ceph-csi/pkg/rbd/nodeserver.go
Madhu Rajanna 25642fe404 Add method comments
Signed-off-by: Madhu Rajanna <mrajanna@redhat.com>
2019-01-29 11:20:35 +05:30

249 lines
8.1 KiB
Go

/*
Copyright 2018 The Kubernetes 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 rbd
import (
"fmt"
"os"
"os/exec"
"regexp"
"strings"
"github.com/golang/glog"
"golang.org/x/net/context"
"github.com/container-storage-interface/spec/lib/go/csi"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
"k8s.io/kubernetes/pkg/util/mount"
"github.com/kubernetes-csi/drivers/pkg/csi-common"
)
// NodeServer struct of ceph rbd driver with supported methods of CSI
// node server spec
type NodeServer struct {
*csicommon.DefaultNodeServer
mounter mount.Interface
}
//TODO remove both stage and unstage methods
//once https://github.com/kubernetes-csi/drivers/pull/145 is merged
// NodeStageVolume returns unimplemented response
func (ns *NodeServer) NodeStageVolume(ctx context.Context, req *csi.NodeStageVolumeRequest) (*csi.NodeStageVolumeResponse, error) {
return nil, status.Error(codes.Unimplemented, "")
}
// NodeUnstageVolume returns unimplemented response
func (ns *NodeServer) NodeUnstageVolume(ctx context.Context, req *csi.NodeUnstageVolumeRequest) (*csi.NodeUnstageVolumeResponse, error) {
return nil, status.Error(codes.Unimplemented, "")
}
// NodePublishVolume mounts the volume mounted to the device path to the target
// path
func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error) {
targetPath := req.GetTargetPath()
targetPathMutex.LockKey(targetPath)
defer targetPathMutex.UnlockKey(targetPath)
var volName string
isBlock := req.GetVolumeCapability().GetBlock() != nil
if isBlock {
// Get volName from targetPath
s := strings.Split(targetPath, "/")
volName = s[len(s)-1]
} else {
// Get volName from targetPath
if !strings.HasSuffix(targetPath, "/mount") {
return nil, fmt.Errorf("rbd: malformed the value of target path: %s", targetPath)
}
s := strings.Split(strings.TrimSuffix(targetPath, "/mount"), "/")
volName = s[len(s)-1]
}
// Check if that target path exists properly
notMnt, err := ns.mounter.IsNotMountPoint(targetPath)
if err != nil {
if os.IsNotExist(err) {
if isBlock {
// create an empty file
targetPathFile, err := os.OpenFile(targetPath, os.O_CREATE|os.O_RDWR, 0750)
if err != nil {
glog.V(4).Infof("Failed to create targetPath:%s with error: %v", targetPath, err)
return nil, status.Error(codes.Internal, err.Error())
}
if err := targetPathFile.Close(); err != nil {
glog.V(4).Infof("Failed to close targetPath:%s with error: %v", targetPath, err)
return nil, status.Error(codes.Internal, err.Error())
}
} else {
// Create a directory
if err = os.MkdirAll(targetPath, 0750); err != nil {
return nil, status.Error(codes.Internal, err.Error())
}
}
notMnt = true
} else {
return nil, status.Error(codes.Internal, err.Error())
}
}
if !notMnt {
return &csi.NodePublishVolumeResponse{}, nil
}
volOptions, err := getRBDVolumeOptions(req.GetVolumeContext())
if err != nil {
return nil, err
}
volOptions.VolName = volName
// Mapping RBD image
devicePath, err := attachRBDImage(volOptions, volOptions.UserID, req.GetSecrets())
if err != nil {
return nil, err
}
glog.V(4).Infof("rbd image: %s/%s was successfully mapped at %s\n", req.GetVolumeId(), volOptions.Pool, devicePath)
// Publish Path
fsType := req.GetVolumeCapability().GetMount().GetFsType()
readOnly := req.GetReadonly()
attrib := req.GetVolumeContext()
mountFlags := req.GetVolumeCapability().GetMount().GetMountFlags()
glog.V(4).Infof("target %v\nisBlock %v\nfstype %v\ndevice %v\nreadonly %v\nattributes %v\n mountflags %v\n",
targetPath, isBlock, fsType, devicePath, readOnly, attrib, mountFlags)
diskMounter := &mount.SafeFormatAndMount{Interface: ns.mounter, Exec: mount.NewOsExec()}
if isBlock {
options := []string{"bind"}
if err := diskMounter.Mount(devicePath, targetPath, fsType, options); err != nil {
return nil, err
}
} else {
options := []string{}
if readOnly {
options = append(options, "ro")
}
if err := diskMounter.FormatAndMount(devicePath, targetPath, fsType, options); err != nil {
return nil, err
}
}
return &csi.NodePublishVolumeResponse{}, nil
}
// NodeUnpublishVolume unmounts the volume from the target path
func (ns *NodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpublishVolumeRequest) (*csi.NodeUnpublishVolumeResponse, error) {
targetPath := req.GetTargetPath()
targetPathMutex.LockKey(targetPath)
defer targetPathMutex.UnlockKey(targetPath)
notMnt, err := ns.mounter.IsNotMountPoint(targetPath)
if err != nil {
if os.IsNotExist(err) {
// targetPath has already been deleted
glog.V(4).Infof("targetPath: %s has already been deleted", targetPath)
return &csi.NodeUnpublishVolumeResponse{}, nil
}
return nil, status.Error(codes.NotFound, err.Error())
}
if notMnt {
// TODO should consider deleting path instead of returning error,
// once all codes become ready for csi 1.0.
