Add a generic proxier

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.

pkg/apiserver/apiserver.go

@@ -99,8 +99,10 @@ func (g *APIGroup) InstallREST(mux mux, paths ...string) {
 
 	for _, prefix := range paths {
 		prefix = strings.TrimRight(prefix, "/")
+		proxyHandler := &ProxyHandler{prefix + "/proxy/", g.handler.storage, g.handler.codec}
 		mux.Handle(prefix+"/", http.StripPrefix(prefix, restHandler))
 		mux.Handle(prefix+"/watch/", http.StripPrefix(prefix+"/watch/", watchHandler))
+		mux.Handle(prefix+"/proxy/", http.StripPrefix(prefix+"/proxy/", proxyHandler))
 		mux.Handle(prefix+"/redirect/", http.StripPrefix(prefix+"/redirect/", redirectHandler))
 		mux.Handle(prefix+"/operations", http.StripPrefix(prefix+"/operations", opHandler))
 		mux.Handle(prefix+"/operations/", http.StripPrefix(prefix+"/operations/", opHandler))

pkg/apiserver/apiserver_test.go

@@ -73,8 +73,9 @@ type SimpleRESTStorage struct {
 	requestedFieldSelector   labels.Selector
 	requestedResourceVersion uint64
 
-	// The location
+	// The id requested, and location to return for ResourceLocation
 	requestedResourceLocationID string
+	resourceLocation            string
 
 	// If non-nil, called inside the WorkFunc when answering update, delete, create.
 	// obj receives the original input to the update, delete, or create call.
@@ -153,7 +154,7 @@ func (storage *SimpleRESTStorage) ResourceLocation(id string) (string, error) {
 	if err := storage.errors["resourceLocation"]; err != nil {
 		return "", err
 	}
-	return id, nil
+	return storage.resourceLocation, nil
 }
 
 func extractBody(response *http.Response, object interface{}) (string, error) {

pkg/apiserver/minionproxy.go

@@ -31,6 +31,7 @@ import (
 	"github.com/golang/glog"
 )
 
+// TODO: replace with proxy handler on minions
 func handleProxyMinion(w http.ResponseWriter, req *http.Request) {
 	path := strings.TrimLeft(req.URL.Path, "/")
 	rawQuery := req.URL.RawQuery

