squashfs

Documentation

Overview

This package is a small go "library" (read: exec wrapper) around the mksquashfs binary that provides some useful primitives.

This file was initially copied from go-diskfs [1]. The copied portion is Copyright (c) 2017 Avi Deitcher and licensed under the terms of the MIT license [2].

[1] https://github.com/diskfs/go-diskfs/filesystem/squashfs/superblock.go
[2] https://opensource.org/licenses/MIT

Index

• Constants
• func ConfirmExistingVerityDeviceHash(devicePath string, rootHash string, allowVerityFailure bool) error
• func ExtractSingleSquash(squashFile string, extractDir string) error
• func ExtractSingleSquashPolicy(squashFile, extractDir string, policy *ExtractPolicy) error
• func GenerateSquashfsMediaType(comp SquashfsCompression, verity VerityMetadata) string
• func GuestMount(squashFile string, mountpoint string) error
• func HostMount(squashfs string, mountpoint string, rootHash string) error
• func IsSquashfsMediaType(mediaType string) bool
• func MakeSquashfs(tempdir string, rootfs string, eps *ExcludePaths, verity VerityMetadata) (io.ReadCloser, string, string, error)
• func Mount(squashfs, mountpoint, rootHash string) error
• func Umount(mountpoint string) error
• type ExcludePaths
  • func NewExcludePaths() *ExcludePaths
  • func (eps *ExcludePaths) AddExclude(p string)
  • func (eps *ExcludePaths) AddInclude(orig string, isDir bool)
  • func (eps *ExcludePaths) String() (string, error)
• type ExtractPolicy
  • func NewExtractPolicy(args ...string) (*ExtractPolicy, error)
• type KernelExtractor
  • func (k *KernelExtractor) IsAvailable() error
  • func (k *KernelExtractor) Mount(squashFile, extractDir string) error
  • func (k *KernelExtractor) Name() string
• type SquashExtractor
• type SquashFuseExtractor
  • func (k *SquashFuseExtractor) IsAvailable() error
  • func (k *SquashFuseExtractor) Mount(squashFile, extractDir string) error
  • func (k *SquashFuseExtractor) Name() string
• type SquashfsCompression
• type UnsquashfsExtractor
  • func (k *UnsquashfsExtractor) IsAvailable() error
  • func (k *UnsquashfsExtractor) Mount(squashFile, extractDir string) error
  • func (k *UnsquashfsExtractor) Name() string
• type VerityMetadata
  • func HasVerityMetadata(mediaType string) VerityMetadata

Constants

const (
	BaseMediaTypeLayerSquashfs = "application/vnd.stacker.image.layer.squashfs"

	GzipCompression SquashfsCompression = "gzip"
	ZstdCompression SquashfsCompression = "zstd"

	VerityMetadataPresent VerityMetadata = true
	VerityMetadataMissing VerityMetadata = false
)

const VerityRootHashAnnotation = "io.stackeroci.stacker.squashfs_verity_root_hash"

Functions

func ConfirmExistingVerityDeviceHash

func ConfirmExistingVerityDeviceHash(devicePath string, rootHash string, allowVerityFailure bool) error

func ExtractSingleSquash

func ExtractSingleSquash(squashFile string, extractDir string) error

ExtractSingleSquash - extract the squashFile to extractDir Initialize a extractPolicy struct and then call ExtractSingleSquashPolicy wik()th that.

func ExtractSingleSquashPolicy

func ExtractSingleSquashPolicy(squashFile, extractDir string, policy *ExtractPolicy) error

ExtractSingleSquashPolicy - extract squashfile to extractDir

func GenerateSquashfsMediaType

func GenerateSquashfsMediaType(comp SquashfsCompression, verity VerityMetadata) string

func GuestMount

func GuestMount(squashFile string, mountpoint string) error

Mount a filesystem as container root, without host root privileges. We do this using squashfuse.

func HostMount

func HostMount(squashfs string, mountpoint string, rootHash string) error

func IsSquashfsMediaType

func IsSquashfsMediaType(mediaType string) bool

func MakeSquashfs

func MakeSquashfs(tempdir string, rootfs string, eps *ExcludePaths, verity VerityMetadata) (io.ReadCloser, string, string, error)

func Mount

func Mount(squashfs, mountpoint, rootHash string) error

func Umount

func Umount(mountpoint string) error

Types

type ExcludePaths

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

ExcludePaths represents a list of paths to exclude in a squashfs listing. Users should do something like filepath.Walk() over the whole filesystem, calling AddExclude() or AddInclude() based on whether they want to include or exclude a particular file. Note that if e.g. /usr is excluded, then everyting underneath is also implicitly excluded. The AddExclude()/AddInclude() methods do the math to figure out what is the correct set of things to exclude or include based on what paths have been previously included or excluded.

func NewExcludePaths

func NewExcludePaths() *ExcludePaths

func (*ExcludePaths) AddExclude

func (eps *ExcludePaths) AddExclude(p string)

func (*ExcludePaths) AddInclude

func (eps *ExcludePaths) AddInclude(orig string, isDir bool)

func (*ExcludePaths) String

func (eps *ExcludePaths) String() (string, error)

type ExtractPolicy

type ExtractPolicy struct {
	Extractors []SquashExtractor
	Extractor  SquashExtractor
	Excuses    map[string]error
	// contains filtered or unexported fields
}

func NewExtractPolicy

func NewExtractPolicy(args ...string) (*ExtractPolicy, error)

type KernelExtractor

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

func (*KernelExtractor) IsAvailable

func (k *KernelExtractor) IsAvailable() error

func (*KernelExtractor) Mount

func (k *KernelExtractor) Mount(squashFile, extractDir string) error

func (*KernelExtractor) Name

func (k *KernelExtractor) Name() string

type SquashExtractor

type SquashExtractor interface {
	Name() string
	IsAvailable() error
	// Mount - Mount or extract path to dest.
	//   Return nil on "already extracted"
	//   Return error on failure.
	Mount(path, dest string) error
}

type SquashFuseExtractor

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

func (*SquashFuseExtractor) IsAvailable

func (k *SquashFuseExtractor) IsAvailable() error

func (*SquashFuseExtractor) Mount

func (k *SquashFuseExtractor) Mount(squashFile, extractDir string) error

func (*SquashFuseExtractor) Name

func (k *SquashFuseExtractor) Name() string

type SquashfsCompression

type SquashfsCompression string

type UnsquashfsExtractor

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

func (*UnsquashfsExtractor) IsAvailable

func (k *UnsquashfsExtractor) IsAvailable() error

func (*UnsquashfsExtractor) Mount

func (k *UnsquashfsExtractor) Mount(squashFile, extractDir string) error

func (*UnsquashfsExtractor) Name

func (k *UnsquashfsExtractor) Name() string

type VerityMetadata

type VerityMetadata bool

func HasVerityMetadata

func HasVerityMetadata(mediaType string) VerityMetadata