cephfs: enable VolumeCondition with new health-checker

The HealthChecker is configured to use the Staging path pf the volume,
with a `.csi/` subdirectory. In the future this directory could be a
directory that is not under the Published directory.

Fixes: #4219
Signed-off-by: Niels de Vos <ndevos@ibm.com>

internal/cephfs/driver.go

@@ -25,6 +25,7 @@ import (
 	casceph "github.com/ceph/ceph-csi/internal/csi-addons/cephfs"
 	csiaddons "github.com/ceph/ceph-csi/internal/csi-addons/server"
 	csicommon "github.com/ceph/ceph-csi/internal/csi-common"
+	hc "github.com/ceph/ceph-csi/internal/health-checker"
 	"github.com/ceph/ceph-csi/internal/journal"
 	"github.com/ceph/ceph-csi/internal/util"
 	"github.com/ceph/ceph-csi/internal/util/log"
@@ -82,6 +83,7 @@ func NewNodeServer(
 		VolumeLocks:        util.NewVolumeLocks(),
 		kernelMountOptions: kernelMountOptions,
 		fuseMountOptions:   fuseMountOptions,
+		healthChecker:      hc.NewHealthCheckManager(),
 	}
 }
 

internal/cephfs/nodeserver.go

@@ -29,6 +29,7 @@ import (
 	"github.com/ceph/ceph-csi/internal/cephfs/store"
 	fsutil "github.com/ceph/ceph-csi/internal/cephfs/util"
 	csicommon "github.com/ceph/ceph-csi/internal/csi-common"
+	hc "github.com/ceph/ceph-csi/internal/health-checker"
 	"github.com/ceph/ceph-csi/internal/util"
 	"github.com/ceph/ceph-csi/internal/util/fscrypt"
 	"github.com/ceph/ceph-csi/internal/util/log"
@@ -47,6 +48,7 @@ type NodeServer struct {
 	VolumeLocks        *util.VolumeLocks
 	kernelMountOptions string
 	fuseMountOptions   string
+	healthChecker      hc.Manager
 }
 
 func getCredentialsForVolume(
@@ -228,6 +230,8 @@ func (ns *NodeServer) NodeStageVolume(
 			return nil, status.Error(codes.Internal, err.Error())
 		}
 
+		ns.startSharedHealthChecker(ctx, req.GetVolumeId(), stagingTargetPath)
+
 		return &csi.NodeStageVolumeResponse{}, nil
 	}
 
@@ -270,9 +274,24 @@ func (ns *NodeServer) NodeStageVolume(
 		}
 	}
 
+	ns.startSharedHealthChecker(ctx, req.GetVolumeId(), stagingTargetPath)
+
 	return &csi.NodeStageVolumeResponse{}, nil
 }
 
+// startSharedHealthChecker starts a health-checker on the stagingTargetPath.
+// This checker can be shared between multiple containers.
+//
+// TODO: start a FileChecker for read-writable volumes that have an app-data subdir.
+func (ns *NodeServer) startSharedHealthChecker(ctx context.Context, volumeID, dir string) {
+	// The StatChecker works for volumes that do not have a dedicated app-data
+	// subdirectory, or are read-only.
+	err := ns.healthChecker.StartSharedChecker(volumeID, dir, hc.StatCheckerType)
+	if err != nil {
+		log.WarningLog(ctx, "failed to start healthchecker: %v", err)
+	}
+}
+
 func (ns *NodeServer) mount(
 	ctx context.Context,
 	mnt mounter.VolumeMounter,
@@ -479,7 +498,8 @@ func (ns *NodeServer) NodePublishVolume(
 
 	// Ensure staging target path is a mountpoint.
 
-	if isMnt, err := util.IsMountPoint(ns.Mounter, stagingTargetPath); err != nil {
+	isMnt, err := util.IsMountPoint(ns.Mounter, stagingTargetPath)
+	if err != nil {
 		log.ErrorLog(ctx, "stat failed: %v", err)
 
 		return nil, status.Error(codes.Internal, err.Error())
@@ -491,7 +511,7 @@ func (ns *NodeServer) NodePublishVolume(
 
 	// Check if the volume is already mounted
 
-	isMnt, err := util.IsMountPoint(ns.Mounter, targetPath)
+	isMnt, err = util.IsMountPoint(ns.Mounter, targetPath)
 	if err != nil {
 		log.ErrorLog(ctx, "stat failed: %v", err)
 
@@ -545,6 +565,10 @@ func (ns *NodeServer) NodeUnpublishVolume(
 	// considering kubelet make sure node operations like unpublish/unstage...etc can not be called
 	// at same time, an explicit locking at time of nodeunpublish is not required.
 	targetPath := req.GetTargetPath()
+
+	// stop the health-checker that may have been started in NodeGetVolumeStats()
+	ns.healthChecker.StopChecker(req.GetVolumeId(), targetPath)
+
 	isMnt, err := util.IsMountPoint(ns.Mounter, targetPath)
 	if err != nil {
 		log.ErrorLog(ctx, "stat failed: %v", err)
@@ -599,6 +623,9 @@ func (ns *NodeServer) NodeUnstageVolume(
 	}
 
 	volID := req.GetVolumeId()
+
+	ns.healthChecker.StopSharedChecker(volID)
+
 	if acquired := ns.VolumeLocks.TryAcquire(volID); !acquired {
 		log.ErrorLog(ctx, util.VolumeOperationAlreadyExistsFmt, volID)
 
@@ -670,6 +697,13 @@ func (ns *NodeServer) NodeGetCapabilities(
 					},
 				},
 			},
+			{
+				Type: &csi.NodeServiceCapability_Rpc{
+					Rpc: &csi.NodeServiceCapability_RPC{
+						Type: csi.NodeServiceCapability_RPC_VOLUME_CONDITION,
+					},
+				},
+			},
 			{
 				Type: &csi.NodeServiceCapability_Rpc{
 					Rpc: &csi.NodeServiceCapability_RPC{
@@ -694,6 +728,35 @@ func (ns *NodeServer) NodeGetVolumeStats(
 		return nil, status.Error(codes.InvalidArgument, err.Error())
 	}
 
+	// health check first, return without stats if unhealthy
+	healthy, msg := ns.healthChecker.IsHealthy(req.GetVolumeId(), targetPath)
+
+	// If healthy and an error is returned, it means that the checker was not
+	// started. This could happen when the node-plugin was restarted and the
+	// volume is already staged and published.
+	if healthy && msg != nil {
+		// Start a StatChecker for the mounted targetPath, this prevents
+		// writing a file in the user-visible location. Ideally a (shared)
+		// FileChecker is started with the stagingTargetPath, but we can't
+		// get the stagingPath from the request easily.
+		// TODO: resolve the stagingPath like rbd.getStagingPath() does
+		err = ns.healthChecker.StartChecker(req.GetVolumeId(), targetPath, hc.StatCheckerType)
+		if err != nil {
+			log.WarningLog(ctx, "failed to start healthchecker: %v", err)
+		}
+	}
+
+	// !healthy indicates a problem with the volume
+	if !healthy {
+		return &csi.NodeGetVolumeStatsResponse{
+			VolumeCondition: &csi.VolumeCondition{
+				Abnormal: true,
+				Message:  msg.Error(),
+			},
+		}, nil
+	}
+
+	// warning: stat() may hang on an unhealthy volume
 	stat, err := os.Stat(targetPath)
 	if err != nil {
 		if util.IsCorruptedMountError(err) {