introduce reader deadlines for net.Conn (#19023)

Bonus: set "retry-after" header for AWS SDKs if possible to honor them.

internal/http/listener.go

@@ -22,6 +22,9 @@ import (
 	"fmt"
 	"net"
 	"syscall"
+	"time"
+
+	"github.com/minio/minio/internal/deadlineconn"
 )
 
 type acceptResult struct {
@@ -32,6 +35,7 @@ type acceptResult struct {
 
 // httpListener - HTTP listener capable of handling multiple server addresses.
 type httpListener struct {
+	opts         TCPOptions
 	tcpListeners []*net.TCPListener // underlying TCP listeners.
 	acceptCh     chan acceptResult  // channel where all TCP listeners write accepted connection.
 	ctx          context.Context
@@ -74,7 +78,8 @@ func (listener *httpListener) Accept() (conn net.Conn, err error) {
 	select {
 	case result, ok := <-listener.acceptCh:
 		if ok {
-			return result.conn, result.err
+			return deadlineconn.New(result.conn).
+				WithReadDeadline(listener.opts.ClientReadTimeout), result.err
 		}
 	case <-listener.ctx.Done():
 	}
@@ -119,9 +124,10 @@ func (listener *httpListener) Addrs() (addrs []net.Addr) {
 
 // TCPOptions specify customizable TCP optimizations on raw socket
 type TCPOptions struct {
-	UserTimeout int              // this value is expected to be in milliseconds
-	Interface   string           // this is a VRF device passed via `--interface` flag
-	Trace       func(msg string) // Trace when starting.
+	UserTimeout       int              // this value is expected to be in milliseconds
+	ClientReadTimeout time.Duration    // When the net.Conn is idle for more than ReadTimeout duration, we close the connection on the client proactively.
+	Interface         string           // this is a VRF device passed via `--interface` flag
+	Trace             func(msg string) // Trace when starting.
 }
 
 // newHTTPListener - creates new httpListener object which is interface compatible to net.Listener.
@@ -173,6 +179,7 @@ func newHTTPListener(ctx context.Context, serverAddrs []string, opts TCPOptions)
 	listener = &httpListener{
 		tcpListeners: tcpListeners,
 		acceptCh:     make(chan acceptResult, len(tcpListeners)),
+		opts:         opts,
 	}
 	listener.ctx, listener.ctxCanceler = context.WithCancel(ctx)
 	if opts.Trace != nil {

internal/http/server.go

@@ -109,8 +109,12 @@ func (srv *Server) Init(listenCtx context.Context, listenErrCallback func(listen
 	wrappedHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		// If server is in shutdown.
 		if atomic.LoadUint32(&srv.inShutdown) != 0 {
-			// To indicate disable keep-alive
+			// To indicate disable keep-alive, server is shutting down.
 			w.Header().Set("Connection", "close")
+
+			// Add 1 minute retry header, incase-client wants to honor it
+			w.Header().Set(RetryAfter, "60")
+
 			w.WriteHeader(http.StatusServiceUnavailable)
 			w.Write([]byte(http.ErrServerClosed.Error()))
 			return