Add support for dual stack / IPv6 for node IPs. Allow defining internal IPs as CIDR ranges.

Author: marnixbouhuis

pkg/cloud-controller-manager/instance.go

@@ -4,8 +4,9 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"net"
+	"net/netip"
 	"slices"
+	"strings"
 	"sync"
 
 	ctlkubevirtv1 "github.com/harvester/harvester/pkg/generated/controllers/kubevirt.io/v1"
@@ -70,7 +71,10 @@ func (i *instanceManager) InstanceMetadata(ctx context.Context, node *v1.Node) (
 		meta.Zone = zone
 	}
 
-	meta.NodeAddresses = getNodeAddresses(node, vmi)
+	meta.NodeAddresses, err = getNodeAddresses(node, vmi)
+	if err != nil {
+		return nil, err
+	}
 
 	return meta, nil
 }
@@ -84,46 +88,138 @@ func (i *instanceManager) getVM(node *v1.Node) (*kubevirtv1.VirtualMachine, erro
 }
 
 // getNodeAddresses return nodeAddresses only when the value of annotation `alpha.kubernetes.io/provided-node-ip` is not empty
-func getNodeAddresses(node *v1.Node, vmi *kubevirtv1.VirtualMachineInstance) []v1.NodeAddress {
-	providedNodeIP, ok := node.Annotations[api.AnnotationAlphaProvidedIPAddr]
-	if !ok {
-		return nil
-	}
-
-	aiIPs, err := getAdditionalInternalIPs(node)
+func getNodeAddresses(node *v1.Node, vmi *kubevirtv1.VirtualMachineInstance) ([]v1.NodeAddress, error) {
+	internalIPRanges, err := getInternalIPRanges(node)
 	if err != nil {
-		// if additional IPs are not correctly marked, only log an error, do not return this error
-		logrus.WithFields(logrus.Fields{
-			"namespace": node.Namespace,
-			"name":      node.Name,
-		}).Debugf("%s, skip it", err.Error())
+		return nil, err
 	}
 
-	nodeAddresses := make([]v1.NodeAddress, 0, len(vmi.Spec.Networks)+1)
+	// Optimistically assume that for every interface have one IP. Add one for the hostname address that we add later.
+	// Since the amount of IP addresses is probably very limited this should be fine.
+	nodeAddresses := make([]v1.NodeAddress, 0, len(vmi.Status.Interfaces)+1)
 
+	// Build a list of network names (names of NICs) on the VM.
+	networkNames := make([]string, 0, len(vmi.Spec.Networks))
 	for _, network := range vmi.Spec.Networks {
-		for _, networkInterface := range vmi.Status.Interfaces {
-			if network.Name == networkInterface.Name {
-				if ip := net.ParseIP(networkInterface.IP); ip != nil && ip.To4() != nil {
-					nodeAddr := v1.NodeAddress{
-						Address: networkInterface.IP,
-					}
-					if networkInterface.IP == providedNodeIP || (aiIPs != nil && slices.Contains(aiIPs, networkInterface.IP)) {
-						nodeAddr.Type = v1.NodeInternalIP
-					} else {
-						nodeAddr.Type = v1.NodeExternalIP
-					}
-					nodeAddresses = append(nodeAddresses, nodeAddr)
+		networkNames = append(networkNames, network.Name)
+	}
+
+	// Find all IP addresses of the VM
+	for _, networkInterface := range vmi.Status.Interfaces {
+		// The interface list might contain interfaces that do not belong to any NIC of the VM. Filter them out.
+		if !slices.Contains(networkNames, networkInterface.Name) {
+			// Ignore interface since it does not belong to one of the NICs.
+			continue
+		}
+
+		for _, ipStr := range networkInterface.IPs {
+			ip, err := netip.ParseAddr(ipStr)
+			if err != nil {
+				// Failed to parse IP, skip it
+				logrus.WithFields(logrus.Fields{
+					"namespace": node.Namespace,
+					"name":      node.Name,
+				}).Warnf("Unable to parse IP %s, skip it: %s", ipStr, err.Error())
+				continue
+			}
+
+			// Determine if the IP should be listed as an internal or external IP.
+			ipType := v1.NodeExternalIP
+			for _, internalPrefix := range internalIPRanges {
+				if internalPrefix.Contains(ip) {
+					// IP is an internal IP, no need to check further.
+					ipType = v1.NodeInternalIP
+					break
 				}
 			}
+
+			nodeAddresses = append(nodeAddresses, v1.NodeAddress{
+				Type:    ipType,
+				Address: ip.String(),
+			})
 		}
 	}
+
 	nodeAddresses = append(nodeAddresses, v1.NodeAddress{
 		Type:    v1.NodeHostName,
 		Address: node.Name,
 	})
 
