
+			args: args{
+				req: &csi.NodePublishVolumeRequest{
+					VolumeId:         "123",
+					TargetPath:       "/target",
+					VolumeCapability: nil,
+				},
+			},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		currentTT := tt
+		t.Run(currentTT.name, func(t *testing.T) {
+			t.Parallel()
+			err := validateNodePublishVolumeRequest(currentTT.args.req)
+			if (err != nil) != currentTT.wantErr {
+				t.Errorf("validateNodePublishVoluemRequest() error = %v, wantErr %v", err, currentTT.wantErr)
+			}
+		})
+	}
+}
+
+func Test_getSource(t *testing.T) {
+	t.Parallel()
+	type args struct {
+		volContext map[string]string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    string
+		wantErr bool
+	}{
+		{
+			name: "hostname as address",
+			args: args{
+				volContext: map[string]string{
+					paramServer: "example.io",
+					paramShare:  "/a",
+				},
+			},
+			want:    "example.io:/a",
+			wantErr: false,
+		},
+		{
+			name: "ipv4 address",
+			args: args{
+				volContext: map[string]string{
+					paramServer: "10.12.1.0",
+					paramShare:  "/a",
+				},
+			},
+			want:    "10.12.1.0:/a",
+			wantErr: false,
+		},
+		{
+			name: "ipv6 address",
+			args: args{
+				volContext: map[string]string{
+					paramServer: "2001:0db8:3c4d:0015:0000:0000:1a2f:1a2b",
+					paramShare:  "/a",
+				},
+			},
+			want:    "[2001:0db8:3c4d:0015:0000:0000:1a2f:1a2b]:/a",
+			wantErr: false,
+		},
+		{
+			name: "missing server parameter",
+			args: args{
+				volContext: map[string]string{
+					paramServer: "",
+					paramShare:  "/a",
+				},
+			},
+			want:    "",
+			wantErr: true,
+		},
+		{
+			name: "missing share parameter",
+			args: args{
+				volContext: map[string]string{
+					paramServer: "10.12.1.0",
+					paramShare:  "",
+				},
+			},
+			want:    "",
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		currentTT := tt
+		t.Run(currentTT.name, func(t *testing.T) {
+			t.Parallel()
+			got, err := getSource(currentTT.args.volContext)
+			if (err != nil) != currentTT.wantErr {
+				t.Errorf("getSource() error = %v, wantErr %v", err, currentTT.wantErr)
+
+				return
+			}
+			if got != currentTT.want {
+				t.Errorf("getSource() = %v, want %v", got, currentTT.want)
+			}
+		})
+	}
+}

internal/util/csiconfig.go

@@ -59,6 +59,11 @@ type ClusterInfo struct {
 		// RadosNamespace is a rados namespace in the pool
 		RadosNamespace string `json:"radosNamespace"`
 	} `json:"rbd"`
+	// NFS contains NFS specific options
+	NFS struct {
+		// symlink filepath for the network namespace where we need to execute commands.
+		NetNamespaceFilePath string `json:"netNamespaceFilePath"`
+	} `json:"nfs"`
 }
 
 // Expected JSON structure in the passed in config file is,
@@ -194,3 +199,13 @@ func GetCephFSNetNamespaceFilePath(pathToConfig, clusterID string) (string, erro
 
 	return cluster.CephFS.NetNamespaceFilePath, nil
 }
+
+// GetNFSNetNamespaceFilePath returns the netNamespaceFilePath for NFS volumes.
+func GetNFSNetNamespaceFilePath(pathToConfig, clusterID string) (string, error) {
+	cluster, err := readClusterInfo(pathToConfig, clusterID)
+	if err != nil {
+		return "", err
+	}
+
+	return cluster.NFS.NetNamespaceFilePath, nil
+}

internal/util/csiconfig_test.go

@@ -291,3 +291,77 @@ func TestGetCephFSNetNamespaceFilePath(t *testing.T) {
 		})
 	}
 }
+
+func TestGetNFSNetNamespaceFilePath(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name      string
+		clusterID string
+		want      string
+	}{
+		{
+			name:      "get NFS specific NetNamespaceFilePath for cluster-1",
+			clusterID: "cluster-1",
+			want:      "/var/lib/kubelet/plugins/nfs.ceph.csi.com/cluster1-net",
+		},
+		{
+			name:      "get NFS specific NetNamespaceFilePath for cluster-2",
+			clusterID: "cluster-2",
+			want:      "/var/lib/kubelet/plugins/nfs.ceph.csi.com/cluster2-net",
+		},
+		{
+			name:      "when NFS specific NetNamespaceFilePath is empty",
+			clusterID: "cluster-3",
+			want:      "",
+		},
+	}
+
+	csiConfig := []ClusterInfo{
+		{
+			ClusterID: "cluster-1",
+			Monitors:  []string{"ip-1", "ip-2"},
+			NFS: struct {
+				NetNamespaceFilePath string `json:"netNamespaceFilePath"`
+			}{
+				NetNamespaceFilePath: "/var/lib/kubelet/plugins/nfs.ceph.csi.com/cluster1-net",
+			},
+		},
+		{
+			ClusterID: "cluster-2",
+			Monitors:  []string{"ip-3", "ip-4"},
+			NFS: struct {
+				NetNamespaceFilePath string `json:"netNamespaceFilePath"`
+			}{
+				NetNamespaceFilePath: "/var/lib/kubelet/plugins/nfs.ceph.csi.com/cluster2-net",
+			},
+		},
+		{
+			ClusterID: "cluster-3",
+			Monitors:  []string{"ip-5", "ip-6"},
+		},
+	}
+	csiConfigFileContent, err := json.Marshal(csiConfig)
+	if err != nil {
+		t.Errorf("failed to marshal csi config info %v", err)
+	}
+	tmpConfPath := t.TempDir() + "/ceph-csi.json"
+	err = os.WriteFile(tmpConfPath, csiConfigFileContent, 0o600)
+	if err != nil {
+		t.Errorf("failed to write %s file content: %v", CsiConfigFile, err)
+	}
+	for _, tt := range tests {
+		ts := tt
+		t.Run(ts.name, func(t *testing.T) {
+			t.Parallel()
+			got, err := GetNFSNetNamespaceFilePath(tmpConfPath, ts.clusterID)
+			if err != nil {
+				t.Errorf("GetNFSNetNamespaceFilePath() error = %v", err)
+
+				return
+			}
+			if got != ts.want {
+				t.Errorf("GetNFSNetNamespaceFilePath() = %v, want %v", got, ts.want)
+			}
+		})
+	}
+}