pkg/proxy: refactor npa.GetNodeIPs

Signed-off-by: Daman Arora <aroradaman@gmail.com>

pkg/proxy/util/nodeport_addresses.go

@@ -94,38 +94,7 @@ func (npa *NodePortAddresses) MatchAll() bool {
 // IPs are found, it returns an empty list.
 // NetworkInterfacer is injected for test purpose.
 func (npa *NodePortAddresses) GetNodeIPs(nw NetworkInterfacer) ([]net.IP, error) {
-	addrs, err := nw.InterfaceAddrs()
+	return FilterInterfaceAddrsByCIDRs(nw, npa.cidrs)
-	if err != nil {
-		return nil, fmt.Errorf("error listing all interfaceAddrs from host, error: %v", err)
-	}
-
-	// Use a map to dedup matches
-	addresses := make(map[string]net.IP)
-	for _, cidr := range npa.cidrs {
-		for _, addr := range addrs {
-			var ip net.IP
-			// nw.InterfaceAddrs may return net.IPAddr or net.IPNet on windows, and it will return net.IPNet on linux.
-			switch v := addr.(type) {
-			case *net.IPAddr:
-				ip = v.IP
-			case *net.IPNet:
-				ip = v.IP
-			default:
-				continue
-			}
-
-			if cidr.Contains(ip) {
-				addresses[ip.String()] = ip
-			}
-		}
-	}
-
-	ips := make([]net.IP, 0, len(addresses))
-	for _, ip := range addresses {
-		ips = append(ips, ip)
-	}
-
-	return ips, nil
 }
 
 // ContainsIPv4Loopback returns true if npa's CIDRs contain an IPv4 loopback address.

pkg/proxy/util/utils.go

@@ -241,3 +241,49 @@ func IsVIPMode(ing v1.LoadBalancerIngress) bool {
 	}
 	return *ing.IPMode == v1.LoadBalancerIPModeVIP
 }
+
+// FilterInterfaceAddrsByCIDRs filters the IP addresses of the provided NetworkInterfacer,
+// returning only those that belong to any of the CIDRs specified in the given list.
+func FilterInterfaceAddrsByCIDRs(nw NetworkInterfacer, cidrs []*net.IPNet) ([]net.IP, error) {
+	addrs, err := nw.InterfaceAddrs()
+	if err != nil {
+		return nil, fmt.Errorf("error listing all interfaceAddrs from host, error: %w", err)
+	}
+
+	// Use a map to dedup matches
+	addresses := make(map[string]net.IP)
+	for _, cidr := range cidrs {
+		for _, addr := range addrs {
+			var ip net.IP
+			// nw.InterfaceAddrs may return net.IPAddr or net.IPNet on windows, and it will return net.IPNet on linux.
+			switch v := addr.(type) {
+			case *net.IPAddr:
+				ip = v.IP
+			case *net.IPNet:
+				ip = v.IP
+			default:
+				continue
+			}
+
+			if cidr.Contains(ip) {
+				addresses[ip.String()] = ip
+			}
+		}
+	}
+
+	ips := make([]net.IP, 0, len(addresses))
+	for _, ip := range addresses {
+		ips = append(ips, ip)
+	}
+
+	return ips, nil
+}
+
+// FilterInterfaceAddrsByCIDRStrings is a wrapper around FilterInterfaceAddrsByCIDRs which accepts CIDRs as list of strings.
+func FilterInterfaceAddrsByCIDRStrings(nw NetworkInterfacer, cidrStrings []string) ([]net.IP, error) {
+	cidrs, err := netutils.ParseCIDRs(cidrStrings)
+	if err != nil {
+		return nil, err
+	}
+	return FilterInterfaceAddrsByCIDRs(nw, cidrs)
+}

pkg/proxy/util/utils_test.go

@@ -21,9 +21,12 @@ import (
 	"reflect"
 	"testing"
 
+	"github.com/stretchr/testify/require"
+
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/sets"
+	proxyutiltest "k8s.io/kubernetes/pkg/proxy/util/testing"
 	netutils "k8s.io/utils/net"
 )
 
@@ -703,3 +706,58 @@ func TestIsZeroCIDR(t *testing.T) {
 		})
 	}
 }
+
+func TestFilterInterfaceAddrsByCIDRs(t *testing.T) {
+	networkInterfacer := proxyutiltest.NewFakeNetwork()
+	var itf net.Interface
+	var addrs []net.Addr
+	itf = net.Interface{Index: 0, MTU: 0, Name: "eth1", HardwareAddr: nil, Flags: 0}
+	addrs = []net.Addr{
+		&net.IPNet{IP: netutils.ParseIPSloppy("10.10.10.10"), Mask: net.CIDRMask(24, 32)},
+		&net.IPNet{IP: netutils.ParseIPSloppy("2001:db8::1"), Mask: net.CIDRMask(64, 128)},
+	}
+	networkInterfacer.AddInterfaceAddr(&itf, addrs)
+
+	itf = net.Interface{Index: 0, MTU: 0, Name: "eth2", HardwareAddr: nil, Flags: 0}
+	addrs = []net.Addr{
+		&net.IPNet{IP: netutils.ParseIPSloppy("192.168.0.2"), Mask: net.CIDRMask(24, 32)},
+		&net.IPNet{IP: netutils.ParseIPSloppy("fd00:4321::2"), Mask: net.CIDRMask(64, 128)},
+	}
+	networkInterfacer.AddInterfaceAddr(&itf, addrs)
+
+	testCases := []struct {
+		name        string
+		cidrStrings []string
+		expected    []string
+	}{
+		{
+			name:        "ipv4",
+			cidrStrings: []string{"192.168.0.0/24"},
+			expected:    []string{"192.168.0.2"},
+		},
+		{
+			name:        "ipv6",
+			cidrStrings: []string{"fd00:4321::/64"},
+			expected:    []string{"fd00:4321::2"},
+		},
+		{
+			name:        "dual stack",
+			cidrStrings: []string{"10.10.0.0/16", "2001:db8::/64"},
+			expected:    []string{"10.10.10.10", "2001:db8::1"},
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			cidrs, err := netutils.ParseCIDRs(tc.cidrStrings)
+			require.NoError(t, err)
+
+			ips, err := FilterInterfaceAddrsByCIDRs(networkInterfacer, cidrs)
+			require.NoError(t, err)
+			var expected []net.IP
+			for i := range tc.expected {
+				expected = append(expected, netutils.ParseIPSloppy(tc.expected[i]))
+			}
+			require.Equal(t, expected, ips)
+		})
+	}
+}