From 695b08885bdc63f574b0ec0c2279a381856ff8c9 Mon Sep 17 00:00:00 2001
From: Anthony Yeh <enisoc@google.com>
Date: Mon, 2 Feb 2015 13:01:46 -0800
Subject: [PATCH] Fix apiserver proxy path rewriting.

1) Absolute paths without a hostname were being rewritten relative to
   the current page, rather than relative to the current host.
   e.g. When viewing /some/page.html, it would rewrite:
       /other/page.html => proxyPrepend/some/other/page.html
   Instead, it should rewrite:
       /other/page.html => proxyPrepend/other/page.html

2) Trailing slashes were being stripped from all rewritten URLs.
   This is because path.Join() always calls path.Clean() as well:
   http://golang.org/pkg/path/#Join
---
 pkg/apiserver/proxy.go      | 26 ++++++++++++++++++--------
 pkg/apiserver/proxy_test.go | 14 +++++++++++---
 2 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/pkg/apiserver/proxy.go b/pkg/apiserver/proxy.go
index 360ef417152..d42e9fc87c0 100644
--- a/pkg/apiserver/proxy.go
+++ b/pkg/apiserver/proxy.go
@@ -216,16 +216,26 @@ func (t *proxyTransport) updateURLs(n *html.Node, sourceURL *url.URL) {
 		if err != nil {
 			continue
 		}
-		// Is this URL relative?
-		if url.Host == "" {
+
+		// Is this URL referring to the same host as sourceURL?
+		if url.Host == "" || url.Host == sourceURL.Host {
 			url.Scheme = t.proxyScheme
 			url.Host = t.proxyHost
-			url.Path = path.Join(t.proxyPathPrepend, path.Dir(sourceURL.Path), url.Path, "/")
-			n.Attr[i].Val = url.String()
-		} else if url.Host == sourceURL.Host {
-			url.Scheme = t.proxyScheme
-			url.Host = t.proxyHost
-			url.Path = path.Join(t.proxyPathPrepend, url.Path)
+			origPath := url.Path
+
+			if strings.HasPrefix(url.Path, "/") {
+				// The path is rooted at the host. Just add proxy prepend.
+				url.Path = path.Join(t.proxyPathPrepend, url.Path)
+			} else {
+				// The path is relative to sourceURL.
+				url.Path = path.Join(t.proxyPathPrepend, path.Dir(sourceURL.Path), url.Path)
+			}
+
+			if strings.HasSuffix(origPath, "/") {
+				// Add back the trailing slash, which was stripped by path.Join().
+				url.Path += "/"
+			}
+
 			n.Attr[i].Val = url.String()
 		}
 	}
diff --git a/pkg/apiserver/proxy_test.go b/pkg/apiserver/proxy_test.go
index 8eb51e4d09a..0113f86e8c5 100644
--- a/pkg/apiserver/proxy_test.go
+++ b/pkg/apiserver/proxy_test.go
@@ -76,7 +76,15 @@ func TestProxyTransport(t *testing.T) {
 			input:        `<pre><a href="kubelet.log">kubelet.log</a><a href="/google.log">google.log</a></pre>`,
 			sourceURL:    "http://myminion.com/logs/log.log",
 			transport:    testTransport,
-			output:       `<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>`,
+			output:       `<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/google.log">google.log</a></pre>`,
+			contentType:  "text/html",
+			forwardedURI: "/proxy/minion/minion1:10250/logs/log.log",
+		},
+		"trailing slash": {
+			input:        `<pre><a href="kubelet.log">kubelet.log</a><a href="/google.log/">google.log</a></pre>`,
+			sourceURL:    "http://myminion.com/logs/log.log",
+			transport:    testTransport,
+			output:       `<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/google.log/">google.log</a></pre>`,
 			contentType:  "text/html",
 			forwardedURI: "/proxy/minion/minion1:10250/logs/log.log",
 		},
@@ -84,7 +92,7 @@ func TestProxyTransport(t *testing.T) {
 			input:        `<pre><a href="kubelet.log">kubelet.log</a><a href="/google.log">google.log</a></pre>`,
 			sourceURL:    "http://myminion.com/logs/log.log",
 			transport:    testTransport,
-			output:       `<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>`,
+			output:       `<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/google.log">google.log</a></pre>`,
 			contentType:  "text/html; charset=utf-8",
 			forwardedURI: "/proxy/minion/minion1:10250/logs/log.log",
 		},
@@ -100,7 +108,7 @@ func TestProxyTransport(t *testing.T) {
 			input:        `<a href="kubelet.log">kubelet.log</a><a href="/google.log">google.log</a>`,
 			sourceURL:    "http://myminion.com/whatever/apt/somelog.log",
 			transport:    testTransport2,
-			output:       `<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>`,
+			output:       `<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/google.log">google.log</a>`,
 			contentType:  "text/html",
 			forwardedURI: "/proxy/minion/minion1:8080/whatever/apt/somelog.log",
 		},