Rewrite "Location" header in apiserver proxy.

So that redirects work correctly.

pkg/apiserver/proxy_test.go

@@ -63,15 +63,18 @@ func TestProxyTransport(t *testing.T) {
 		proxyHost:        "foo.com",
 		proxyPathPrepend: "/proxy/minion/minion1:8080",
 	}
-
-	table := map[string]struct {
+	type Item struct {
 		input        string
 		sourceURL    string
 		transport    *proxyTransport
 		output       string
 		contentType  string
 		forwardedURI string
-	}{
+		redirect     string
+		redirectWant string
+	}
+
+	table := map[string]Item{
 		"normal": {
 			input:        `<pre><a href="kubelet.log">kubelet.log</a><a href="/google.log">google.log</a></pre>`,
 			sourceURL:    "http://myminion.com/logs/log.log",
@@ -136,9 +139,30 @@ func TestProxyTransport(t *testing.T) {
 			contentType:  "text/html",
 			forwardedURI: "/proxy/minion/minion1:10250/any/path/",
 		},
+		"redirect rel": {
+			sourceURL:    "http://myminion.com/redirect",
+			transport:    testTransport,
+			redirect:     "/redirected/target/",
+			redirectWant: "http://foo.com/proxy/minion/minion1:10250/redirected/target/",
+			forwardedURI: "/proxy/minion/minion1:10250/redirect",
+		},
+		"redirect abs same host": {
+			sourceURL:    "http://myminion.com/redirect",
+			transport:    testTransport,
+			redirect:     "http://myminion.com/redirected/target/",
+			redirectWant: "http://foo.com/proxy/minion/minion1:10250/redirected/target/",
+			forwardedURI: "/proxy/minion/minion1:10250/redirect",
+		},
+		"redirect abs other host": {
+			sourceURL:    "http://myminion.com/redirect",
+			transport:    testTransport,
+			redirect:     "http://example.com/redirected/target/",
+			redirectWant: "http://example.com/redirected/target/",
+			forwardedURI: "/proxy/minion/minion1:10250/redirect",
+		},
 	}
 
-	for name, item := range table {
+	testItem := func(name string, item *Item) {
 		// Canonicalize the html so we can diff.
 		item.input = fmtHTML(item.input)
 		item.output = fmtHTML(item.output)
@@ -156,34 +180,51 @@ func TestProxyTransport(t *testing.T) {
 			}
 
 			// Send response.
+			if item.redirect != "" {
+				http.Redirect(w, r, item.redirect, http.StatusMovedPermanently)
+				return
+			}
 			w.Header().Set("Content-Type", item.contentType)
 			fmt.Fprint(w, item.input)
 		}))
+		defer server.Close()
+
 		// Replace source URL with our test server address.
 		sourceURL := parseURLOrDie(item.sourceURL)
 		serverURL := parseURLOrDie(server.URL)
 		item.input = strings.Replace(item.input, sourceURL.Host, serverURL.Host, -1)
+		item.redirect = strings.Replace(item.redirect, sourceURL.Host, serverURL.Host, -1)
 		sourceURL.Host = serverURL.Host
 
 		req, err := http.NewRequest("GET", sourceURL.String(), nil)
 		if err != nil {
 			t.Errorf("%v: Unexpected error: %v", name, err)
-			continue
+			return
 		}
 		resp, err := item.transport.RoundTrip(req)
 		if err != nil {
 			t.Errorf("%v: Unexpected error: %v", name, err)
-			continue
+			return
+		}
+		if item.redirect != "" {
+			// Check that redirect URLs get rewritten properly.
+			if got, want := resp.Header.Get("Location"), item.redirectWant; got != want {
+				t.Errorf("%v: Location header = %q, want %q", name, got, want)
+			}
+			return
 		}
 		body, err := ioutil.ReadAll(resp.Body)
 		if err != nil {
 			t.Errorf("%v: Unexpected error: %v", name, err)
-			continue
+			return
 		}
 		if e, a := item.output, string(body); e != a {
 			t.Errorf("%v: expected %v, but got %v", name, e, a)
 		}
-		server.Close()
+	}
+
+	for name, item := range table {
+		testItem(name, &item)
 	}
 }