Use X-Forwarded-{Proto,Host,Uri} on redirect as last resort (#957)

pkg/util/util.go

@@ -25,6 +25,15 @@ func GetCertPool(paths []string) (*x509.CertPool, error) {
 	return pool, nil
 }
 
+// GetRequestProto return the request host header or X-Forwarded-Proto if present
+func GetRequestProto(req *http.Request) string {
+	proto := req.Header.Get("X-Forwarded-Proto")
+	if proto == "" {
+		proto = req.URL.Scheme
+	}
+	return proto
+}
+
 // GetRequestHost return the request host header or X-Forwarded-Host if present
 func GetRequestHost(req *http.Request) string {
 	host := req.Header.Get("X-Forwarded-Host")
@@ -33,3 +42,13 @@ func GetRequestHost(req *http.Request) string {
 	}
 	return host
 }
+
+// GetRequestURI return the request host header or X-Forwarded-Uri if present
+func GetRequestURI(req *http.Request) string {
+	uri := req.Header.Get("X-Forwarded-Uri")
+	if uri == "" {
+		// Use RequestURI to preserve ?query
+		uri = req.URL.RequestURI()
+	}
+	return uri
+}

pkg/util/util_test.go

@@ -110,3 +110,29 @@ func TestGetRequestHost(t *testing.T) {
 	extHost := GetRequestHost(proxyReq)
 	g.Expect(extHost).To(Equal("external.example.com"))
 }
+
+func TestGetRequestProto(t *testing.T) {
+	g := NewWithT(t)
+
+	req := httptest.NewRequest("GET", "https://example.com", nil)
+	proto := GetRequestProto(req)
+	g.Expect(proto).To(Equal("https"))
+
+	proxyReq := httptest.NewRequest("GET", "https://internal.example.com", nil)
+	proxyReq.Header.Add("X-Forwarded-Proto", "http")
+	extProto := GetRequestProto(proxyReq)
+	g.Expect(extProto).To(Equal("http"))
+}
+
+func TestGetRequestURI(t *testing.T) {
+	g := NewWithT(t)
+
+	req := httptest.NewRequest("GET", "https://example.com/ping", nil)
+	uri := GetRequestURI(req)
+	g.Expect(uri).To(Equal("/ping"))
+
+	proxyReq := httptest.NewRequest("GET", "http://internal.example.com/bong", nil)
+	proxyReq.Header.Add("X-Forwarded-Uri", "/ping")
+	extURI := GetRequestURI(proxyReq)
+	g.Expect(extURI).To(Equal("/ping"))
+}