From b86e31b92713e9ac752b080bec4b8b350bf17b7c Mon Sep 17 00:00:00 2001
From: Phil Porada <pporada@letsencrypt.org>
Date: Fri, 22 May 2026 13:07:01 -0700
Subject: [PATCH] Allow changing the HTML page title via config

---
 cmd/sunlight/home.html   |  2 +-
 cmd/sunlight/sunlight.go | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/cmd/sunlight/home.html b/cmd/sunlight/home.html
index 43e7f38..e531f91 100644
--- a/cmd/sunlight/home.html
+++ b/cmd/sunlight/home.html
@@ -5,7 +5,7 @@
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-    <title>Sunlight</title>
+    <title>{{ .Title }}</title>
 
     <link rel="preconnect" href="https://fonts.googleapis.com">
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
diff --git a/cmd/sunlight/sunlight.go b/cmd/sunlight/sunlight.go
index 4c903c9..42bc8ef 100644
--- a/cmd/sunlight/sunlight.go
+++ b/cmd/sunlight/sunlight.go
@@ -65,6 +65,10 @@ import (
 )
 
 type Config struct {
+	// Name is the display name for this Sunlight instance, used as the
+	// HTML page title. Optional. If empty, the title defaults to "Sunlight".
+	Name string
+
 	// Listen are the addresses to listen on, e.g. ":443".
 	Listen []string
 
@@ -466,10 +470,16 @@ func main() {
 	homeWitnessInfo := func() witnessInfo { return witnessInfo{} }
 	mux.HandleFunc("/{$}", func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "text/html")
+		pageTitle := "Sunlight"
+		if c.Name != "" {
+			pageTitle = c.Name
+		}
 		if err := homeTmpl.Execute(w, struct {
+			Title   string
 			Logs    []logInfo
 			Witness witnessInfo
 		}{
+			Title:   pageTitle,
 			Logs:    homeLogsInfo(),
 			Witness: homeWitnessInfo(),
 		}); err != nil {