Replace godep with dep

vendor/k8s.io/apiserver/pkg/endpoints/handlers/proxy.go

@@ -0,0 +1,293 @@
+/*
+Copyright 2014 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package handlers
+
+import (
+	"context"
+	"errors"
+	"io"
+	"math/rand"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"path"
+	"strings"
+	"time"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/httpstream"
+	"k8s.io/apimachinery/pkg/util/net"
+	proxyutil "k8s.io/apimachinery/pkg/util/proxy"
+	"k8s.io/apiserver/pkg/endpoints/handlers/responsewriters"
+	"k8s.io/apiserver/pkg/endpoints/metrics"
+	"k8s.io/apiserver/pkg/endpoints/request"
+	"k8s.io/apiserver/pkg/registry/rest"
+	"k8s.io/apiserver/pkg/server/httplog"
+
+	"github.com/golang/glog"
+)
+
+// ProxyHandler provides a http.Handler which will proxy traffic to locations
+// specified by items implementing Redirector.
+type ProxyHandler struct {
+	Prefix     string
+	Storage    map[string]rest.Storage
+	Serializer runtime.NegotiatedSerializer
+	Mapper     request.RequestContextMapper
+}
+
+func (r *ProxyHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	reqStart := time.Now()
+	proxyHandlerTraceID := rand.Int63()
+
+	var verb, apiResource, subresource, scope string
+	var httpCode int
+
+	defer func() {
+		responseLength := 0
+		if rw, ok := w.(*metrics.ResponseWriterDelegator); ok {
+			responseLength = rw.ContentLength()
+		}
+		metrics.Monitor(
+			verb, apiResource, subresource, scope,
+			net.GetHTTPClient(req),
+			w.Header().Get("Content-Type"),
+			httpCode, responseLength, reqStart,
+		)
+	}()
+
+	ctx, ok := r.Mapper.Get(req)
+	if !ok {
+		responsewriters.InternalError(w, req, errors.New("Error getting request context"))
+		httpCode = http.StatusInternalServerError
+		return
+	}
+
+	requestInfo, ok := request.RequestInfoFrom(ctx)
+	if !ok {
+		responsewriters.InternalError(w, req, errors.New("Error getting RequestInfo from context"))
+		httpCode = http.StatusInternalServerError
+		return
+	}
+	if !requestInfo.IsResourceRequest {
+		responsewriters.NotFound(w, req)
+		httpCode = http.StatusNotFound
+		return
+	}
+	verb = requestInfo.Verb
+	namespace, resource, subresource, parts := requestInfo.Namespace, requestInfo.Resource, requestInfo.Subresource, requestInfo.Parts
+	scope = "cluster"
+	if namespace != "" {
+		scope = "namespace"
+	}
+	if requestInfo.Name != "" {
+		scope = "resource"
+	}
+
+	ctx = request.WithNamespace(ctx, namespace)
+	if len(parts) < 2 {
+		responsewriters.NotFound(w, req)
+		httpCode = http.StatusNotFound
+		return
+	}
+	id := parts[1]
+	remainder := ""
+	if len(parts) > 2 {
+		proxyParts := parts[2:]
+		remainder = strings.Join(proxyParts, "/")
+		if strings.HasSuffix(req.URL.Path, "/") {
+			// The original path had a trailing slash, which has been stripped
+			// by KindAndNamespace(). We should add it back because some
+			// servers (like etcd) require it.
+			remainder = remainder + "/"
+		}
+	}
+	storage, ok := r.Storage[resource]
+	if !ok {
+		httplog.LogOf(req, w).Addf("'%v' has no storage object", resource)
+		responsewriters.NotFound(w, req)
+		httpCode = http.StatusNotFound
+		return
+	}
+	apiResource = resource
+
+	gv := schema.GroupVersion{Group: requestInfo.APIGroup, Version: requestInfo.APIVersion}
+
+	redirector, ok := storage.(rest.Redirector)
+	if !ok {
+		httplog.LogOf(req, w).Addf("'%v' is not a redirector", resource)
+		httpCode = responsewriters.ErrorNegotiated(ctx, apierrors.NewMethodNotSupported(schema.GroupResource{Resource: resource}, "proxy"), r.Serializer, gv, w, req)
+		return
+	}
+
+	location, roundTripper, err := redirector.ResourceLocation(ctx, id)
+	if err != nil {
+		httplog.LogOf(req, w).Addf("Error getting ResourceLocation: %v", err)
+		httpCode = responsewriters.ErrorNegotiated(ctx, err, r.Serializer, gv, w, req)
+		return
+	}
+	if location == nil {
+		httplog.LogOf(req, w).Addf("ResourceLocation for %v returned nil", id)
+		responsewriters.NotFound(w, req)
+		httpCode = http.StatusNotFound
+		return
+	}
+
+	if roundTripper != nil {
+		glog.V(5).Infof("[%x: %v] using transport %T...", proxyHandlerTraceID, req.URL, roundTripper)
+	}
+
+	// Default to http
+	if location.Scheme == "" {
+		location.Scheme = "http"
+	}
+	// Add the subpath
+	if len(remainder) > 0 {
+		location.Path = singleJoiningSlash(location.Path, remainder)
+	}
+	// Start with anything returned from the storage, and add the original request's parameters
+	values := location.Query()
+	for k, vs := range req.URL.Query() {
+		for _, v := range vs {
+			values.Add(k, v)
+		}
+	}
+	location.RawQuery = values.Encode()
+
+	// WithContext creates a shallow clone of the request with the new context.
