mirror of
https://github.com/k3s-io/kubernetes.git
synced 2025-10-31 13:50:01 +00:00
278 lines
8.3 KiB
Go
278 lines
8.3 KiB
Go
/*
|
|
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 apiserver
|
|
|
|
import (
|
|
"errors"
|
|
"io"
|
|
"math/rand"
|
|
"net/http"
|
|
"net/http/httputil"
|
|
"net/url"
|
|
"path"
|
|
"strings"
|
|
"time"
|
|
|
|
"k8s.io/kubernetes/pkg/api"
|
|
apierrors "k8s.io/kubernetes/pkg/api/errors"
|
|
"k8s.io/kubernetes/pkg/api/rest"
|
|
"k8s.io/kubernetes/pkg/apiserver/metrics"
|
|
"k8s.io/kubernetes/pkg/httplog"
|
|
"k8s.io/kubernetes/pkg/runtime"
|
|
"k8s.io/kubernetes/pkg/runtime/schema"
|
|
"k8s.io/kubernetes/pkg/util/httpstream"
|
|
"k8s.io/kubernetes/pkg/util/net"
|
|
proxyutil "k8s.io/kubernetes/pkg/util/proxy"
|
|
|
|
"github.com/golang/glog"
|
|
"k8s.io/kubernetes/pkg/apiserver/request"
|
|
)
|
|
|
|
// 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 api.RequestContextMapper
|
|
}
|
|
|
|
func (r *ProxyHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
|
|
proxyHandlerTraceID := rand.Int63()
|
|
|
|
var verb string
|
|
var apiResource string
|
|
var httpCode int
|
|
reqStart := time.Now()
|
|
defer metrics.Monitor(&verb, &apiResource, net.GetHTTPClient(req), w.Header().Get("Content-Type"), httpCode, reqStart)
|
|
|
|
ctx, ok := r.mapper.Get(req)
|
|
if !ok {
|
|
internalError(w, req, errors.New("Error getting request context"))
|
|
httpCode = http.StatusInternalServerError
|
|
return
|
|
}
|
|
|
|
requestInfo, ok := request.RequestInfoFrom(ctx)
|
|
if !ok {
|
|
internalError(w, req, errors.New("Error getting RequestInfo from context"))
|
|
httpCode = http.StatusInternalServerError
|
|
return
|
|
}
|
|
if !requestInfo.IsResourceRequest {
|
|
notFound(w, req)
|
|
httpCode = http.StatusNotFound
|
|
return
|
|
}
|
|
verb = requestInfo.Verb
|
|
namespace, resource, parts := requestInfo.Namespace, requestInfo.Resource, requestInfo.Parts
|
|
|
|
ctx = api.WithNamespace(ctx, namespace)
|
|
if len(parts) < 2 {
|
|
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)
|
|
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 = errorNegotiated(apierrors.NewMethodNotSupported(api.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 = errorNegotiated(err, r.serializer, gv, w, req)
|
|
return
|
|
}
|
|
if location == nil {
|
|
httplog.LogOf(req, w).Addf("ResourceLocation for %v returned nil", id)
|
|
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()
|
|
|
|
newReq, err := http.NewRequest(req.Method, location.String(), req.Body)
|
|
if err != nil {
|
|
httpCode = errorNegotiated(err, r.serializer, gv, w, req)
|
|
return
|
|
}
|
|
httpCode = http.StatusOK
|
|
newReq.Header = req.Header
|
|
newReq.ContentLength = req.ContentLength
|
|
// Copy the TransferEncoding is for future-proofing. Currently Go only supports "chunked" and
|
|
// it can determine the TransferEncoding based on ContentLength and the Body.
|
|
newReq.TransferEncoding = req.TransferEncoding
|
|
|
|
// 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(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(w http.ResponseWriter, req, newReq *http.Request, location *url.URL, transport http.RoundTripper, gv schema.GroupVersion) bool {
|
|
if !httpstream.IsUpgradeRequest(req) {
|
|
return false
|
|
}
|
|
backendConn, err := proxyutil.DialURL(location, transport)
|
|
if err != nil {
|
|
errorNegotiated(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 {
|
|
errorNegotiated(err, r.serializer, gv, w, req)
|
|
return true
|
|
}
|
|
defer requestHijackedConn.Close()
|
|
|
|
if err = newReq.Write(backendConn); err != nil {
|
|
errorNegotiated(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
|
|
}
|