From f4ac81b710e8622ca8dc58f1296c180e780924fb Mon Sep 17 00:00:00 2001
From: Daniel Jiang <jiangd@vmware.com>
Date: Fri, 28 May 2021 16:13:20 +0800
Subject: [PATCH] Add merge slash middleware

There are code in the core component to conditionally execute code based
on the pattern of url path, and different ingress controller or reverse
proxy may handle the dup slashes in the url path differently.
This commit merge dup slashes in the url paths to make things more
consistent.

Signed-off-by: Daniel Jiang <jiangd@vmware.com>
---
 src/core/middlewares/middlewares.go           |  2 +
 .../middleware/mergeslash/mergeslash.go       | 19 +++++++
 .../middleware/mergeslash/mergeslash_test.go  | 52 +++++++++++++++++++
 3 files changed, 73 insertions(+)
 create mode 100644 src/server/middleware/mergeslash/mergeslash.go
 create mode 100644 src/server/middleware/mergeslash/mergeslash_test.go

diff --git a/src/core/middlewares/middlewares.go b/src/core/middlewares/middlewares.go
index ce2ea5981..84efc9942 100644
--- a/src/core/middlewares/middlewares.go
+++ b/src/core/middlewares/middlewares.go
@@ -24,6 +24,7 @@ import (
 	"github.com/goharbor/harbor/src/server/middleware/artifactinfo"
 	"github.com/goharbor/harbor/src/server/middleware/csrf"
 	"github.com/goharbor/harbor/src/server/middleware/log"
+	"github.com/goharbor/harbor/src/server/middleware/mergeslash"
 	"github.com/goharbor/harbor/src/server/middleware/metric"
 	"github.com/goharbor/harbor/src/server/middleware/notification"
 	"github.com/goharbor/harbor/src/server/middleware/orm"
@@ -77,6 +78,7 @@ var (
 // MiddleWares returns global middlewares
 func MiddleWares() []beego.MiddleWare {
 	return []beego.MiddleWare{
+		mergeslash.Middleware(),
 		metric.Middleware(),
 		requestid.Middleware(),
 		log.Middleware(),
diff --git a/src/server/middleware/mergeslash/mergeslash.go b/src/server/middleware/mergeslash/mergeslash.go
new file mode 100644
index 000000000..622546808
--- /dev/null
+++ b/src/server/middleware/mergeslash/mergeslash.go
@@ -0,0 +1,19 @@
+package mergeslash
+
+import (
+	"net/http"
+	"regexp"
+
+	"github.com/goharbor/harbor/src/server/middleware"
+)
+
+var multiSlash = regexp.MustCompile(`(/+)`)
+
+// Middleware creates the middleware to merge slashes in the URL path of the request
+func Middleware(skippers ...middleware.Skipper) func(http.Handler) http.Handler {
+	return middleware.New(func(w http.ResponseWriter, r *http.Request, next http.Handler) {
+		path := multiSlash.ReplaceAll([]byte(r.URL.Path), []byte("/"))
+		r.URL.Path = string(path)
+		next.ServeHTTP(w, r)
+	}, skippers...)
+}
diff --git a/src/server/middleware/mergeslash/mergeslash_test.go b/src/server/middleware/mergeslash/mergeslash_test.go
new file mode 100644
index 000000000..9397ccff2
--- /dev/null
+++ b/src/server/middleware/mergeslash/mergeslash_test.go
@@ -0,0 +1,52 @@
+package mergeslash
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type handler struct {
+	path string
+}
+
+func (h *handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	h.path = req.URL.Path
+	w.WriteHeader(200)
+}
+
+func TestMergeSlash(t *testing.T) {
+	next := &handler{}
+	rec := httptest.NewRecorder()
+	req1, _ := http.NewRequest(http.MethodGet, "https://test.local/api/v2.0/systeminfo/", nil)
+	req2, _ := http.NewRequest(http.MethodGet, "https://test.local/v2//////_catalog", nil)
+	req3, _ := http.NewRequest(http.MethodPost, "https://test.local/v2/library///////ubuntu//blobs/uploads///////", nil)
+	req4, _ := http.NewRequest(http.MethodGet, "https://test.local//api/v2.0///////artifacts?scan_overview=false", nil)
+	cases := []struct {
+		req          *http.Request
+		expectedPath string
+	}{
+		{
+			req:          req1,
+			expectedPath: "/api/v2.0/systeminfo/",
+		},
+		{
+			req:          req2,
+			expectedPath: "/v2/_catalog",
+		},
+		{
+			req:          req3,
+			expectedPath: "/v2/library/ubuntu/blobs/uploads/",
+		},
+		{
+			req:          req4,
+			expectedPath: "/api/v2.0/artifacts",
+		},
+	}
+	for _, tt := range cases {
+		Middleware()(next).ServeHTTP(rec, tt.req)
+		assert.Equal(t, tt.expectedPath, next.path)
+	}
+}