Remove PauseAccept of the reverse proxy from the e2e test

Part of the patches to fix https://github.com/etcd-io/etcd/issues/17737

During the development of https://github.com/etcd-io/etcd/pull/17938,
we agreed that during the transition to L7 forward proxy, unused
features and features targeting L4 reverse proxy will be dropped.

This feature falls under the unused feature.

Signed-off-by: Chun-Hung Tseng <henrybear327@gmail.com>

pkg/proxy/server.go

@@ -59,11 +59,6 @@ type Server interface {
 	// Close closes listener and transport.
 	Close() error
 
-	// PauseAccept stops accepting new connections.
-	PauseAccept()
-	// UnpauseAccept removes pause operation on accepting new connections.
-	UnpauseAccept()
-
 	// DelayAccept adds latency ± random variable to accepting
 	// new incoming connections.
 	DelayAccept(latency, rv time.Duration)
@@ -115,16 +110,6 @@ type Server interface {
 	// UnblackholeRx removes blackhole operation on "receiving".
 	UnblackholeRx()
 
-	// PauseTx stops "forwarding" packets; "outgoing" traffic blocks.
-	PauseTx()
-	// UnpauseTx removes "forwarding" pause operation.
-	UnpauseTx()
-
-	// PauseRx stops "receiving" packets; "incoming" traffic blocks.
-	PauseRx()
-	// UnpauseRx removes "receiving" pause operation.
-	UnpauseRx()
-
 	// ResetListener closes and restarts listener.
 	ResetListener() error
 }
@@ -164,9 +149,6 @@ type server struct {
 	listenerMu sync.RWMutex
 	listener   net.Listener
 
-	pauseAcceptMu sync.Mutex
-	pauseAcceptc  chan struct{}
-
 	latencyAcceptMu sync.RWMutex
 	latencyAccept   time.Duration
 
@@ -208,9 +190,8 @@ func NewServer(cfg ServerConfig) Server {
 		donec:  make(chan struct{}),
 		errc:   make(chan error, 16),
 
-		pauseAcceptc: make(chan struct{}),
-		pauseTxc:     make(chan struct{}),
-		pauseRxc:     make(chan struct{}),
+		pauseTxc: make(chan struct{}),
+		pauseRxc: make(chan struct{}),
 	}
 
 	_, fromPort, err := net.SplitHostPort(cfg.From.Host)
@@ -233,7 +214,6 @@ func NewServer(cfg ServerConfig) Server {
 		s.retryInterval = defaultRetryInterval
 	}
 
-	close(s.pauseAcceptc)
 	close(s.pauseTxc)
 	close(s.pauseRxc)
 
@@ -290,15 +270,6 @@ func (s *server) listenAndServe() {
 	close(s.readyc)
 
 	for {
-		s.pauseAcceptMu.Lock()
-		pausec := s.pauseAcceptc
-		s.pauseAcceptMu.Unlock()
-		select {
-		case <-pausec:
-		case <-s.donec:
-			return
-		}
-
 		s.latencyAcceptMu.RLock()
 		lat := s.latencyAccept
 		s.latencyAcceptMu.RUnlock()
@@ -645,37 +616,6 @@ func (s *server) Close() (err error) {
 	return err
 }
 
-func (s *server) PauseAccept() {
-	s.pauseAcceptMu.Lock()
-	s.pauseAcceptc = make(chan struct{})
-	s.pauseAcceptMu.Unlock()
-
-	s.lg.Info(
-		"paused accept",
-		zap.String("from", s.From()),
-		zap.String("to", s.To()),
-	)
-}
-
-func (s *server) UnpauseAccept() {
-	s.pauseAcceptMu.Lock()
-	select {
-	case <-s.pauseAcceptc: // already unpaused
-	case <-s.donec:
-		s.pauseAcceptMu.Unlock()
-		return
-	default:
-		close(s.pauseAcceptc)
-	}
-	s.pauseAcceptMu.Unlock()
-
-	s.lg.Info(
-		"unpaused accept",
-		zap.String("from", s.From()),
-		zap.String("to", s.To()),
-	)
-}
-
 func (s *server) DelayAccept(latency, rv time.Duration) {
 	if latency <= 0 {
 		return

pkg/proxy/server_test.go

@@ -234,55 +234,6 @@ func testServerDelayAccept(t *testing.T, secure bool) {
 	}
 }
 
-func TestServer_PauseTx(t *testing.T) {
-	lg := zaptest.NewLogger(t)
-	scheme := "unix"
-	srcAddr, dstAddr := newUnixAddr(), newUnixAddr()
-	defer func() {
-		os.RemoveAll(srcAddr)
-		os.RemoveAll(dstAddr)
-	}()
-	ln := listen(t, scheme, dstAddr, transport.TLSInfo{})
-	defer ln.Close()
-
-	p := NewServer(ServerConfig{
-		Logger: lg,
-		From:   url.URL{Scheme: scheme, Host: srcAddr},
-		To:     url.URL{Scheme: scheme, Host: dstAddr},
-	})
-
-	waitForServer(t, p)
-
-	defer p.Close()
-
-	p.PauseTx()
-
-	data := []byte("Hello World!")
-	send(t, data, scheme, srcAddr, transport.TLSInfo{})
-
-	recvc := make(chan []byte, 1)
-	go func() {
-		recvc <- receive(t, ln)
-	}()
-
-	select {
-	case d := <-recvc:
-		t.Fatalf("received unexpected data %q during pause", string(d))
-	case <-time.After(200 * time.Millisecond):
-	}
-
-	p.UnpauseTx()
-
-	select {
-	case d := <-recvc:
-		if !bytes.Equal(data, d) {
-			t.Fatalf("expected %q, got %q", string(data), string(d))
-		}
-	case <-time.After(2 * time.Second):
-		t.Fatal("took too long to receive after unpause")
-	}
-}
-
 func TestServer_ModifyTx_corrupt(t *testing.T) {
 	lg := zaptest.NewLogger(t)
 	scheme := "unix"