fixing sub path_mode

src/go-proxy/utils.go

@@ -6,10 +6,14 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"path"
+	"path/filepath"
+	"regexp"
 	"strings"
 	"sync"
 	"time"
 
+	"github.com/golang/glog"
 	xhtml "golang.org/x/net/html"
 )
 
@@ -79,7 +83,7 @@ func (*Utils) healthCheckHttp(targetUrl string) error {
 	return err
 }
 
-func (*Utils) healthCheckStream(scheme string, host string) error {
+func (*Utils) healthCheckStream(scheme, host string) error {
 	conn, err := net.DialTimeout(scheme, host, 5*time.Second)
 	if err != nil {
 		return err
@@ -93,25 +97,49 @@ func (*Utils) snakeToCamel(s string) string {
 	return strings.ReplaceAll(toHyphenCamel, "-", "")
 }
 
-func htmlNodesSubPath(node *xhtml.Node, path string) {
-	if node.Type == xhtml.ElementNode {
-		for _, attr := range node.Attr {
-			switch attr.Key {
-			case "src": // img, script, etc.
-			case "href": // link
-			case "action": // form
-				if strings.HasPrefix(attr.Val, path) {
-					attr.Val = strings.Replace(attr.Val, path, "", 1)
-				}
-			}
-		}
-	}
-	for c := node.FirstChild; c != nil; c = c.NextSibling {
-		htmlNodesSubPath(c, path)
+func tryAppendPathPrefixImpl(pOrig, pAppend string) string {
+	switch {
+	case strings.Contains(pOrig, "://"):
+		return pOrig
+	case pOrig == "", pOrig == "#", pOrig == "/":
+		return pAppend
+	case filepath.IsLocal(pOrig) && !strings.HasPrefix(pOrig, pAppend):
+		return path.Join(pAppend, pOrig)
+	default:
+		return pOrig
 	}
 }
 
-func (*Utils) respRemovePath(r *http.Response, path string) error {
+var tryAppendPathPrefix func(string, string) string
+var _ = func() int {
+	if glog.V(4) {
+		tryAppendPathPrefix = func(s1, s2 string) string {
+			replaced := tryAppendPathPrefixImpl(s1, s2)
+			glog.Infof("[Path sub] %s -> %s", s1, replaced)
+			return replaced
+		}
+	} else {
+		tryAppendPathPrefix = tryAppendPathPrefixImpl
+	}
+	return 1
+}()
+
+func htmlNodesSubPath(n *xhtml.Node, p string) {
+	if n.Type == xhtml.ElementNode {
+		for i, attr := range n.Attr {
+			switch attr.Key {
+			case "src", "href", "action": // img, script, link, form etc.
+				n.Attr[i].Val = tryAppendPathPrefix(attr.Val, p)
+			}
+		}
+	}
+
+	for c := n.FirstChild; c != nil; c = c.NextSibling {
+		htmlNodesSubPath(c, p)
+	}
+}
+
+func (*Utils) respHTMLSubPath(r *http.Response, p string) error {
 	// remove all path prefix from relative path in script, img, a, ...
 	doc, err := xhtml.Parse(r.Body)
 
@@ -119,11 +147,14 @@ func (*Utils) respRemovePath(r *http.Response, path string) error {
 		return err
 	}
 
-	htmlNodesSubPath(doc, path)
+	if p[0] == '/' {
+		p = p[1:]
+	}
+	htmlNodesSubPath(doc, p)
 
 	var buf bytes.Buffer
 	err = xhtml.Render(&buf, doc)
-	
+
 	if err != nil {
 		return err
 	}
@@ -132,3 +163,29 @@ func (*Utils) respRemovePath(r *http.Response, path string) error {
 
 	return nil
 }
+
+func (*Utils) respJSSubPath(r *http.Response, p string) error {
+	var buf bytes.Buffer
+
+	_, err := buf.ReadFrom(r.Body)
+	if err != nil {
+		return err
+	}
+
+	if p[0] == '/' {
+		p = p[1:]
+	}
+
+	js := buf.String()
+
+	re := regexp.MustCompile(`fetch\(["'].+["']\)`)
+	replace := func(match string) string {
+		match = match[7 : len(match)-2]
+		replaced := tryAppendPathPrefix(match, p)
+		return fmt.Sprintf(`fetch(%q)`, replaced)
+	}
+	js = re.ReplaceAllStringFunc(js, replace)
+
+	r.Body = io.NopCloser(strings.NewReader(js))
+	return nil
+}