Documentation

Overview

Package mount defines an interface to mounting filesystems.

TODO(thockin): This whole pkg is pretty linux-centric. As soon as we have an alternate platform, we will need to abstract further.

Index

Constants

View Source
const FakeActionMount = "mount"

Values for FakeAction.Action

View Source
const FakeActionUnmount = "unmount"

Variables

This section is empty.

Functions

func CleanupMountPoint

func CleanupMountPoint(mountPath string, mounter Interface, extensiveMountPointCheck bool) error

CleanupMountPoint unmounts the given path and deletes the remaining directory if successful. if extensiveMountPointCheck is true IsNotMountPoint will be called instead of IsLikelyNotMountPoint. IsNotMountPoint is more expensive but properly handles bind mounts within the same fs.

func GetDeviceNameFromMount

func GetDeviceNameFromMount(mounter Interface, mountPath string) (string, int, error)

GetDeviceNameFromMount: given a mnt point, find the device from /proc/mounts returns the device name, reference count, and error code

func HasMountRefs

func HasMountRefs(mountPath string, mountRefs []string) bool

func IsCorruptedMnt

func IsCorruptedMnt(err error) bool

IsCorruptedMnt return true if err is about corrupted mount point

func PathExists

func PathExists(path string) (bool, error)

TODO: clean this up to use pkg/util/file/FileExists PathExists returns true if the specified path exists.

func PathWithinBase

func PathWithinBase(fullPath, basePath string) bool

PathWithinBase checks if give path is within given base directory.

func StartsWithBackstep

func StartsWithBackstep(rel string) bool

StartsWithBackstep checks if the given path starts with a backstep segment

Types

type Exec

type Exec interface {
	// Run executes a command and returns its stdout + stderr combined in one
	// stream.
	Run(cmd string, args ...string) ([]byte, error)
}

Exec executes command where mount utilities are. This can be either the host, container where kubelet runs or even a remote pod with mount utilities. Usual k8s.io/utils/exec interface is not used because kubelet.RunInContainer does not provide stdin/stdout/stderr streams.

func NewOsExec

func NewOsExec() Exec

type FakeAction

type FakeAction struct {
	Action string // "mount" or "unmount"
	Target string // applies to both mount and unmount actions
	Source string // applies only to "mount" actions
	FSType string // applies only to "mount" actions
}

FakeAction objects are logged every time a fake mount or unmount is called.

type FakeExec

type FakeExec struct {
	// contains filtered or unexported fields
}

Fake for testing.

func NewFakeExec

func NewFakeExec(run runHook) *FakeExec

func (*FakeExec) Run

func (f *FakeExec) Run(cmd string, args ...string) ([]byte, error)

type FakeMounter

type FakeMounter struct {
	MountPoints []MountPoint
	Log         []FakeAction
	Filesystem  map[string]FileType
	// Error to return for a path when calling IsLikelyNotMountPoint
	MountCheckErrors map[string]error
	// contains filtered or unexported fields
}

FakeMounter implements mount.Interface for tests.

func (*FakeMounter) DeviceOpened

func (f *FakeMounter) DeviceOpened(pathname string) (bool, error)
func (f *FakeMounter) EvalHostSymlinks(pathname string) (string, error)

func (*FakeMounter) ExistsPath

func (f *FakeMounter) ExistsPath(pathname string) (bool, error)

func (*FakeMounter) GetDeviceNameFromMount

func (f *FakeMounter) GetDeviceNameFromMount(mountPath, pluginDir string) (string, error)

func (*FakeMounter) GetFSGroup

func (f *FakeMounter) GetFSGroup(pathname string) (int64, error)

func (*FakeMounter) GetFileType

func (f *FakeMounter) GetFileType(pathname string) (FileType, error)

func (*FakeMounter) GetMode

func (f *FakeMounter) GetMode(pathname string) (os.FileMode, error)

func (*FakeMounter) GetMountRefs

func (f *FakeMounter) GetMountRefs(pathname string) ([]string, error)

func (*FakeMounter) GetSELinuxSupport

func (f *FakeMounter) GetSELinuxSupport(pathname string) (bool, error)

func (*FakeMounter) IsLikelyNotMountPoint

func (f *FakeMounter) IsLikelyNotMountPoint(file string) (bool, error)

func (*FakeMounter) IsMountPointMatch

func (f *FakeMounter) IsMountPointMatch(mp MountPoint, dir string) bool

func (*FakeMounter) IsNotMountPoint

func (f *FakeMounter) IsNotMountPoint(dir string) (bool, error)

