From 74920010d6bf81f33d1dfcb8443dbdca07ae7b88 Mon Sep 17 00:00:00 2001
From: Prem Saraswat <prmsrswt@gmail.com>
Date: Sun, 9 May 2021 15:07:19 +0530
Subject: [PATCH] UI: Fix infinite redirection loop on /

---
 pkg/ui/bucket.go | 7 ++-----
 pkg/ui/query.go  | 8 ++------
 pkg/ui/rule.go   | 9 ++-------
 pkg/ui/ui.go     | 1 +
 4 files changed, 7 insertions(+), 18 deletions(-)

diff --git a/pkg/ui/bucket.go b/pkg/ui/bucket.go
index 5a198a52af9..e9530c96fdf 100644
--- a/pkg/ui/bucket.go
+++ b/pkg/ui/bucket.go
@@ -62,11 +62,8 @@ func (b *Bucket) Register(r *route.Router, registerNewUI bool, ins extpromhttp.I
 		// Redirect the original React UI's path (under "/new") to its new path at the root.
 		r.Get("/new/*path", func(w http.ResponseWriter, r *http.Request) {
 			p := route.Param(r.Context(), "path")
-			http.Redirect(w, r, path.Join(GetWebPrefix(b.logger, b.externalPrefix, b.prefixHeader, r), strings.TrimPrefix(p, "/new"))+"?"+r.URL.RawQuery, http.StatusFound)
-		})
-
-		r.Get("/", func(w http.ResponseWriter, r *http.Request) {
-			http.Redirect(w, r, path.Join(GetWebPrefix(b.logger, b.externalPrefix, b.prefixHeader, r), b.uiPrefix), http.StatusFound)
+			prefix := GetWebPrefix(b.logger, b.externalPrefix, b.prefixHeader, r)
+			http.Redirect(w, r, path.Join("/", prefix, p)+"?"+r.URL.RawQuery, http.StatusFound)
 		})
 
 		registerReactApp(r, ins, b.BaseUI)
diff --git a/pkg/ui/query.go b/pkg/ui/query.go
index 260169a1900..7389dfbd548 100644
--- a/pkg/ui/query.go
+++ b/pkg/ui/query.go
@@ -67,18 +67,14 @@ func queryTmplFuncs() template.FuncMap {
 
 // Register registers new GET routes for subpages and redirects from / to /graph.
 func (q *Query) Register(r *route.Router, ins extpromhttp.InstrumentationMiddleware) {
-	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
-		http.Redirect(w, r, path.Join(GetWebPrefix(q.logger, q.externalPrefix, q.prefixHeader, r), "/graph"), http.StatusFound)
-	})
-
 	r.Get("/classic/", func(w http.ResponseWriter, r *http.Request) {
-		http.Redirect(w, r, path.Join(GetWebPrefix(q.logger, q.externalPrefix, q.prefixHeader, r), "/classic/graph"), http.StatusFound)
+		http.Redirect(w, r, path.Join("/", GetWebPrefix(q.logger, q.externalPrefix, q.prefixHeader, r), "/classic/graph"), http.StatusFound)
 	})
 
 	// Redirect the original React UI's path (under "/new") to its new path at the root.
 	r.Get("/new/*path", func(w http.ResponseWriter, r *http.Request) {
 		p := route.Param(r.Context(), "path")
-		http.Redirect(w, r, path.Join(GetWebPrefix(q.logger, q.externalPrefix, q.prefixHeader, r), strings.TrimPrefix(p, "/new"))+"?"+r.URL.RawQuery, http.StatusFound)
+		http.Redirect(w, r, path.Join("/", GetWebPrefix(q.logger, q.externalPrefix, q.prefixHeader, r), p)+"?"+r.URL.RawQuery, http.StatusFound)
 	})
 
 	r.Get("/classic/graph", instrf("graph", ins, q.graph))
diff --git a/pkg/ui/rule.go b/pkg/ui/rule.go
index 0a7eb2241d9..01869d2b63e 100644
--- a/pkg/ui/rule.go
+++ b/pkg/ui/rule.go
@@ -10,7 +10,6 @@ import (
 	"net/http"
 	"path"
 	"regexp"
-	"strings"
 	"time"
 
 	"github.com/go-kit/kit/log"
@@ -158,18 +157,14 @@ func (ru *Rule) rules(w http.ResponseWriter, r *http.Request) {
 }
 
 func (ru *Rule) Register(r *route.Router, ins extpromhttp.InstrumentationMiddleware) {
-	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
-		http.Redirect(w, r, path.Join(GetWebPrefix(ru.logger, ru.externalPrefix, ru.prefixHeader, r), "/alerts"), http.StatusFound)
-	})
-
 	r.Get("/classic/", func(w http.ResponseWriter, r *http.Request) {
-		http.Redirect(w, r, path.Join(GetWebPrefix(ru.logger, ru.externalPrefix, ru.prefixHeader, r), "/classic/alerts"), http.StatusFound)
+		http.Redirect(w, r, path.Join("/", GetWebPrefix(ru.logger, ru.externalPrefix, ru.prefixHeader, r), "/classic/alerts"), http.StatusFound)
 	})
 
 	// Redirect the original React UI's path (under "/new") to its new path at the root.
 	r.Get("/new/*path", func(w http.ResponseWriter, r *http.Request) {
 		p := route.Param(r.Context(), "path")
-		http.Redirect(w, r, path.Join(GetWebPrefix(ru.logger, ru.externalPrefix, ru.prefixHeader, r), strings.TrimPrefix(p, "/new"))+"?"+r.URL.RawQuery, http.StatusFound)
+		http.Redirect(w, r, path.Join("/", GetWebPrefix(ru.logger, ru.externalPrefix, ru.prefixHeader, r), p)+"?"+r.URL.RawQuery, http.StatusFound)
 	})
 
 	r.Get("/classic/alerts", instrf("alerts", ins, ru.alerts))
diff --git a/pkg/ui/ui.go b/pkg/ui/ui.go
index fbb6f9f6adf..d663c62b15f 100644
--- a/pkg/ui/ui.go
+++ b/pkg/ui/ui.go
@@ -23,6 +23,7 @@ import (
 )
 
 var reactRouterPaths = []string{
+	"/",
 	"/alerts",
 	"/blocks",
 	"/config",