mirror of
https://github.com/optim-enterprises-bv/kubernetes.git
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e2b645ec15
To proxy traffic to anything that implements ResourceLocation. Currently, this is only services. This is easily extensible to minions (would supercede existing mechanism) and pods.
189 lines
4.7 KiB
Go
189 lines
4.7 KiB
Go
/*
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Copyright 2014 Google Inc. All rights reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package apiserver
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import (
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"bytes"
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"fmt"
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"io/ioutil"
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"net/http"
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"net/http/httputil"
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"net/url"
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"path"
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"strings"
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"github.com/GoogleCloudPlatform/kubernetes/pkg/httplog"
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"code.google.com/p/go.net/html"
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"code.google.com/p/go.net/html/atom"
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"github.com/golang/glog"
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)
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type ProxyHandler struct {
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prefix string
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storage map[string]RESTStorage
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codec Codec
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}
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func (r *ProxyHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
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parts := strings.SplitN(req.URL.Path, "/", 3)
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if len(parts) < 2 {
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notFound(w, req)
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return
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}
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resourceName := parts[0]
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id := parts[1]
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rest := ""
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if len(parts) == 3 {
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rest = parts[2]
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}
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storage, ok := r.storage[resourceName]
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if !ok {
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httplog.LogOf(w).Addf("'%v' has no storage object", resourceName)
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notFound(w, req)
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return
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}
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redirector, ok := storage.(Redirector)
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if !ok {
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httplog.LogOf(w).Addf("'%v' is not a redirector", resourceName)
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notFound(w, req)
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return
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}
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location, err := redirector.ResourceLocation(id)
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if err != nil {
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status := errToAPIStatus(err)
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writeJSON(status.Code, r.codec, status, w)
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return
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}
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destURL, err := url.Parse(location)
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if err != nil {
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status := errToAPIStatus(err)
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writeJSON(status.Code, r.codec, status, w)
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return
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}
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destURL.Path = rest
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destURL.RawQuery = req.URL.RawQuery
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newReq, err := http.NewRequest(req.Method, destURL.String(), req.Body)
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if err != nil {
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glog.Errorf("Failed to create request: %s", err)
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}
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newReq.Header = req.Header
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proxy := httputil.NewSingleHostReverseProxy(&url.URL{Scheme: "http", Host: destURL.Host})
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proxy.Transport = &proxyTransport{
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proxyScheme: req.URL.Scheme,
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proxyHost: req.URL.Host,
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proxyPathPrepend: path.Join(r.prefix, resourceName, id),
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}
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proxy.ServeHTTP(w, newReq)
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}
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type proxyTransport struct {
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proxyScheme string
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proxyHost string
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proxyPathPrepend string
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}
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func (t *proxyTransport) RoundTrip(req *http.Request) (*http.Response, error) {
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resp, err := http.DefaultTransport.RoundTrip(req)
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if err != nil {
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message := err.Error() + "\n" + req.URL.String()
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if strings.Contains(err.Error(), "connection refused") {
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message = fmt.Sprintf("Failed to connect to %s (%s)", req.URL.Host, err)
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}
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resp = &http.Response{
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StatusCode: http.StatusServiceUnavailable,
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Body: ioutil.NopCloser(strings.NewReader(message)),
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}
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return resp, nil
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}
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if resp.Header.Get("Content-Type") != "text/html" {
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// Do nothing, simply pass through
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return resp, err
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}
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resp, err = t.fixLinks(req, resp)
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return resp, err
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}
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// fixLinks modifies links in an HTML file such that they will be redirected through the proxy if needed.
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func (t *proxyTransport) fixLinks(req *http.Request, resp *http.Response) (*http.Response, error) {
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body, err := ioutil.ReadAll(resp.Body)
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resp.Body.Close()
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if err != nil {
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// copying the response body did not work
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return nil, err
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}
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bodyNode := &html.Node{
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Type: html.ElementNode,
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Data: "body",
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DataAtom: atom.Body,
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}
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nodes, err := html.ParseFragment(bytes.NewBuffer(body), bodyNode)
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if err != nil {
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glog.Errorf("Failed to found <body> node: %v", err)
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return resp, err
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}
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// Define the method to traverse the doc tree and update href node to
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// point to correct minion
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var updateHRef func(*html.Node)
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updateHRef = func(n *html.Node) {
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if n.Type == html.ElementNode && n.Data == "a" {
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for i, attr := range n.Attr {
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if attr.Key == "href" {
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url, err := url.Parse(attr.Val)
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if err != nil {
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continue
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}
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url.Scheme = t.proxyScheme
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url.Host = t.proxyHost
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url.Path = path.Join(t.proxyPathPrepend, path.Dir(req.URL.Path), url.Path, "/")
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n.Attr[i].Val = url.String()
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break
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}
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}
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}
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for c := n.FirstChild; c != nil; c = c.NextSibling {
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updateHRef(c)
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}
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}
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newContent := &bytes.Buffer{}
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for _, n := range nodes {
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updateHRef(n)
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err = html.Render(newContent, n)
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if err != nil {
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glog.Errorf("Failed to render: %v", err)
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}
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}
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resp.Body = ioutil.NopCloser(newContent)
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// Update header node with new content-length
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// TODO: Remove any hash/signature headers here?
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resp.Header.Del("Content-Length")
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resp.ContentLength = int64(newContent.Len())
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return resp, err
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}
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