TUN-3753: Select http2 protocol when warp routing is enabled

cmd/cloudflared/tunnel/configuration.go

@@ -231,7 +231,13 @@ func prepareTunnelConfig(
 		}
 	}
 
-	protocolSelector, err := connection.NewProtocolSelector(c.String("protocol"), namedTunnel, edgediscovery.HTTP2Percentage, origin.ResolveTTL, log)
+	var warpRoutingService *ingress.WarpRoutingService
+	warpRoutingEnabled := isWarpRoutingEnabled(cfg.WarpRouting, isNamedTunnel)
+	if warpRoutingEnabled {
+		warpRoutingService = ingress.NewWarpRoutingService()
+	}
+
+	protocolSelector, err := connection.NewProtocolSelector(c.String("protocol"), warpRoutingEnabled, namedTunnel, edgediscovery.HTTP2Percentage, origin.ResolveTTL, log)
 	if err != nil {
 		return nil, ingress.Ingress{}, err
 	}
@@ -246,11 +252,6 @@ func prepareTunnelConfig(
 		edgeTLSConfigs[p] = edgeTLSConfig
 	}
 
-	var warpRoutingService *ingress.WarpRoutingService
-	if isWarpRoutingEnabled(cfg.WarpRouting, isNamedTunnel, protocolSelector.Current()) {
-		warpRoutingService = ingress.NewWarpRoutingService()
-	}
-
 	originProxy := origin.NewOriginProxy(ingressRules, warpRoutingService, tags, log)
 	connectionConfig := &connection.Config{
 		OriginProxy:     originProxy,
@@ -292,8 +293,8 @@ func prepareTunnelConfig(
 	}, ingressRules, nil
 }
 
-func isWarpRoutingEnabled(warpConfig config.WarpRoutingConfig, isNamedTunnel bool, protocol connection.Protocol) bool {
+func isWarpRoutingEnabled(warpConfig config.WarpRoutingConfig, isNamedTunnel bool) bool {
-	return warpConfig.Enabled && isNamedTunnel && protocol == connection.HTTP2
+	return warpConfig.Enabled && isNamedTunnel
 }
 
 func isRunningFromTerminal() bool {

connection/protocol.go

@@ -141,16 +141,29 @@ type PercentageFetcher func() (int32, error)
 
 func NewProtocolSelector(
 	protocolFlag string,
+	warpRoutingEnabled bool,
 	namedTunnel *NamedTunnelConfig,
 	fetchFunc PercentageFetcher,
 	ttl time.Duration,
 	log *zerolog.Logger,
 ) (ProtocolSelector, error) {
+	// Classic tunnel is only supported with h2mux
 	if namedTunnel == nil {
 		return &staticProtocolSelector{
 			current: H2mux,
 		}, nil
 	}
+
+	// warp routing can only be served over http2 connections
+	if warpRoutingEnabled {
+		if protocolFlag == H2mux.String() {
+			log.Warn().Msg("Warp routing is only supported by http2 protocol. Upgrading protocol to http2")
+		}
+		return &staticProtocolSelector{
+			current: HTTP2,
+		}, nil
+	}
+
 	if protocolFlag == H2mux.String() {
 		return &staticProtocolSelector{
 			current: H2mux,

connection/protocol_test.go

@@ -10,6 +10,7 @@ import (
 
 const (
 	testNoTTL            = 0
+	noWarpRoutingEnabled = false
 )
 
