Update etcd client to 3.3.9

vendor/github.com/tmc/grpc-websocket-proxy/wsproxy/websocket_proxy.go

@@ -0,0 +1,254 @@
+package wsproxy
+
+import (
+	"bufio"
+	"io"
+	"net/http"
+	"strings"
+
+	"github.com/gorilla/websocket"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/net/context"
+)
+
+// MethodOverrideParam defines the special URL parameter that is translated into the subsequent proxied streaming http request's method.
+//
+// Deprecated: it is preferable to use the Options parameters to WebSocketProxy to supply parameters.
+var MethodOverrideParam = "method"
+
+// TokenCookieName defines the cookie name that is translated to an 'Authorization: Bearer' header in the streaming http request's headers.
+//
+// Deprecated: it is preferable to use the Options parameters to WebSocketProxy to supply parameters.
+var TokenCookieName = "token"
+
+// RequestMutatorFunc can supply an alternate outgoing request.
+type RequestMutatorFunc func(incoming *http.Request, outgoing *http.Request) *http.Request
+
+// Proxy provides websocket transport upgrade to compatible endpoints.
+type Proxy struct {
+	h                   http.Handler
+	logger              Logger
+	methodOverrideParam string
+	tokenCookieName     string
+	requestMutator      RequestMutatorFunc
+}
+
+// Logger collects log messages.
+type Logger interface {
+	Warnln(...interface{})
+	Debugln(...interface{})
+}
+
+func (p *Proxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if !websocket.IsWebSocketUpgrade(r) {
+		p.h.ServeHTTP(w, r)
+		return
+	}
+	p.proxy(w, r)
+}
+
+// Option allows customization of the proxy.
+type Option func(*Proxy)
+
+// WithMethodParamOverride allows specification of the special http parameter that is used in the proxied streaming request.
+func WithMethodParamOverride(param string) Option {
+	return func(p *Proxy) {
+		p.methodOverrideParam = param
+	}
+}
+
+// WithTokenCookieName allows specification of the cookie that is supplied as an upstream 'Authorization: Bearer' http header.
+func WithTokenCookieName(param string) Option {
+	return func(p *Proxy) {
+		p.tokenCookieName = param
+	}
+}
+
+// WithRequestMutator allows a custom RequestMutatorFunc to be supplied.
+func WithRequestMutator(fn RequestMutatorFunc) Option {
+	return func(p *Proxy) {
+		p.requestMutator = fn
+	}
+}
+
+// WithLogger allows a custom FieldLogger to be supplied
+func WithLogger(logger Logger) Option {
+	return func(p *Proxy) {
+		p.logger = logger
+	}
+}
+
+// WebsocketProxy attempts to expose the underlying handler as a bidi websocket stream with newline-delimited
+// JSON as the content encoding.
+//
+// The HTTP Authorization header is either populated from the Sec-Websocket-Protocol field or by a cookie.
+// The cookie name is specified by the TokenCookieName value.
+//
+// example:
+//   Sec-Websocket-Protocol: Bearer, foobar
+// is converted to:
+//   Authorization: Bearer foobar
+//
+// Method can be overwritten with the MethodOverrideParam get parameter in the requested URL
+func WebsocketProxy(h http.Handler, opts ...Option) http.Handler {
+	p := &Proxy{
+		h:                   h,
+		logger:              logrus.New(),
+		methodOverrideParam: MethodOverrideParam,
+		tokenCookieName:     TokenCookieName,
+	}
+	for _, o := range opts {
+		o(p)
+	}
+	return p
+}
+
+// TODO(tmc): allow modification of upgrader settings?
+var upgrader = websocket.Upgrader{
+	ReadBufferSize:  1024,
+	WriteBufferSize: 1024,
+	CheckOrigin:     func(r *http.Request) bool { return true },
+}
+
+func isClosedConnError(err error) bool {
+	str := err.Error()
+	if strings.Contains(str, "use of closed network connection") {
+		return true
+	}
+	return websocket.IsCloseError(err, websocket.CloseNormalClosure, websocket.CloseGoingAway)
+}
+
+func (p *Proxy) proxy(w http.ResponseWriter, r *http.Request) {
+	var responseHeader http.Header
+	// If Sec-WebSocket-Protocol starts with "Bearer", respond in kind.
+	// TODO(tmc): consider customizability/extension point here.
