image

Documentation

Index

• Constants
• func ConvertQcow2ToRaw(src, dest string) error
• func ConvertQcow2ToRawStream(url *url.URL, dest string) error
• func Validate(image, format string) error
• type Header
  • func (h Header) Match(b []byte) bool
  • func (h Header) Size(b []byte) (int64, error)
• type Headers
  • func CopyKnownHdrs() Headers
• type QEMUOperations
  • func NewQEMUOperations() QEMUOperations

Constants

const (
	// ExtImg is a constant for the .img extenstion
	ExtImg = ".img"
	// ExtIso is a constant for the .iso extenstion
	ExtIso = ".iso"
	// ExtGz is a constant for the .gz extenstion
	ExtGz = ".gz"
	// ExtQcow2 is a constant for the .qcow2 extenstion
	ExtQcow2 = ".qcow2"
	// ExtTar is a constant for the .tar extenstion
	ExtTar = ".tar"
	// ExtXz is a constant for the .xz extenstion
	ExtXz = ".xz"
	// ExtTarXz is a constant for the .tar.xz extenstion
	ExtTarXz = ExtTar + ExtXz
	// ExtTarGz is a constant for the .tar.gz extenstion
	ExtTarGz = ExtTar + ExtGz
)

const MaxExpectedHdrSize = 512

MaxExpectedHdrSize defines the Size of buffer used to read file headers. Note: this is the size of tar's header. If a larger number is used the tar unarchive operation

creates the destination file too large, by the difference between this const and 512.

Functions

func ConvertQcow2ToRaw

func ConvertQcow2ToRaw(src, dest string) error

ConvertQcow2ToRaw is a wrapper for qemu-img convert which takes a qcow2 file (specified by src) and converts it to a raw image (written to the provided dest file)

func ConvertQcow2ToRawStream

func ConvertQcow2ToRawStream(url *url.URL, dest string) error

ConvertQcow2ToRawStream converts an http accessible qcow2 image to raw format without locally caching the qcow2 image

func Validate

func Validate(image, format string) error

Validate does basic validation of a qemu image

Types

type Header

type Header struct {
	Format string

	SizeOff int // in bytes
	SizeLen int // in bytes
	// contains filtered or unexported fields
}

Header represents our parameters for a file format header

func (Header) Match

func (h Header) Match(b []byte) bool

Match performs a check to see if the provided byte slice matches the bytes in our header data

func (Header) Size

func (h Header) Size(b []byte) (int64, error)

Size uses the Header receiver offset and length fields to extract, from the passed-in file header slice (b), the size of the original file. It is not guaranteed that the header is known to cdi and thus 0 may be returned as the size.

type Headers

type Headers map[string]Header

Headers provides a map for header info, key is file format, eg. "gz" or "tar", value is metadata describing the layout for this hdr

func CopyKnownHdrs

func CopyKnownHdrs() Headers

CopyKnownHdrs performs a simple map copy since := assignment copies the reference to the map, not contents.

type QEMUOperations

type QEMUOperations interface {
	ConvertQcow2ToRaw(string, string) error
	ConvertQcow2ToRawStream(*url.URL, string) error
	Validate(string, string) error
}

QEMUOperations defines the interface for executing qemu subprocesses

func NewQEMUOperations

func NewQEMUOperations() QEMUOperations

NewQEMUOperations returns the default implementation of QEMUOperations