return nil, status.Error(codes.NotFound, "Volume not mounted")
}
devicePath, cnt, err := mount.GetDeviceNameFromMount(ns.mounter, targetPath)
if err != nil {
return nil, status.Error(codes.Internal, err.Error())
}
// Bind mounted device needs to be resolved by using resolveBindMountedBlockDevice
if devicePath == "devtmpfs" {
var err error
devicePath, err = resolveBindMountedBlockDevice(targetPath)
if err != nil {
return nil, status.Error(codes.Internal, err.Error())
}
glog.V(4).Infof("NodeUnpublishVolume: devicePath: %s, (original)cnt: %d\n", devicePath, cnt)
// cnt for GetDeviceNameFromMount is broken for bind mouted device,
// it counts total number of mounted "devtmpfs", instead of counting this device.
// So, forcibly setting cnt to 1 here.
// TODO : fix this properly
cnt = 1
}
glog.V(4).Infof("NodeUnpublishVolume: targetPath: %s, devicePath: %s\n", targetPath, devicePath)
// Unmounting the image
err = ns.mounter.Unmount(targetPath)
if err != nil {
glog.V(3).Infof("failed to unmount targetPath: %s with error: %v", targetPath, err)
return nil, status.Error(codes.Internal, err.Error())
}
cnt--
if cnt != 0 {
// TODO should this be fixed not to success, so that driver can retry unmounting?
return &csi.NodeUnpublishVolumeResponse{}, nil
}
// Unmapping rbd device
if err := detachRBDDevice(devicePath); err != nil {
glog.V(3).Infof("failed to unmap rbd device: %s with error: %v", devicePath, err)
return nil, err
}
// Remove targetPath
if err := os.RemoveAll(targetPath); err != nil {
glog.V(3).Infof("failed to remove targetPath: %s with error: %v", targetPath, err)
return nil, err
}
return &csi.NodeUnpublishVolumeResponse{}, nil
}
func resolveBindMountedBlockDevice(mountPath string) (string, error) {
cmd := exec.Command("findmnt", "-n", "-o", "SOURCE", "--first-only", "--target", mountPath)
out, err := cmd.CombinedOutput()
if err != nil {
glog.V(2).Infof("Failed findmnt command for path %s: %s %v", mountPath, out, err)
return "", err
}
return parseFindMntResolveSource(string(out))
}
// parse output of "findmnt -o SOURCE --first-only --target" and return just the SOURCE
func parseFindMntResolveSource(out string) (string, error) {
// cut trailing newline
out = strings.TrimSuffix(out, "\n")
// Check if out is a mounted device
reMnt := regexp.MustCompile("^(/[^/]+(?:/[^/]*)*)$")
if match := reMnt.FindStringSubmatch(out); match != nil {
return match[1], nil
}
// Check if out is a block device
reBlk := regexp.MustCompile("^devtmpfs\\[(/[^/]+(?:/[^/]*)*)\\]$")
if match := reBlk.FindStringSubmatch(out); match != nil {
return fmt.Sprintf("/dev%s", match[1]), nil
}
return "", fmt.Errorf("parseFindMntResolveSource: %s doesn't match to any expected findMnt output", out)
}