+	if strings.HasPrefix(r.Header.Get("Sec-WebSocket-Protocol"), "Bearer") {
+		responseHeader = http.Header{
+			"Sec-WebSocket-Protocol": []string{"Bearer"},
+		}
+	}
+	conn, err := upgrader.Upgrade(w, r, responseHeader)
+	if err != nil {
+		p.logger.Warnln("error upgrading websocket:", err)
+		return
+	}
+	defer conn.Close()
+
+	ctx, cancelFn := context.WithCancel(context.Background())
+	defer cancelFn()
+
+	requestBodyR, requestBodyW := io.Pipe()
+	request, err := http.NewRequest(r.Method, r.URL.String(), requestBodyR)
+	if err != nil {
+		p.logger.Warnln("error preparing request:", err)
+		return
+	}
+	if swsp := r.Header.Get("Sec-WebSocket-Protocol"); swsp != "" {
+		request.Header.Set("Authorization", strings.Replace(swsp, "Bearer, ", "Bearer ", 1))
+	}
+	// If token cookie is present, populate Authorization header from the cookie instead.
+	if cookie, err := r.Cookie(p.tokenCookieName); err == nil {
+		request.Header.Set("Authorization", "Bearer "+cookie.Value)
+	}
+	if m := r.URL.Query().Get(p.methodOverrideParam); m != "" {
+		request.Method = m
+	}
+
+	if p.requestMutator != nil {
+		request = p.requestMutator(r, request)
+	}
+
+	responseBodyR, responseBodyW := io.Pipe()
+	response := newInMemoryResponseWriter(responseBodyW)
+	go func() {
+		<-ctx.Done()
+		p.logger.Debugln("closing pipes")
+		requestBodyW.CloseWithError(io.EOF)
+		responseBodyW.CloseWithError(io.EOF)
+		response.closed <- true
+	}()
+
+	go func() {
+		defer cancelFn()
+		p.h.ServeHTTP(response, request)
+	}()
+
+	// read loop -- take messages from websocket and write to http request
+	go func() {
+		defer func() {
+			cancelFn()
+		}()
+		for {
+			select {
+			case <-ctx.Done():
+				p.logger.Debugln("read loop done")
+				return
+			default:
+			}
+			p.logger.Debugln("[read] reading from socket.")
+			_, payload, err := conn.ReadMessage()
+			if err != nil {
+				if isClosedConnError(err) {
+					p.logger.Debugln("[read] websocket closed:", err)
+					return
+				}
+				p.logger.Warnln("error reading websocket message:", err)
+				return
+			}
+			p.logger.Debugln("[read] read payload:", string(payload))
+			p.logger.Debugln("[read] writing to requestBody:")
+			n, err := requestBodyW.Write(payload)
+			requestBodyW.Write([]byte("\n"))
+			p.logger.Debugln("[read] wrote to requestBody", n)
+			if err != nil {
+				p.logger.Warnln("[read] error writing message to upstream http server:", err)
+				return
+			}
+		}
+	}()
+	// write loop -- take messages from response and write to websocket
+	scanner := bufio.NewScanner(responseBodyR)
+	for scanner.Scan() {
+		if len(scanner.Bytes()) == 0 {
+			p.logger.Warnln("[write] empty scan", scanner.Err())
+			continue
+		}
+		p.logger.Debugln("[write] scanned", scanner.Text())
+		if err = conn.WriteMessage(websocket.TextMessage, scanner.Bytes()); err != nil {
+			p.logger.Warnln("[write] error writing websocket message:", err)
+			return
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		p.logger.Warnln("scanner err:", err)
+	}
+}
+
+type inMemoryResponseWriter struct {
+	io.Writer
+	header http.Header
+	code   int
+	closed chan bool
+}
+
+func newInMemoryResponseWriter(w io.Writer) *inMemoryResponseWriter {
+	return &inMemoryResponseWriter{
+		Writer: w,
+		header: http.Header{},
+		closed: make(chan bool, 1),
+	}
+}
+
+func (w *inMemoryResponseWriter) Write(b []byte) (int, error) {
+	return w.Writer.Write(b)
+}
+func (w *inMemoryResponseWriter) Header() http.Header {
+	return w.header
+}
+func (w *inMemoryResponseWriter) WriteHeader(code int) {
+	w.code = code
+}
+func (w *inMemoryResponseWriter) CloseNotify() <-chan bool {
+	return w.closed
+}
+func (w *inMemoryResponseWriter) Flush() {}