func (*FakeMounter) List

func (f *FakeMounter) List() ([]MountPoint, error)

func (*FakeMounter) MakeDir

func (f *FakeMounter) MakeDir(pathname string) error

func (*FakeMounter) MakeFile

func (f *FakeMounter) MakeFile(pathname string) error

func (*FakeMounter) MakeRShared

func (f *FakeMounter) MakeRShared(path string) error

func (*FakeMounter) Mount

func (f *FakeMounter) Mount(source string, target string, fstype string, options []string) error

func (*FakeMounter) PathIsDevice

func (f *FakeMounter) PathIsDevice(pathname string) (bool, error)

func (*FakeMounter) ResetLog

func (f *FakeMounter) ResetLog()

func (*FakeMounter) Unmount

func (f *FakeMounter) Unmount(target string) error

type FileType

type FileType string
const (
	MountsInGlobalPDPath          = "mounts"
	FileTypeDirectory    FileType = "Directory"
	FileTypeFile         FileType = "File"
	FileTypeSocket       FileType = "Socket"
	FileTypeCharDev      FileType = "CharDevice"
	FileTypeBlockDev     FileType = "BlockDevice"
)

type Interface

type Interface interface {
	// Mount mounts source to target as fstype with given options.
	Mount(source string, target string, fstype string, options []string) error
	// Unmount unmounts given target.
	Unmount(target string) error
	// List returns a list of all mounted filesystems.  This can be large.
	// On some platforms, reading mounts is not guaranteed consistent (i.e.
	// it could change between chunked reads). This is guaranteed to be
	// consistent.
	List() ([]MountPoint, error)
	// IsMountPointMatch determines if the mountpoint matches the dir
	IsMountPointMatch(mp MountPoint, dir string) bool
	// IsNotMountPoint determines if a directory is a mountpoint.
	// It should return ErrNotExist when the directory does not exist.
	// IsNotMountPoint is more expensive than IsLikelyNotMountPoint.
	// IsNotMountPoint detects bind mounts in linux.
	// IsNotMountPoint enumerates all the mountpoints using List() and
	// the list of mountpoints may be large, then it uses
	// IsMountPointMatch to evaluate whether the directory is a mountpoint
	IsNotMountPoint(file string) (bool, error)
	// IsLikelyNotMountPoint uses heuristics to determine if a directory
	// is a mountpoint.
	// It should return ErrNotExist when the directory does not exist.
	// IsLikelyNotMountPoint does NOT properly detect all mountpoint types
	// most notably linux bind mounts.
	IsLikelyNotMountPoint(file string) (bool, error)
	// DeviceOpened determines if the device is in use elsewhere
	// on the system, i.e. still mounted.
	DeviceOpened(pathname string) (bool, error)
	// PathIsDevice determines if a path is a device.
	PathIsDevice(pathname string) (bool, error)
	// GetDeviceNameFromMount finds the device name by checking the mount path
	// to get the global mount path which matches its plugin directory
	GetDeviceNameFromMount(mountPath, pluginDir string) (string, error)
	// MakeRShared checks that given path is on a mount with 'rshared' mount
	// propagation. If not, it bind-mounts the path as rshared.
	MakeRShared(path string) error
	// GetFileType checks for file/directory/socket/block/character devices.
	// Will operate in the host mount namespace if kubelet is running in a container
	GetFileType(pathname string) (FileType, error)
	// MakeFile creates an empty file.
	// Will operate in the host mount namespace if kubelet is running in a container
	MakeFile(pathname string) error
	// MakeDir creates a new directory.
	// Will operate in the host mount namespace if kubelet is running in a container
	MakeDir(pathname string) error
	// Will operate in the host mount namespace if kubelet is running in a container.
	// Error is returned on any other error than "file not found".
	ExistsPath(pathname string) (bool, error)
	// EvalHostSymlinks returns the path name after evaluating symlinks.
	// Will operate in the host mount namespace if kubelet is running in a container.
	EvalHostSymlinks(pathname string) (string, error)
	// GetMountRefs finds all mount references to the path, returns a
	// list of paths. Path could be a mountpoint path, device or a normal
	// directory (for bind mount).
	GetMountRefs(pathname string) ([]string, error)
	// GetFSGroup returns FSGroup of the path.
	GetFSGroup(pathname string) (int64, error)
	// GetSELinuxSupport returns true if given path is on a mount that supports
	// SELinux.
	GetSELinuxSupport(pathname string) (bool, error)
	// GetMode returns permissions of the path.
	GetMode(pathname string) (os.FileMode, error)
}

func New

func New(mounterPath string) Interface

New returns a mount.Interface for the current system. It provides options to override the default mounter behavior. mounterPath allows using an alternative to `/bin/mount` for mounting.