pkg/apiserver/proxy.go

@@ -0,0 +1,188 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"path"
+	"strings"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/httplog"
+
+	"code.google.com/p/go.net/html"
+	"code.google.com/p/go.net/html/atom"
+	"github.com/golang/glog"
+)
+
+type ProxyHandler struct {
+	prefix  string
+	storage map[string]RESTStorage
+	codec   Codec
+}
+
+func (r *ProxyHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	parts := strings.SplitN(req.URL.Path, "/", 3)
+	if len(parts) < 2 {
+		notFound(w, req)
+		return
+	}
+	resourceName := parts[0]
+	id := parts[1]
+	rest := ""
+	if len(parts) == 3 {
+		rest = parts[2]
+	}
+	storage, ok := r.storage[resourceName]
+	if !ok {
+		httplog.LogOf(w).Addf("'%v' has no storage object", resourceName)
+		notFound(w, req)
+		return
+	}
+
+	redirector, ok := storage.(Redirector)
+	if !ok {
+		httplog.LogOf(w).Addf("'%v' is not a redirector", resourceName)
+		notFound(w, req)
+		return
+	}
+
+	location, err := redirector.ResourceLocation(id)
+	if err != nil {
+		status := errToAPIStatus(err)
+		writeJSON(status.Code, r.codec, status, w)
+		return
+	}
+
+	destURL, err := url.Parse(location)
+	if err != nil {
+		status := errToAPIStatus(err)
+		writeJSON(status.Code, r.codec, status, w)
+		return
+	}
+	destURL.Path = rest
+	destURL.RawQuery = req.URL.RawQuery
+	newReq, err := http.NewRequest(req.Method, destURL.String(), req.Body)
+	if err != nil {
+		glog.Errorf("Failed to create request: %s", err)
+	}
+	newReq.Header = req.Header
+
+	proxy := httputil.NewSingleHostReverseProxy(&url.URL{Scheme: "http", Host: destURL.Host})
+	proxy.Transport = &proxyTransport{
+		proxyScheme:      req.URL.Scheme,
+		proxyHost:        req.URL.Host,
+		proxyPathPrepend: path.Join(r.prefix, resourceName, id),
+	}
+	proxy.ServeHTTP(w, newReq)
+}
+
+type proxyTransport struct {
+	proxyScheme      string
+	proxyHost        string
+	proxyPathPrepend string
+}
+
+func (t *proxyTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	resp, err := http.DefaultTransport.RoundTrip(req)
+
+	if err != nil {
+		message := err.Error() + "\n" + req.URL.String()
+		if strings.Contains(err.Error(), "connection refused") {
+			message = fmt.Sprintf("Failed to connect to %s (%s)", req.URL.Host, err)
+		}
+		resp = &http.Response{
+			StatusCode: http.StatusServiceUnavailable,
+			Body:       ioutil.NopCloser(strings.NewReader(message)),
+		}
+		return resp, nil
+	}
+
+	if resp.Header.Get("Content-Type") != "text/html" {
+		// Do nothing, simply pass through
+		return resp, err
+	}
+
+	resp, err = t.fixLinks(req, resp)
+	return resp, err
+}
+
+// fixLinks modifies links in an HTML file such that they will be redirected through the proxy if needed.
+func (t *proxyTransport) fixLinks(req *http.Request, resp *http.Response) (*http.Response, error) {
+	body, err := ioutil.ReadAll(resp.Body)
+	resp.Body.Close()
+	if err != nil {
+		// copying the response body did not work
+		return nil, err
+	}
+
+	bodyNode := &html.Node{
+		Type:     html.ElementNode,
+		Data:     "body",
+		DataAtom: atom.Body,
+	}
+	nodes, err := html.ParseFragment(bytes.NewBuffer(body), bodyNode)
+	if err != nil {
+		glog.Errorf("Failed to found <body> node: %v", err)
+		return resp, err
+	}
+
+	// Define the method to traverse the doc tree and update href node to
+	// point to correct minion
+	var updateHRef func(*html.Node)
+	updateHRef = func(n *html.Node) {
+		if n.Type == html.ElementNode && n.Data == "a" {
+			for i, attr := range n.Attr {
+				if attr.Key == "href" {
+					url, err := url.Parse(attr.Val)
+					if err != nil {
+						continue
+					}
+					url.Scheme = t.proxyScheme
+					url.Host = t.proxyHost
+					url.Path = path.Join(t.proxyPathPrepend, path.Dir(req.URL.Path), url.Path, "/")
+					n.Attr[i].Val = url.String()
+					break
+				}
+			}
+		}
+		for c := n.FirstChild; c != nil; c = c.NextSibling {
+			updateHRef(c)
+		}
+	}
+
+	newContent := &bytes.Buffer{}
+	for _, n := range nodes {
+		updateHRef(n)
+		err = html.Render(newContent, n)
+		if err != nil {
+			glog.Errorf("Failed to render: %v", err)
+		}
+	}
+
+	resp.Body = ioutil.NopCloser(newContent)
+	// Update header node with new content-length
+	// TODO: Remove any hash/signature headers here?
+	resp.Header.Del("Content-Length")
+	resp.ContentLength = int64(newContent.Len())
+
+	return resp, err
+}

