// IsLikelyNotMountPoint determines whether a path is a mountpoint by calling findmnt
// in the host's root mount namespace.
func (n *NsenterMounter) IsLikelyNotMountPoint(file string) (bool, error) {
file, err := filepath.Abs(file)
if err != nil {
return true, err
}
args := []string{"--mount=/rootfs/proc/1/ns/mnt", "--", n.absHostPath("findmnt"), "-o", "target", "--noheadings", "--target", file}
glog.V(5).Infof("findmnt command: %v %v", nsenterPath, args)
exec := exec.New()
out, err := exec.Command(nsenterPath, args...).CombinedOutput()
if err != nil {
glog.Errorf("Failed to nsenter mount, return file doesn't exist: %v", err)
// If the command itself is correct, then if we encountered error
// then most likely this means that the directory does not exist.
return true, os.ErrNotExist
}
strOut := strings.TrimSuffix(string(out), "\n")
glog.V(5).Infof("IsLikelyNotMountPoint findmnt output: %v", strOut)
if strOut == file {
return false, nil
}
return true, nil
}
// doNsenterMount nsenters the host's mount namespace and performs the
// requested mount.
func (n *NsenterMounter) doNsenterMount(source, target, fstype string, options []string) error {
glog.V(5).Infof("nsenter Mounting %s %s %s %v", source, target, fstype, options)
args := n.makeNsenterArgs(source, target, fstype, options)
glog.V(5).Infof("Mount command: %v %v", nsenterPath, args)
exec := exec.New()
outputBytes, err := exec.Command(nsenterPath, args...).CombinedOutput()
if len(outputBytes) != 0 {
glog.V(5).Infof("Output from mount command: %v", string(outputBytes))
}
return err
}
// Unmount runs umount(8) in the host's mount namespace.
func (n *NsenterMounter) Unmount(target string) error {
args := []string{
"--mount=/rootfs/proc/1/ns/mnt",
"--",
n.absHostPath("umount"),
target,
}
glog.V(5).Infof("Unmount command: %v %v", nsenterPath, args)
exec := exec.New()
outputBytes, err := exec.Command(nsenterPath, args...).CombinedOutput()
if len(outputBytes) != 0 {
glog.V(5).Infof("Output from mount command: %v", string(outputBytes))
}
return err
}