+	newReq := req.WithContext(context.Background())
+	newReq.Header = net.CloneHeader(req.Header)
+	newReq.URL = location
+
+	// TODO convert this entire proxy to an UpgradeAwareProxy similar to
+	// https://github.com/openshift/origin/blob/master/pkg/util/httpproxy/upgradeawareproxy.go.
+	// That proxy needs to be modified to support multiple backends, not just 1.
+	if r.tryUpgrade(ctx, w, req, newReq, location, roundTripper, gv) {
+		return
+	}
+
+	// Redirect requests of the form "/{resource}/{name}" to "/{resource}/{name}/"
+	// This is essentially a hack for http://issue.k8s.io/4958.
+	// Note: Keep this code after tryUpgrade to not break that flow.
+	if len(parts) == 2 && !strings.HasSuffix(req.URL.Path, "/") {
+		var queryPart string
+		if len(req.URL.RawQuery) > 0 {
+			queryPart = "?" + req.URL.RawQuery
+		}
+		w.Header().Set("Location", req.URL.Path+"/"+queryPart)
+		w.WriteHeader(http.StatusMovedPermanently)
+		return
+	}
+
+	start := time.Now()
+	glog.V(4).Infof("[%x] Beginning proxy %s...", proxyHandlerTraceID, req.URL)
+	defer func() {
+		glog.V(4).Infof("[%x] Proxy %v finished %v.", proxyHandlerTraceID, req.URL, time.Now().Sub(start))
+	}()
+
+	proxy := httputil.NewSingleHostReverseProxy(&url.URL{Scheme: location.Scheme, Host: location.Host})
+	alreadyRewriting := false
+	if roundTripper != nil {
+		_, alreadyRewriting = roundTripper.(*proxyutil.Transport)
+		glog.V(5).Infof("[%x] Not making a rewriting transport for proxy %s...", proxyHandlerTraceID, req.URL)
+	}
+	if !alreadyRewriting {
+		glog.V(5).Infof("[%x] making a transport for proxy %s...", proxyHandlerTraceID, req.URL)
+		prepend := path.Join(r.Prefix, resource, id)
+		if len(namespace) > 0 {
+			prepend = path.Join(r.Prefix, "namespaces", namespace, resource, id)
+		}
+		pTransport := &proxyutil.Transport{
+			Scheme:       req.URL.Scheme,
+			Host:         req.URL.Host,
+			PathPrepend:  prepend,
+			RoundTripper: roundTripper,
+		}
+		roundTripper = pTransport
+	}
+	proxy.Transport = roundTripper
+	proxy.FlushInterval = 200 * time.Millisecond
+	proxy.ServeHTTP(w, newReq)
+}
+
+// tryUpgrade returns true if the request was handled.
+func (r *ProxyHandler) tryUpgrade(ctx request.Context, w http.ResponseWriter, req, newReq *http.Request, location *url.URL, transport http.RoundTripper, gv schema.GroupVersion) bool {
+	if !httpstream.IsUpgradeRequest(req) {
+		return false
+	}
+	// Only append X-Forwarded-For in the upgrade path, since httputil.NewSingleHostReverseProxy
+	// handles this in the non-upgrade path.
+	net.AppendForwardedForHeader(newReq)
+
+	backendConn, err := proxyutil.DialURL(location, transport)
+	if err != nil {
+		responsewriters.ErrorNegotiated(ctx, err, r.Serializer, gv, w, req)
+		return true
+	}
+	defer backendConn.Close()
+
+	// TODO should we use _ (a bufio.ReadWriter) instead of requestHijackedConn
+	// when copying between the client and the backend? Docker doesn't when they
+	// hijack, just for reference...
+	requestHijackedConn, _, err := w.(http.Hijacker).Hijack()
+	if err != nil {
+		responsewriters.ErrorNegotiated(ctx, err, r.Serializer, gv, w, req)
+		return true
+	}
+	defer requestHijackedConn.Close()
+
+	if err = newReq.Write(backendConn); err != nil {
+		responsewriters.ErrorNegotiated(ctx, err, r.Serializer, gv, w, req)
+		return true
+	}
+
+	done := make(chan struct{}, 2)
+
+	go func() {
+		_, err := io.Copy(backendConn, requestHijackedConn)
+		if err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
+			glog.Errorf("Error proxying data from client to backend: %v", err)
+		}
+		done <- struct{}{}
+	}()
+
+	go func() {
+		_, err := io.Copy(requestHijackedConn, backendConn)
+		if err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
+			glog.Errorf("Error proxying data from backend to client: %v", err)
+		}
+		done <- struct{}{}
+	}()
+
+	<-done
+	return true
+}
+
+// borrowed from net/http/httputil/reverseproxy.go
+func singleJoiningSlash(a, b string) string {
+	aslash := strings.HasSuffix(a, "/")
+	bslash := strings.HasPrefix(b, "/")
+	switch {
+	case aslash && bslash:
+		return a + b[1:]
+	case !aslash && !bslash:
+		return a + "/" + b
+	}
+	return a + b
+}