k3s/pkg/util/net.go

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package util
import (
"errors"
"fmt"
"net"
"os"
"strings"
"github.com/urfave/cli"
apinet "k8s.io/apimachinery/pkg/util/net"
)
// JoinIPs stringifies and joins a list of IP addresses with commas.
func JoinIPs(elems []net.IP) string {
var strs []string
for _, elem := range elems {
strs = append(strs, elem.String())
}
return strings.Join(strs, ",")
}
// JoinIPNets stringifies and joins a list of IP networks with commas.
func JoinIPNets(elems []*net.IPNet) string {
var strs []string
for _, elem := range elems {
strs = append(strs, elem.String())
}
return strings.Join(strs, ",")
}
// GetFirst4Net returns the first IPv4 network from the list of IP networks.
// If no IPv4 addresses are found, an error is raised.
func GetFirst4Net(elems []*net.IPNet) (*net.IPNet, error) {
for _, elem := range elems {
if elem == nil || elem.IP.To4() == nil {
continue
}
return elem, nil
}
return nil, errors.New("no IPv4 CIDRs found")
}
// GetFirst4 returns the first IPv4 address from the list of IP addresses.
// If no IPv4 addresses are found, an error is raised.
func GetFirst4(elems []net.IP) (net.IP, error) {
for _, elem := range elems {
if elem == nil || elem.To4() == nil {
continue
}
return elem, nil
}
return nil, errors.New("no IPv4 address found")
}
// GetFirst4String returns the first IPv4 address from a list of IP address strings.
// If no IPv4 addresses are found, an error is raised.
func GetFirst4String(elems []string) (string, error) {
ips := []net.IP{}
for _, elem := range elems {
for _, v := range strings.Split(elem, ",") {
ips = append(ips, net.ParseIP(v))
}
}
ip, err := GetFirst4(ips)
if err != nil {
return "", err
}
return ip.String(), nil
}
// JoinIP4Nets stringifies and joins a list of IPv4 networks with commas.
func JoinIP4Nets(elems []*net.IPNet) string {
var strs []string
for _, elem := range elems {
if elem != nil && elem.IP.To4() != nil {
strs = append(strs, elem.String())
}
}
return strings.Join(strs, ",")
}
// GetFirst6 returns the first IPv6 address from the list of IP addresses.
// If no IPv6 addresses are found, an error is raised.
func GetFirst6(elems []net.IP) (net.IP, error) {
for _, elem := range elems {
if elem == nil || elem.To16() == nil {
continue
}
return elem, nil
}
return nil, errors.New("no IPv6 address found")
}
// GetFirst6Net returns the first IPv4 network from the list of IP networks.
// If no IPv6 addresses are found, an error is raised.
func GetFirst6Net(elems []*net.IPNet) (*net.IPNet, error) {
for _, elem := range elems {
if elem == nil || elem.IP.To16() == nil {
continue
}
return elem, nil
}
return nil, errors.New("no IPv6 CIDRs found")
}
// GetFirst6String returns the first IPv6 address from a list of IP address strings.
// If no IPv6 addresses are found, an error is raised.
func GetFirst6String(elems []string) (string, error) {
ips := []net.IP{}
for _, elem := range elems {
for _, v := range strings.Split(elem, ",") {
ips = append(ips, net.ParseIP(v))
}
}
ip, err := GetFirst6(ips)
if err != nil {
return "", err
}
return ip.String(), nil
}
// JoinIP6Nets stringifies and joins a list of IPv6 networks with commas.
func JoinIP6Nets(elems []*net.IPNet) string {
var strs []string
for _, elem := range elems {
if elem != nil && elem.IP.To4() == nil {
strs = append(strs, elem.String())
}
}
return strings.Join(strs, ",")
}
// GetHostnameAndIPs takes a node name and list of IPs, usually from CLI args.