 var (
@@ -53,6 +54,7 @@ func TestNewProtocolSelector(t *testing.T) {
 		expectedProtocol   Protocol
 		hasFallback        bool
 		expectedFallback   Protocol
+		warpRoutingEnabled bool
 		namedTunnelConfig  *NamedTunnelConfig
 		fetchFunc          PercentageFetcher
 		wantErr            bool
@@ -108,6 +110,36 @@ func TestNewProtocolSelector(t *testing.T) {
 			fetchFunc:         mockFetcher(100),
 			namedTunnelConfig: testNamedTunnelConfig,
 		},
+		{
+			name:               "warp routing requesting h2mux",
+			protocol:           "h2mux",
+			expectedProtocol:   HTTP2,
+			hasFallback:        false,
+			expectedFallback:   H2mux,
+			fetchFunc:          mockFetcher(100),
+			warpRoutingEnabled: true,
+			namedTunnelConfig:  testNamedTunnelConfig,
+		},
+		{
+			name:               "warp routing http2",
+			protocol:           "http2",
+			expectedProtocol:   HTTP2,
+			hasFallback:        false,
+			expectedFallback:   H2mux,
+			fetchFunc:          mockFetcher(100),
+			warpRoutingEnabled: true,
+			namedTunnelConfig:  testNamedTunnelConfig,
+		},
+		{
+			name:               "warp routing auto",
+			protocol:           "auto",
+			expectedProtocol:   HTTP2,
+			hasFallback:        false,
+			expectedFallback:   H2mux,
+			fetchFunc:          mockFetcher(100),
+			warpRoutingEnabled: true,
+			namedTunnelConfig:  testNamedTunnelConfig,
+		},
 		{
 			// None named tunnel can only use h2mux, so specifying an unknown protocol is not an error
 			name:             "classic tunnel unknown protocol",
@@ -131,7 +163,7 @@ func TestNewProtocolSelector(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		selector, err := NewProtocolSelector(test.protocol, test.namedTunnelConfig, test.fetchFunc, testNoTTL, &log)
+		selector, err := NewProtocolSelector(test.protocol, test.warpRoutingEnabled, test.namedTunnelConfig, test.fetchFunc, testNoTTL, &log)
 		if test.wantErr {
 			assert.Error(t, err, fmt.Sprintf("test %s failed", test.name))
 		} else {
@@ -148,7 +180,7 @@ func TestNewProtocolSelector(t *testing.T) {
 
 func TestAutoProtocolSelectorRefresh(t *testing.T) {
 	fetcher := dynamicMockFetcher{}
-	selector, err := NewProtocolSelector("auto", testNamedTunnelConfig, fetcher.fetch(), testNoTTL, &log)
+	selector, err := NewProtocolSelector("auto", noWarpRoutingEnabled, testNamedTunnelConfig, fetcher.fetch(), testNoTTL, &log)
 	assert.NoError(t, err)
 	assert.Equal(t, H2mux, selector.Current())
 
@@ -177,7 +209,7 @@ func TestAutoProtocolSelectorRefresh(t *testing.T) {
 
 func TestHTTP2ProtocolSelectorRefresh(t *testing.T) {
 	fetcher := dynamicMockFetcher{}
-	selector, err := NewProtocolSelector("http2", testNamedTunnelConfig, fetcher.fetch(), testNoTTL, &log)
+	selector, err := NewProtocolSelector("http2", noWarpRoutingEnabled, testNamedTunnelConfig, fetcher.fetch(), testNoTTL, &log)
 	assert.NoError(t, err)
 	assert.Equal(t, HTTP2, selector.Current())
 
@@ -206,7 +238,7 @@ func TestHTTP2ProtocolSelectorRefresh(t *testing.T) {
 
 func TestProtocolSelectorRefreshTTL(t *testing.T) {
 	fetcher := dynamicMockFetcher{percentage: 100}
-	selector, err := NewProtocolSelector("auto", testNamedTunnelConfig, fetcher.fetch(), time.Hour, &log)
+	selector, err := NewProtocolSelector("auto", noWarpRoutingEnabled, testNamedTunnelConfig, fetcher.fetch(), time.Hour, &log)
 	assert.NoError(t, err)
 	assert.Equal(t, HTTP2, selector.Current())
 

origin/tunnel_test.go

@@ -40,8 +40,10 @@ func TestWaitForBackoffFallback(t *testing.T) {
 	mockFetcher := dynamicMockFetcher{
 		percentage: 0,
 	}
+	warpRoutingEnabled := false
 	protocolSelector, err := connection.NewProtocolSelector(
 		connection.HTTP2.String(),
+		warpRoutingEnabled,
 		namedTunnel,
 		mockFetcher.fetch(),
 		resolveTTL,