diff

Documentation

Index

• Variables
• func RegisterProcessor(handler Handler)
• type Applier
• type ApplyConfig
• type ApplyOpt
  • func WithPayloads(payloads map[string]typeurl.Any) ApplyOpt
• type Comparer
• type Config
• type Handler
  • func BinaryHandler(id, returnsMediaType string, mediaTypes []string, path string, ...) Handler
  • func StaticHandler(expectedMediaType string, fn StreamProcessorInit) Handler
• type Opt
  • func WithCompressor(f func(dest io.Writer, mediaType string) (io.WriteCloser, error)) Opt
  • func WithLabels(labels map[string]string) Opt
  • func WithMediaType(m string) Opt
  • func WithReference(ref string) Opt
  • func WithSourceDateEpoch(tm *time.Time) Opt
• type RawProcessor
• type StreamProcessor
  • func GetProcessor(ctx context.Context, stream StreamProcessor, payloads map[string]typeurl.Any) (StreamProcessor, error)
  • func NewBinaryProcessor(ctx context.Context, imt, rmt string, stream StreamProcessor, name string, ...) (StreamProcessor, error)
  • func NewProcessorChain(mt string, r io.Reader) StreamProcessor
• type StreamProcessorInit

Variables

var (

	// ErrNoProcessor is returned when no stream processor is available for a media-type
	ErrNoProcessor = errors.New("no processor for media-type")
)

Functions

func RegisterProcessor

func RegisterProcessor(handler Handler)

RegisterProcessor registers a stream processor for media-types

Types

type Applier

type Applier interface {
	// Apply applies the content referred to by the given descriptor to
	// the provided mount. The method of applying is based on the
	// implementation and content descriptor. For example, in the common
	// case the descriptor is a file system difference in tar format,
	// that tar would be applied on top of the mounts.
	Apply(ctx context.Context, desc ocispec.Descriptor, mount []mount.Mount, opts ...ApplyOpt) (ocispec.Descriptor, error)
}

Applier allows applying diffs between mounts

type ApplyConfig

type ApplyConfig struct {
	// ProcessorPayloads specifies the payload sent to various processors
	ProcessorPayloads map[string]typeurl.Any
}

ApplyConfig is used to hold parameters needed for a apply operation

type ApplyOpt

type ApplyOpt func(context.Context, ocispec.Descriptor, *ApplyConfig) error

ApplyOpt is used to configure an Apply operation

func WithPayloads

func WithPayloads(payloads map[string]typeurl.Any) ApplyOpt

WithPayloads sets the apply processor payloads to the config

type Comparer

type Comparer interface {
	// Compare computes the difference between two mounts and returns a
	// descriptor for the computed diff. The options can provide
	// a ref which can be used to track the content creation of the diff.
	// The media type which is used to determine the format of the created
	// content can also be provided as an option.
	Compare(ctx context.Context, lower, upper []mount.Mount, opts ...Opt) (ocispec.Descriptor, error)
}

Comparer allows creation of filesystem diffs between mounts

type Config

type Config struct {
	// MediaType is the type of diff to generate
	// Default depends on the differ,
	// i.e. application/vnd.oci.image.layer.v1.tar+gzip
	MediaType string

	// Reference is the content upload reference
	// Default will use a random reference string
	Reference string

	// Labels are the labels to apply to the generated content
	Labels map[string]string

	// Compressor is a function to compress the diff stream
	// instead of the default gzip compressor. Differ passes
	// the MediaType of the target diff content to the compressor.
	// When using this config, MediaType must be specified as well.
	Compressor func(dest io.Writer, mediaType string) (io.WriteCloser, error)

	// SourceDateEpoch specifies the SOURCE_DATE_EPOCH without touching the env vars.
	SourceDateEpoch *time.Time
}

Config is used to hold parameters needed for a diff operation

type Handler

type Handler func(ctx context.Context, mediaType string) (StreamProcessorInit, bool)

Handler checks a media-type and initializes the processor

func BinaryHandler

func BinaryHandler(id, returnsMediaType string, mediaTypes []string, path string, args, env []string) Handler

BinaryHandler creates a new stream processor handler which calls out to the given binary. The id is used to identify the stream processor and allows the caller to send payloads specific for that stream processor (i.e. decryption keys for decrypt stream processor). The binary will be called for the provided mediaTypes and return the given media type.

func StaticHandler

func StaticHandler(expectedMediaType string, fn StreamProcessorInit) Handler

StaticHandler returns the processor init func for a static media-type

type Opt

type Opt func(*Config) error

Opt is used to configure a diff operation

func WithCompressor

func WithCompressor(f func(dest io.Writer, mediaType string) (io.WriteCloser, error)) Opt

WithCompressor sets the function to be used to compress the diff stream.

func WithLabels

func WithLabels(labels map[string]string) Opt

WithLabels is used to set content labels on the created diff content.

func WithMediaType

func WithMediaType(m string) Opt

WithMediaType sets the media type to use for creating the diff, without specifying the differ will choose a default.

func WithReference

func WithReference(ref string) Opt

WithReference is used to set the content upload reference used by the diff operation. This allows the caller to track the upload through the content store.

func WithSourceDateEpoch

func WithSourceDateEpoch(tm *time.Time) Opt

WithSourceDateEpoch specifies the timestamp used for whiteouts to provide control for reproducibility. See also https://reproducible-builds.org/docs/source-date-epoch/ .

type RawProcessor

type RawProcessor interface {
	// File returns the fd for the read stream of the underlying processor
	File() *os.File
}

RawProcessor provides access to direct fd for processing

type StreamProcessor

type StreamProcessor interface {
	io.ReadCloser

	// MediaType is the resulting media-type that the processor processes the stream into
	MediaType() string
}

StreamProcessor handles processing a content stream and transforming it into a different media-type

func GetProcessor

func GetProcessor(ctx context.Context, stream StreamProcessor, payloads map[string]typeurl.Any) (StreamProcessor, error)

GetProcessor returns the processor for a media-type

func NewBinaryProcessor

func NewBinaryProcessor(ctx context.Context, imt, rmt string, stream StreamProcessor, name string, args, env []string, payload typeurl.Any) (StreamProcessor, error)

NewBinaryProcessor returns a binary processor for use with processing content streams

func NewProcessorChain

func NewProcessorChain(mt string, r io.Reader) StreamProcessor

NewProcessorChain initialized the root StreamProcessor

type StreamProcessorInit

type StreamProcessorInit func(ctx context.Context, stream StreamProcessor, payloads map[string]typeurl.Any) (StreamProcessor, error)

StreamProcessorInit returns the initialized stream processor