Add forwardingrules.GetILBProtocol func for mixed protocol

pkg/forwardingrules/protocol.go

@@ -0,0 +1,42 @@
+package forwardingrules
+
+import api_v1 "k8s.io/api/core/v1"
+
+const (
+	// ProtocolTCP is the value used for Protocol when creating TCP Forwarding Rule
+	ProtocolTCP = "TCP"
+	// ProtocolUDP is the value used for Protocol when creating UDP Forwarding Rule
+	ProtocolUDP = "UDP"
+	// ProtocolL3 is the value used for Protocol when creating L3 Forwarding Rule.
+	// L3 Forwarding rule allows all the traffic to flow through it regardless of ports
+	// and protocol. When using ProtocolL3 AllPorts option should be used as well.
+	ProtocolL3 = "L3_DEFAULT"
+)
+
+// GetILBProtocol returns the protocol to be used for a Forwarding Rule for an ILB.
+// For ELB please use forwardingrules.NeedsTCP or forwardingrules.NeedsUDP functions.
+func GetILBProtocol(svcPorts []api_v1.ServicePort) string {
+	protocolSet := make(map[api_v1.Protocol]struct{})
+	for _, port := range svcPorts {
+		protocol := port.Protocol
+		if protocol == "" {
+			// Protocol is optional, defaults to TCP
+			protocol = api_v1.ProtocolTCP
+		}
+		protocolSet[protocol] = struct{}{}
+	}
+
+	_, okTCP := protocolSet[api_v1.ProtocolTCP]
+	_, okUDP := protocolSet[api_v1.ProtocolUDP]
+
+	switch {
+	case okTCP && okUDP:
+		return ProtocolL3
+	case okUDP:
+		return ProtocolUDP
+	case okTCP:
+		return ProtocolTCP
+	default:
+		return ProtocolTCP
+	}
+}

pkg/forwardingrules/protocol_test.go

@@ -0,0 +1,75 @@
+package forwardingrules_test
+
+import (
+	"testing"
+
+	api_v1 "k8s.io/api/core/v1"
+	"k8s.io/ingress-gce/pkg/forwardingrules"
+)
+
+func TestGetProtocol(t *testing.T) {
+	tcpPort := api_v1.ServicePort{
+		Protocol: api_v1.ProtocolTCP,
+	}
+	udpPort := api_v1.ServicePort{
+		Protocol: api_v1.ProtocolUDP,
+	}
+	emptyPort := api_v1.ServicePort{}
+
+	testCases := []struct {
+		ports []api_v1.ServicePort
+		want  string
+		desc  string
+	}{
+		{
+			desc:  "no ports",
+			ports: []api_v1.ServicePort{},
+			want:  forwardingrules.ProtocolTCP,
+		},
+		{
+			desc:  "udp single",
+			ports: []api_v1.ServicePort{udpPort},
+			want:  forwardingrules.ProtocolUDP,
+		},
+		{
+			desc:  "udp multiple",
+			ports: []api_v1.ServicePort{udpPort, udpPort},
+			want:  forwardingrules.ProtocolUDP,
+		},
+		{
+			desc:  "tcp single",
+			ports: []api_v1.ServicePort{tcpPort},
+			want:  forwardingrules.ProtocolTCP,
+		},
+		{
+			desc:  "tcp multiple",
+			ports: []api_v1.ServicePort{tcpPort, tcpPort},
+			want:  forwardingrules.ProtocolTCP,
+		},
+		{
+			desc:  "tcp default",
+			ports: []api_v1.ServicePort{emptyPort},
+			want:  forwardingrules.ProtocolTCP,
+		},
+		{
+			desc:  "mixed, udp first",
+			ports: []api_v1.ServicePort{udpPort, tcpPort},
+			want:  forwardingrules.ProtocolL3,
+		},
+		{
+			desc:  "mixed, tcp first",
+			ports: []api_v1.ServicePort{tcpPort, udpPort},
+			want:  forwardingrules.ProtocolL3,
+		},
+	}
+
+	for _, tC := range testCases {
+		t.Run(tC.desc, func(t *testing.T) {
+			got := forwardingrules.GetILBProtocol(tC.ports)
+
+			if got != tC.want {
+				t.Errorf("GetProtocol(_) = %v, want %v", got, tC.want)
+			}
+		})
+	}
+}