func NewExecMounter

func NewExecMounter(exec Exec, wrapped Interface) Interface

type MountPoint

type MountPoint struct {
	Device string
	Path   string
	Type   string
	Opts   []string
	Freq   int
	Pass   int
}

This represents a single line in /proc/mounts or /etc/fstab.

type Mounter

type Mounter struct {
	// contains filtered or unexported fields
}

Mounter provides the default implementation of mount.Interface for the linux platform. This implementation assumes that the kubelet is running in the host's root mount namespace.

func (*Mounter) DeviceOpened

func (mounter *Mounter) DeviceOpened(pathname string) (bool, error)

DeviceOpened checks if block device in use by calling Open with O_EXCL flag. If pathname is not a device, log and return false with nil error. If open returns errno EBUSY, return true with nil error. If open returns nil, return false with nil error. Otherwise, return false with error

func (mounter *Mounter) EvalHostSymlinks(pathname string) (string, error)

func (*Mounter) ExistsPath

func (mounter *Mounter) ExistsPath(pathname string) (bool, error)

func (*Mounter) GetDeviceNameFromMount

func (mounter *Mounter) GetDeviceNameFromMount(mountPath, pluginDir string) (string, error)

GetDeviceNameFromMount: given a mount point, find the device name from its global mount point

func (*Mounter) GetFSGroup

func (mounter *Mounter) GetFSGroup(pathname string) (int64, error)

func (*Mounter) GetFileType

func (mounter *Mounter) GetFileType(pathname string) (FileType, error)

func (*Mounter) GetMode

func (mounter *Mounter) GetMode(pathname string) (os.FileMode, error)

func (*Mounter) GetMountRefs

func (mounter *Mounter) GetMountRefs(pathname string) ([]string, error)

func (*Mounter) GetSELinuxSupport

func (mounter *Mounter) GetSELinuxSupport(pathname string) (bool, error)

func (*Mounter) IsLikelyNotMountPoint

func (mounter *Mounter) IsLikelyNotMountPoint(file string) (bool, error)

IsLikelyNotMountPoint determines if a directory is not a mountpoint. It is fast but not necessarily ALWAYS correct. If the path is in fact a bind mount from one part of a mount to another it will not be detected. mkdir /tmp/a /tmp/b; mount --bin /tmp/a /tmp/b; IsLikelyNotMountPoint("/tmp/b") will return true. When in fact /tmp/b is a mount point. If this situation if of interest to you, don't use this function...

func (*Mounter) IsMountPointMatch

func (mounter *Mounter) IsMountPointMatch(mp MountPoint, dir string) bool

func (*Mounter) IsNotMountPoint

func (mounter *Mounter) IsNotMountPoint(dir string) (bool, error)

func (*Mounter) List

func (*Mounter) List() ([]MountPoint, error)

List returns a list of all mounted filesystems.

func (*Mounter) MakeDir

func (mounter *Mounter) MakeDir(pathname string) error

func (*Mounter) MakeFile

func (mounter *Mounter) MakeFile(pathname string) error

func (*Mounter) MakeRShared

func (mounter *Mounter) MakeRShared(path string) error

func (*Mounter) Mount

func (mounter *Mounter) Mount(source string, target string, fstype string, options []string) error

Mount mounts source to target as fstype with given options. 'source' and 'fstype' must be an empty string in case it's not required, e.g. for remount, or for auto filesystem type, where kernel handles fstype for you. The mount 'options' is a list of options, currently come from mount(8), e.g. "ro", "remount", "bind", etc. If no more option is required, call Mount with an empty string list or nil.

func (*Mounter) PathIsDevice

func (mounter *Mounter) PathIsDevice(pathname string) (bool, error)

PathIsDevice uses FileInfo returned from os.Stat to check if path refers to a device.

func (*Mounter) Unmount

func (mounter *Mounter) Unmount(target string) error

Unmount unmounts the target.

type NsenterMounter

type NsenterMounter struct {
	// contains filtered or unexported fields
}

Currently, all docker containers receive their own mount namespaces. NsenterMounter works by executing nsenter to run commands in the host's mount namespace.

func NewNsenterMounter

func NewNsenterMounter(rootDir string, ne *nsenter.Nsenter) *NsenterMounter

NewNsenterMounter creates a new mounter for kubelet that runs as a container.

