From 89fee056d36328fdb4de84a9a87189ed52b44e35 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Fri, 9 Sep 2022 10:21:39 -0700
Subject: [PATCH] cmd/derper: add robots.txt to disallow all

Fixes #5565

Change-Id: I5626ec2116d9be451caef651dc301b7a82e35550
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
---
 cmd/derper/derper.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/cmd/derper/derper.go b/cmd/derper/derper.go
index c397d4ffa..653c6d9be 100644
--- a/cmd/derper/derper.go
+++ b/cmd/derper/derper.go
@@ -203,6 +203,9 @@ func main() {
 			io.WriteString(w, "<p>Debug info at <a href='/debug/'>/debug/</a>.</p>\n")
 		}
 	}))
+	mux.Handle("/robots.txt", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		io.WriteString(w, "User-agent: *\nDisallow: /\n")
+	}))
 	debug := tsweb.Debugger(mux)
 	debug.KV("TLS hostname", *hostname)
 	debug.KV("Mesh key", s.HasMeshKey())