add test scenario

Author: NihaNallappagari

azure-ipam/ipam_test.go

@@ -58,6 +58,33 @@ func (c *MockCNSClient) RequestIPAddress(ctx context.Context, ipconfig cns.IPCon
 			},
 		}
 		return result, nil
+	case "nilGateway":
+		result := &cns.IPConfigResponse{
+			PodIpInfo: cns.PodIpInfo{
+				PodIPConfig: cns.IPSubnet{
+					IPAddress:    "10.0.1.10",
+					PrefixLength: 24,
+				},
+				NetworkContainerPrimaryIPConfig: cns.IPConfiguration{
+					IPSubnet: cns.IPSubnet{
+						IPAddress:    "10.0.1.0",
+						PrefixLength: 24,
+					},
+					DNSServers:       nil,
+					GatewayIPAddress: "", // nil/empty gateway
+				},
+				HostPrimaryIPInfo: cns.HostIPInfo{
+					Gateway:   "",
+					PrimaryIP: "10.0.0.1",
+					Subnet:    "10.0.0.0/24",
+				},
+			},
+			Response: cns.Response{
+				ReturnCode: 0,
+				Message:    "",
+			},
+		}
+		return result, nil
 	default:
 		result := &cns.IPConfigResponse{
 			PodIpInfo: cns.PodIpInfo{
@@ -92,7 +119,7 @@ func (c *MockCNSClient) RequestIPs(ctx context.Context, ipconfig cns.IPConfigsRe
 	switch ipconfig.InfraContainerID {
 	case "failRequestCNSArgs":
 		return nil, errFoo
-	case "happyArgsSingle", "failProcessCNSRespSingleIP", "failRequestCNSArgsSingleIP":
+	case "happyArgsSingle", "failProcessCNSRespSingleIP", "failRequestCNSArgsSingleIP", "nilGateway":
 		e := &client.CNSClientError{}
 		e.Code = types.UnsupportedAPI
 		e.Err = errUnsupportedAPI
@@ -129,8 +156,8 @@ func (c *MockCNSClient) RequestIPs(ctx context.Context, ipconfig cns.IPConfigsRe
 							IPAddress:    "fd11:1234::",
 							PrefixLength: 112,
 						},
-						DNSServers:       nil,
-						GatewayIPAddress: "fe80::1234:5678:9abc",
+						DNSServers:         nil,
+						GatewayIPv6Address: "fe80::1234:5678:9abc",
 					},
 					HostPrimaryIPInfo: cns.HostIPInfo{
 						Gateway:   "fe80::1234:5678:9abc",
@@ -177,8 +204,8 @@ func (c *MockCNSClient) RequestIPs(ctx context.Context, ipconfig cns.IPConfigsRe
 							IPAddress:    "fd11:1234::",
 							PrefixLength: 120,
 						},
-						DNSServers:       nil,
-						GatewayIPAddress: "fe80::1234:5678:9abc",
+						DNSServers:         nil,
+						GatewayIPv6Address: "fe80::1234:5678:9abc",
 					},
 					HostPrimaryIPInfo: cns.HostIPInfo{
 						Gateway:   "fe80::1234:5678:9abc",
@@ -287,6 +314,7 @@ func TestCmdAdd(t *testing.T) {
 							IP:   net.IPv4(10, 0, 1, 10),
 							Mask: net.CIDRMask(24, 32),
 						},
+						Gateway: net.IPv4(10, 0, 0, 1),
 					},
 				},
 				DNS: cniTypes.DNS{},
@@ -304,12 +332,31 @@ func TestCmdAdd(t *testing.T) {
 							IP:   net.IPv4(10, 0, 1, 10),
 							Mask: net.CIDRMask(24, 32),
 						},
+						Gateway: net.IPv4(10, 0, 0, 1),
 					},
 					{
 						Address: net.IPNet{
 							IP:   net.ParseIP("fd11:1234::1"),
 							Mask: net.CIDRMask(120, 128),
 						},
+						Gateway: net.ParseIP("fe80::1234:5678:9abc"),
+					},
+				},
+				DNS: cniTypes.DNS{},
+			},
+			wantErr: false,
+		},
+		{
+			name: "CNI add with nil gateway IP",
+			args: buildArgs("nilGateway", happyPodArgs, happyNetConfByteArr),
+			want: &types100.Result{
+				CNIVersion: "1.0.0",
+				IPs: []*types100.IPConfig{
+					{
+						Address: net.IPNet{
+							IP:   net.IPv4(10, 0, 1, 10),
+							Mask: net.CIDRMask(24, 32),
+						},
 					},
 				},
 				DNS: cniTypes.DNS{},

azure-ipam/ipconfig/ipconfig.go

@@ -84,14 +84,16 @@ func ProcessIPConfigsResp(resp *cns.IPConfigsResponse) (*[]netip.Prefix, *[]net.
 
 		var gatewayStr string
 		if podIPNet.Addr().Is4() {
-			gatewayStr = podInfo.NetworkContainerPrimaryIPConfig.GatewayIPAddress
+			gatewayStr = resp.PodIPInfo[i].NetworkContainerPrimaryIPConfig.GatewayIPAddress
 		} else if podIPNet.Addr().Is6() {
-			gatewayStr = podInfo.NetworkContainerPrimaryIPConfig.GatewayIPv6Address
+			gatewayStr = resp.PodIPInfo[i].NetworkContainerPrimaryIPConfig.GatewayIPv6Address
 		}
 
-		gatewayIP := net.ParseIP(gatewayStr)
-		if gatewayIP == nil {
-			return nil, nil, errors.Errorf("failed to parse gateway IP %q for pod ip %s", gatewayStr, podInfo.PodIPConfig.IPAddress)
+		if gatewayStr != "" {
+			gatewayIP = net.ParseIP(gatewayStr)
+			if gatewayIP == nil {
+				return nil, nil, errors.Errorf("failed to parse gateway IP %q for pod ip %s", gatewayStr, resp.PodIPInfo[i].PodIPConfig.IPAddress)
+			}
 		}
 		gatewaysIPs[i] = gatewayIP
 	}