func (*NsenterMounter) DeviceOpened

func (n *NsenterMounter) DeviceOpened(pathname string) (bool, error)

DeviceOpened checks if block device in use by calling Open with O_EXCL flag. Returns true if open returns errno EBUSY, and false if errno is nil. Returns an error if errno is any error other than EBUSY. Returns with error if pathname is not a device.

func (mounter *NsenterMounter) EvalHostSymlinks(pathname string) (string, error)

func (*NsenterMounter) ExistsPath

func (mounter *NsenterMounter) ExistsPath(pathname string) (bool, error)

func (*NsenterMounter) GetDeviceNameFromMount

func (n *NsenterMounter) GetDeviceNameFromMount(mountPath, pluginDir string) (string, error)

GetDeviceNameFromMount given a mount point, find the volume id from checking /proc/mounts

func (*NsenterMounter) GetFSGroup

func (mounter *NsenterMounter) GetFSGroup(pathname string) (int64, error)

func (*NsenterMounter) GetFileType

func (mounter *NsenterMounter) GetFileType(pathname string) (FileType, error)

func (*NsenterMounter) GetMode

func (mounter *NsenterMounter) GetMode(pathname string) (os.FileMode, error)

func (*NsenterMounter) GetMountRefs

func (mounter *NsenterMounter) GetMountRefs(pathname string) ([]string, error)

func (*NsenterMounter) GetSELinuxSupport

func (mounter *NsenterMounter) GetSELinuxSupport(pathname string) (bool, error)

func (*NsenterMounter) IsLikelyNotMountPoint

func (n *NsenterMounter) IsLikelyNotMountPoint(file string) (bool, error)

IsLikelyNotMountPoint determines whether a path is a mountpoint by calling findmnt in the host's root mount namespace.

func (*NsenterMounter) IsMountPointMatch

func (*NsenterMounter) IsMountPointMatch(mp MountPoint, dir string) bool

func (*NsenterMounter) IsNotMountPoint

func (m *NsenterMounter) IsNotMountPoint(dir string) (bool, error)

func (*NsenterMounter) List

func (*NsenterMounter) List() ([]MountPoint, error)

List returns a list of all mounted filesystems in the host's mount namespace.

func (*NsenterMounter) MakeDir

func (mounter *NsenterMounter) MakeDir(pathname string) error

func (*NsenterMounter) MakeFile

func (mounter *NsenterMounter) MakeFile(pathname string) error

func (*NsenterMounter) MakeRShared

func (n *NsenterMounter) MakeRShared(path string) error

func (*NsenterMounter) Mount

func (n *NsenterMounter) Mount(source string, target string, fstype string, options []string) error

Mount runs mount(8) in the host's root mount namespace. Aside from this aspect, Mount has the same semantics as the mounter returned by mount.New()

func (*NsenterMounter) PathIsDevice

func (n *NsenterMounter) PathIsDevice(pathname string) (bool, error)

PathIsDevice uses FileInfo returned from os.Stat to check if path refers to a device.

func (*NsenterMounter) Unmount

func (n *NsenterMounter) Unmount(target string) error

Unmount runs umount(8) in the host's mount namespace.

type SafeFormatAndMount

type SafeFormatAndMount struct {
	Interface
	Exec
}

SafeFormatAndMount probes a device to see if it is formatted. Namely it checks to see if a file system is present. If so it mounts it otherwise the device is formatted first then mounted.

func (*SafeFormatAndMount) FormatAndMount

func (mounter *SafeFormatAndMount) FormatAndMount(source string, target string, fstype string, options []string) error

FormatAndMount formats the given disk, if needed, and mounts it. That is if the disk is not formatted and it is not being mounted as read-only it will format it first then mount it. Otherwise, if the disk is already formatted or it is being mounted as read-only, it will be mounted without formatting.

func (*SafeFormatAndMount) GetDiskFormat

func (mounter *SafeFormatAndMount) GetDiskFormat(disk string) (string, error)

GetDiskFormat uses 'blkid' to see if the given disk is unformated

type Subpath

type Subpath struct {
	// index of the VolumeMount for this container
	VolumeMountIndex int
	// Full path to the subpath directory on the host
	Path string
	// name of the volume that is a valid directory name.
	VolumeName string
	// Full path to the volume path
	VolumePath string
	// Path to the pod's directory, including pod UID
	PodDir string
	// Name of the container
	ContainerName string
}