-	return nodeAddresses
+	return nodeAddresses, nil
+}
+
+func getInternalIPRanges(node *v1.Node) ([]netip.Prefix, error) {
+	internalIPRanges := make([]netip.Prefix, 0, 1) // Most of the time we would only have 1 internal range defined, the provided node IP
+
+	// Kubelet sets this node annotation if the --node-ip flag is set and an external cloud provider is used
+	providedNodeIP, ok := node.Annotations[api.AnnotationAlphaProvidedIPAddr]
+	if !ok {
+		// Annotation is not set, this could be because we are running in a dual stack setup.
+		// Assume all IPs are internal IPs.
+		internalIPRanges = append(internalIPRanges, netip.MustParsePrefix("0.0.0.0/0"))
+		internalIPRanges = append(internalIPRanges, netip.MustParsePrefix("::/0"))
+		return internalIPRanges, nil
+	}
+
+	// We got an IP from kubelet, parse it and convert it to a prefix containing only this IP
+	nodeIPRange, err := ipStringToPrefix(providedNodeIP)
+	if err != nil {
+		return nil, fmt.Errorf("annotation \"%s\" is invalid: %w", api.AnnotationAlphaProvidedIPAddr, err)
+	}
+	internalIPRanges = append(internalIPRanges, nodeIPRange)
+
+	// Support marking extra IPs as internal
+	extraInternalIPs, err := getAdditionalInternalIPs(node)
+	if err != nil {
+		// Unable to parse extra provided internal IP ranges, ignore them.
+		logrus.WithFields(logrus.Fields{
+			"namespace": node.Namespace,
+			"name":      node.Name,
+		}).Warnf("%s, skip it", err.Error())
+
+		// Return list without extra user defined IP ranges.
+		return internalIPRanges, nil
+	}
+
+	for _, extraInternalIP := range extraInternalIPs {
+		extraRange, err := ipStringToPrefix(extraInternalIP)
+		if err != nil {
+			// IP (range) malformed, skip it.
+			logrus.WithFields(logrus.Fields{
+				"namespace": node.Namespace,
+				"name":      node.Name,
+			}).Warnf("Unable to parse IP %s, skip it: %s", extraInternalIP, err.Error())
+			continue
+		}
+		internalIPRanges = append(internalIPRanges, extraRange)
+	}
+
+	return internalIPRanges, nil
+}
+
+// ipStringToPrefix converts an IP / CIDR range to a netip.Prefix. It supports IPv4 and IPv6 addresses.
+// If a plain IP address is given, it returns a Prefix that only contains this IP.
+// If a CIDR range is given, it returns a Prefix that contains the whole range.
+func ipStringToPrefix(str string) (netip.Prefix, error) {
+	if strings.Contains(str, "/") {
+		// CIDR notation
+		return netip.ParsePrefix(str)
+	}
+
+	// Plain IP address
+	addr, err := netip.ParseAddr(str)
+	if err != nil {
+		return netip.Prefix{}, fmt.Errorf("failed to parse IP address \"%s\": %w", str, err)
+	}
+
+	// For a single IPv4 address, the prefix length is 32; for IPv6, it's 128.
+	prefixLen := 32
+	if addr.Is6() {
+		prefixLen = 128
+	}
+
+	// Create a prefix with the single address in it.
+	return addr.Prefix(prefixLen)
 }
 
 // User may want to mark some IPs of the node also as internal