layers

Documentation

Overview

Package layers provides a factory that can be used to construct layer tarballs from buildpack layer directories, extension layers, and other CNB filesystem constructs. The tarballs can be added as layers to any OCI image.

Index

• Constants
• func Extract(r io.Reader, dest string) error
• type Factory
  • func (f *Factory) DirLayer(withID string, fromDir string, createdBy string) (layer Layer, err error)
  • func (f *Factory) LauncherLayer(path string) (layer Layer, err error)
  • func (f *Factory) ProcessTypesLayer(config launch.Metadata) (layer Layer, err error)
  • func (f *Factory) SliceLayers(dir string, slices []Slice) ([]Layer, error)
  • func (f *Factory) TarLayer(withID string, fromTarPath string, createdBy string) (layer Layer, err error)
• type Layer
• type Slice

Constants

const (
	AppLayerName            = "Application Layer"
	BuildpackLayerName      = "Layer: '%s', Created by buildpack: %s"
	ExtensionLayerName      = "Layer: '%s', Created by extension: %s"
	LauncherConfigLayerName = "Buildpacks Launcher Config"
	LauncherLayerName       = "Buildpacks Application Launcher"
	ProcessTypesLayerName   = "Buildpacks Process Types"
	SBOMLayerName           = "Software Bill-of-Materials"
	SliceLayerName          = "Application Slice: %d"
)

Functions

func Extract

func Extract(r io.Reader, dest string) error

Extract extracts entries from r to the dest directory Contents of r should be an OCI layer. If dest is an empty string files with be extracted to `/` or `c:\` on unix and windows filesystems respectively.

Types

type Factory

type Factory struct {
	ArtifactsDir string // ArtifactsDir is the directory where layer files are written
	UID, GID     int    // UID and GID are used to normalize layer entries
	Logger       log.Logger
	Ctx          context.Context
	// contains filtered or unexported fields
}

func (*Factory) DirLayer

func (f *Factory) DirLayer(withID string, fromDir string, createdBy string) (layer Layer, err error)

DirLayer creates a layer from the given directory DirLayer will set the UID and GID of entries describing dir and its children (but not its parents)

to Factory.UID and Factory.GID

func (*Factory) LauncherLayer

func (f *Factory) LauncherLayer(path string) (layer Layer, err error)

LauncherLayer creates a Layer containing the launcher at path

func (*Factory) ProcessTypesLayer

func (f *Factory) ProcessTypesLayer(config launch.Metadata) (layer Layer, err error)

ProcessTypesLayer creates a Layer containing symlinks pointing to target where:

• any parents of the symlink files will also be added to the layer
• symlinks and their parent directories shall be root owned and world readable

func (*Factory) SliceLayers

func (f *Factory) SliceLayers(dir string, slices []Slice) ([]Layer, error)

SliceLayers divides dir into layers using slices using the following process: * Given n slices SliceLayers will return n+1 layers * The first n layers will contain files matched by the any Path in the nth Slice * The final layer will contain any files in dir that were not included in a previous layer Some layers may be empty

func (*Factory) TarLayer

func (f *Factory) TarLayer(withID string, fromTarPath string, createdBy string) (layer Layer, err error)

TarLayer creates a layer from the provided tar path. The provided tar may be compressed or uncompressed. TarLayer will return a layer with uncompressed data and zeroed out timestamps. FIXME: investigate if it's possible to set "no compression" in kaniko, then we can avoid decompressing layers

type Layer

type Layer struct {
	ID      string
	TarPath string
	Digest  string
	History v1.History
}

type Slice

type Slice struct {
	Paths []string `toml:"paths"`
}