pkg/apiserver/proxy_test.go

@@ -0,0 +1,137 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"testing"
+)
+
+func TestProxyTransport_fixLinks(t *testing.T) {
+	content := string(`<pre><a href="kubelet.log">kubelet.log</a><a href="/google.log">google.log</a></pre>`)
+	transport := &proxyTransport{
+		proxyScheme:      "http",
+		proxyHost:        "foo.com",
+		proxyPathPrepend: "/proxy/minion/minion1:10250/",
+	}
+
+	// Test /logs/
+	request := &http.Request{
+		Method: "GET",
+		URL: &url.URL{
+			Path: "/logs/",
+		},
+	}
+	response := &http.Response{
+		Status:     "200 OK",
+		StatusCode: http.StatusOK,
+		Body:       ioutil.NopCloser(strings.NewReader(content)),
+		Close:      true,
+	}
+	updated_resp, _ := transport.fixLinks(request, response)
+	body, _ := ioutil.ReadAll(updated_resp.Body)
+	expected := string(`<pre><a href="http://foo.com/proxy/minion/minion1:10250/logs/kubelet.log">kubelet.log</a><a href="http://foo.com/proxy/minion/minion1:10250/logs/google.log">google.log</a></pre>`)
+	if !strings.Contains(string(body), expected) {
+		t.Errorf("Received wrong content: %s", string(body))
+	}
+
+	// Test subdir under /logs/
+	request = &http.Request{
+		Method: "GET",
+		URL: &url.URL{
+			Path: "/whatever/apt/somelog.log",
+		},
+	}
+	transport.proxyScheme = "https"
+	transport.proxyPathPrepend = "/proxy/minion/minion1:8080/"
+	response = &http.Response{
+		Status:     "200 OK",
+		StatusCode: http.StatusOK,
+		Body:       ioutil.NopCloser(strings.NewReader(content)),
+		Close:      true,
+	}
+	updated_resp, _ = transport.fixLinks(request, response)
+	body, _ = ioutil.ReadAll(updated_resp.Body)
+	expected = string(`<pre><a href="https://foo.com/proxy/minion/minion1:8080/whatever/apt/kubelet.log">kubelet.log</a><a href="https://foo.com/proxy/minion/minion1:8080/whatever/apt/google.log">google.log</a></pre>`)
+	if !strings.Contains(string(body), expected) {
+		t.Errorf("Received wrong content: %s", string(body))
+	}
+}
+
+func TestProxy(t *testing.T) {
+	table := []struct {
+		method   string
+		path     string
+		reqBody  string
+		respBody string
+	}{
+		{"GET", "/some/dir", "", "answer"},
+		{"POST", "/some/other/dir", "question", "answer"},
+		{"PUT", "/some/dir/id", "different question", "answer"},
+		{"DELETE", "/some/dir/id", "", "ok"},
+	}
+
+	for _, item := range table {
+		proxyServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+			gotBody, err := ioutil.ReadAll(req.Body)
+			if err != nil {
+				t.Errorf("%v - unexpected error %v", item.method, err)
+			}
+			if e, a := item.reqBody, string(gotBody); e != a {
+				t.Errorf("%v - expected %v, got %v", item.method, e, a)
+			}
+			fmt.Fprint(w, item.respBody)
+		}))
+
+		simpleStorage := &SimpleRESTStorage{
+			errors:           map[string]error{},
+			resourceLocation: proxyServer.URL,
+		}
+		handler := Handle(map[string]RESTStorage{
+			"foo": simpleStorage,
+		}, codec, "/prefix/version")
+		server := httptest.NewServer(handler)
+
+		req, err := http.NewRequest(
+			item.method,
+			server.URL+"/prefix/version/proxy/foo/id"+item.path,
+			strings.NewReader(item.reqBody),
+		)
+		if err != nil {
+			t.Errorf("%v - unexpected error %v", item.method, err)
+			continue
+		}
+		resp, err := http.DefaultClient.Do(req)
+		if err != nil {
+			t.Errorf("%v - unexpected error %v", item.method, err)
+			continue
+		}
+		gotResp, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			t.Errorf("%v - unexpected error %v", item.method, err)
+		}
+		resp.Body.Close()
+		if e, a := item.respBody, string(gotResp); e != a {
+			t.Errorf("%v - expected %v, got %v", item.method, e, a)
+		}
+	}
+}

pkg/apiserver/redirect_test.go

@@ -51,6 +51,7 @@ func TestRedirect(t *testing.T) {
 
 	for _, item := range table {
 		simpleStorage.errors["resourceLocation"] = item.err
+		simpleStorage.resourceLocation = item.id
 		resp, err := client.Get(server.URL + "/prefix/version/redirect/foo/" + item.id)
 		if resp == nil {
 			t.Fatalf("Unexpected nil resp")

pkg/registry/service/storage.go

@@ -179,7 +179,7 @@ func (rs *RegistryStorage) ResourceLocation(id string) (string, error) {
 	if len(e.Endpoints) == 0 {
 		return "", fmt.Errorf("no endpoints available for %v", id)
 	}
-	return e.Endpoints[rand.Intn(len(e.Endpoints))], nil
+	return "http://" + e.Endpoints[rand.Intn(len(e.Endpoints))], nil
 }
 
 func (rs *RegistryStorage) deleteExternalLoadBalancer(service *api.Service) error {

pkg/registry/service/storage_test.go

@@ -291,7 +291,7 @@ func TestServiceRegistryResourceLocation(t *testing.T) {
 	if err != nil {
 		t.Errorf("Unexpected error: %v", err)
 	}
-	if e, a := "foo:80", location; e != a {
+	if e, a := "http://foo:80", location; e != a {
 		t.Errorf("Expected %v, but got %v", e, a)
 	}
 	if e, a := "foo", registry.GottenID; e != a {