From 36b622bfc2832652bab668255be1beae735954f8 Mon Sep 17 00:00:00 2001
From: Mariano Cano <mariano.cano@gmail.com>
Date: Fri, 15 Oct 2021 14:12:43 -0700
Subject: [PATCH] Use Golang's default keep-alive.

Since Go 1.13 a net.Listen keep-alive is enabled by default if
the protocol and OS supports it. The new one is 15s to match
the net.Dial default one. Previously http.Server ListenAndServe
and ListenAndServeTLS used to add a wrapper with 3m that we
replicated.

See https://github.com/golang/go/issues/31510
---
 ca/tls.go                       |  4 ++--
 examples/basic-client/client.go |  1 -
 server/server.go                | 22 ++--------------------
 3 files changed, 4 insertions(+), 23 deletions(-)

diff --git a/ca/tls.go b/ca/tls.go
index 3a3b6766..0738d0e0 100644
--- a/ca/tls.go
+++ b/ca/tls.go
@@ -279,9 +279,9 @@ func getDefaultTLSConfig(sign *api.SignResponse) *tls.Config {
 
 // getDefaultDialer returns a new dialer with the default configuration.
 func getDefaultDialer() *net.Dialer {
+	// With the KeepAlive parameter set to 0, it will be use Golang's default.
 	return &net.Dialer{
-		Timeout:   30 * time.Second,
-		KeepAlive: 30 * time.Second,
+		Timeout: 30 * time.Second,
 	}
 }
 
diff --git a/examples/basic-client/client.go b/examples/basic-client/client.go
index db6092bf..42358ac8 100644
--- a/examples/basic-client/client.go
+++ b/examples/basic-client/client.go
@@ -116,7 +116,6 @@ func main() {
 			Proxy: http.ProxyFromEnvironment,
 			DialContext: (&net.Dialer{
 				Timeout:   30 * time.Second,
-				KeepAlive: 30 * time.Second,
 				DualStack: true,
 			}).DialContext,
 			MaxIdleConns:          100,
diff --git a/server/server.go b/server/server.go
index d3968c4a..2b864148 100644
--- a/server/server.go
+++ b/server/server.go
@@ -72,10 +72,10 @@ func (srv *Server) Serve(ln net.Listener) error {
 		// Start server
 		if srv.TLSConfig == nil || (len(srv.TLSConfig.Certificates) == 0 && srv.TLSConfig.GetCertificate == nil) {
 			log.Printf("Serving HTTP on %s ...", srv.Addr)
-			err = srv.Server.Serve(tcpKeepAliveListener{ln.(*net.TCPListener)})
+			err = srv.Server.Serve(ln)
 		} else {
 			log.Printf("Serving HTTPS on %s ...", srv.Addr)
-			err = srv.Server.ServeTLS(tcpKeepAliveListener{ln.(*net.TCPListener)}, "", "")
+			err = srv.Server.ServeTLS(ln, "", "")
 		}
 
 		// log unexpected errors
@@ -155,21 +155,3 @@ func (srv *Server) Forbidden(w http.ResponseWriter) {
 	w.WriteHeader(http.StatusForbidden)
 	w.Write([]byte("Forbidden.\n"))
 }
-
-// tcpKeepAliveListener sets TCP keep-alive timeouts on accepted
-// connections. It's used by ListenAndServe and ListenAndServeTLS so
-// dead TCP connections (e.g. closing laptop mid-download) eventually
-// go away.
-type tcpKeepAliveListener struct {
-	*net.TCPListener
-}
-
-func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) {
-	tc, err := ln.AcceptTCP()
-	if err != nil {
-		return
-	}
-	tc.SetKeepAlive(true)
-	tc.SetKeepAlivePeriod(3 * time.Minute)
-	return tc, nil
-}