package marbl

import "github.com/google/martian/v3/marbl"

Package marbl provides HTTP traffic logs streamed over websockets that can be added to any point within a Martian modifier tree. Marbl transmits HTTP logs that are serialized based on the following schema:

Frame Header FrameType uint8 MessageType uint8 ID [8]byte Payload HeaderFrame/DataFrame

Header Frame NameLen uint32 ValueLen uint32 Name variable Value variable

Data Frame Index uint32 Terminal uint8 Len uint32 Data variable

Index ¶

• type Data
• func (df Data) FrameType() FrameType
• func (df Data) String() string
• type Frame
• type FrameType
• type Handler
• func NewHandler() *Handler
• func (h *Handler) ServeHTTP(rw http.ResponseWriter, req *http.Request)
• func (h *Handler) Write(b []byte) (int, error)
• type Header
• func (hf Header) FrameType() FrameType
• func (hf Header) String() string
• type MessageType
• type Modifier
• func NewModifier(w io.Writer) *Modifier
• func (m *Modifier) ModifyRequest(req *http.Request) error
• func (m *Modifier) ModifyResponse(res *http.Response) error
• type Reader
• func NewReader(r io.Reader) *Reader
• func (r *Reader) ReadFrame() (Frame, error)
• type Stream
• func NewStream(w io.Writer) *Stream
• func (s *Stream) Close() error
• func (s *Stream) LogRequest(id string, req *http.Request) error
• func (s *Stream) LogResponse(id string, res *http.Response) error

Types ¶

type Data ¶

type Data struct {
	ID          string
	MessageType MessageType
	Index       uint32
	Terminal    bool
	Data        []byte
}

Data is the payload (body) of the request or response.

func (Data) FrameType ¶

func (df Data) FrameType() FrameType

FrameType returns DataFrame

func (Data) String ¶

func (df Data) String() string

String returns the contents of a Data frame in a format appropriate for debugging and runtime logging. The contents of the data content slice (df.Data) is not printed, instead the length of Data is printed.

type Frame ¶

type Frame interface {
	String() string
	FrameType() FrameType
}

Frame describes the interface for a frame (either Data or Header).

type FrameType ¶

type FrameType uint8

FrameType indicates whether the frame contains a Header or Data.

const (
	// UnknownFrame indicates an unknown type of Frame.
	UnknownFrame FrameType = 0x0
	// HeaderFrame indicates a frame that contains a header.
	HeaderFrame FrameType = 0x1
	// DataFrame indicates a frame that contains the payload, usually the body.
	DataFrame FrameType = 0x2
)

type Handler ¶

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

Handler exposes marbl logs over websockets.

func NewHandler ¶

func NewHandler() *Handler

NewHandler instantiates a Handler with an empty set of subscriptions.

func (*Handler) ServeHTTP ¶

func (h *Handler) ServeHTTP(rw http.ResponseWriter, req *http.Request)

func (*Handler) Write ¶

func (h *Handler) Write(b []byte) (int, error)

Write writes frames to all websocket subscribers and returns the number of bytes written and an error.

type Header ¶

type Header struct {
	ID          string
	MessageType MessageType
	Name        string
	Value       string
}

Header is either an HTTP header or meta-data pertaining to the request or response.

func (Header) FrameType ¶

func (hf Header) FrameType() FrameType

FrameType returns HeaderFrame

func (Header) String ¶

func (hf Header) String() string

String returns the contents of a Header frame in a format appropriate for debugging and runtime logging.

type MessageType ¶

type MessageType uint8

MessageType incicates whether the message represents an HTTP request or response.

const (
	// Unknown type of Message.
	Unknown MessageType = 0x0
	// Request indicates a message that contains an HTTP request.
	Request MessageType = 0x1
	// Response indicates a message that contains an HTTP response.
	Response MessageType = 0x2
)

type Modifier ¶

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

Modifier implements the Martian modifier interface so that marbl logs can be captured at any point in a Martian modifier tree.

func NewModifier ¶

func NewModifier(w io.Writer) *Modifier

NewModifier returns a marbl.Modifier initialized with a marbl.Stream.

func (*Modifier) ModifyRequest ¶

func (m *Modifier) ModifyRequest(req *http.Request) error

ModifyRequest writes an HTTP request to the log stream.

func (*Modifier) ModifyResponse ¶

func (m *Modifier) ModifyResponse(res *http.Response) error

ModifyResponse writes an HTTP response to the log stream.

type Reader ¶

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

Reader wraps a buffered Reader that reads from the io.Reader and emits Frames.

func NewReader ¶

func NewReader(r io.Reader) *Reader

NewReader returns a Reader initialized with a buffered reader.

func (*Reader) ReadFrame ¶

func (r *Reader) ReadFrame() (Frame, error)

ReadFrame reads from r, determines the FrameType, and returns either a Header or Data and an error.

type Stream ¶

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

Stream writes logs of requests and responses to a writer.

func NewStream ¶

func NewStream(w io.Writer) *Stream

NewStream initializes a Stream with an io.Writer to log requests and responses to. Upon construction, a goroutine is started that listens for frames and writes them to w.

func (*Stream) Close ¶

func (s *Stream) Close() error

Close signals Stream to stop listening for frames in the log loop and stop writing logs.

func (*Stream) LogRequest ¶

func (s *Stream) LogRequest(id string, req *http.Request) error

LogRequest writes an http.Request to Stream with an id unique for the request / response pair.

func (*Stream) LogResponse ¶

func (s *Stream) LogResponse(id string, res *http.Response) error

LogResponse writes an http.Response to Stream with an id unique for the request / response pair.

Source Files ¶

handler.go marbl.go modifier.go reader.go