// If set, these are used to return the node's name and addresses. If not set,
// the system hostname and primary interface address are returned instead.
func GetHostnameAndIPs(name string, nodeIPs cli.StringSlice) (string, []net.IP, error) {
ips := []net.IP{}
if len(nodeIPs) == 0 {
hostIP, err := apinet.ChooseHostInterface()
if err != nil {
return "", nil, err
}
ips = append(ips, hostIP)
// If IPv6 it's an IPv6 only node
if hostIP.To4() != nil {
hostIPv6, err := apinet.ResolveBindAddress(net.IPv6loopback)
if err == nil && !hostIPv6.Equal(hostIP) {
ips = append(ips, hostIPv6)
}
}
} else {
var err error
ips, err = ParseStringSliceToIPs(nodeIPs)
if err != nil {
return "", nil, fmt.Errorf("invalid node-ip: %w", err)
}
}
if name == "" {
hostname, err := os.Hostname()
if err != nil {
return "", nil, err
}
name = hostname
}
// Use lower case hostname to comply with kubernetes constraint:
// https://github.com/kubernetes/kubernetes/issues/71140
name = strings.ToLower(name)
return name, ips, nil
}
// ParseStringSliceToIPs converts slice of strings that in turn can be lists of comma separated unparsed IP addresses
// into a single slice of net.IP, it returns error if at any point parsing failed
func ParseStringSliceToIPs(s cli.StringSlice) ([]net.IP, error) {
var ips []net.IP
for _, unparsedIP := range s {
for _, v := range strings.Split(unparsedIP, ",") {
ip := net.ParseIP(v)
if ip == nil {
return nil, fmt.Errorf("invalid ip format '%s'", v)
}
ips = append(ips, ip)
}
}
return ips, nil
}
// GetFirstValidIPString returns the first valid address from a list of IP address strings,
// without preference for IP family. If no address are found, an empty string is returned.
func GetFirstValidIPString(s cli.StringSlice) string {
for _, unparsedIP := range s {
for _, v := range strings.Split(unparsedIP, ",") {
if ip := net.ParseIP(v); ip != nil {
return v
}
}
}
return ""
}
// GetFirstIP returns the first IPv4 address from the list of IP addresses.
// If no IPv4 addresses are found, returns the first IPv6 address
// if neither of IPv4 or IPv6 are found an error is raised.
// Additionally matching listen address and IP version is returned.
func GetFirstIP(nodeIPs []net.IP) (net.IP, string, bool, error) {
nodeIP, err := GetFirst4(nodeIPs)
ListenAddress := "0.0.0.0"
IPv6only := false
if err != nil {
nodeIP, err = GetFirst6(nodeIPs)
if err != nil {
return nil, "", false, err
}
ListenAddress = "::"
IPv6only = true
}
return nodeIP, ListenAddress, IPv6only, nil
}
// GetFirstNet returns the first IPv4 network from the list of IP networks.
// If no IPv4 addresses are found, returns the first IPv6 address
// if neither of IPv4 or IPv6 are found an error is raised.
func GetFirstNet(elems []*net.IPNet) (*net.IPNet, error) {
serviceIPRange, err := GetFirst4Net(elems)
if err != nil {
serviceIPRange, err = GetFirst6Net(elems)
if err != nil {
return nil, err
}
}
return serviceIPRange, nil
}
// GetFirstString returns the first IP4 address from a list of IP address strings.
// If no IPv4 addresses are found, returns the first IPv6 address
// if neither of IPv4 or IPv6 are found an error is raised.
func GetFirstString(elems []string) (string, bool, error) {
ip, err := GetFirst4String(elems)
IPv6only := false
if err != nil {
ip, err = GetFirst6String(elems)
if err != nil {
return "", false, err
}
IPv6only = true
}
return ip, IPv6only, nil
}
// IsIPv6OnlyCIDRs returns if
// - all are valid cidrs
// - at least one cidr from v6 family is found
// - v4 family cidr is not found
func IsIPv6OnlyCIDRs(cidrs []*net.IPNet) (bool, error) {
v4Found := false
v6Found := false
for _, cidr := range cidrs {
if cidr == nil {
return false, fmt.Errorf("cidr %v is invalid", cidr)
}
if v4Found && v6Found {
continue
}
if cidr.IP != nil && cidr.IP.To4() == nil {
v6Found = true
continue
}
v4Found = true
}
return !v4Found && v6Found, nil
}
// IPToIPNet converts an IP to an IPNet, using a fully filled mask appropriate for the address family.
func IPToIPNet(ip net.IP) (*net.IPNet, error) {
address := ip.String()
if strings.Contains(address, ":") {
address += "/128"
} else {
address += "/32"
}
_, cidr, err := net.ParseCIDR(address)
return cidr, err
}
// IPStringToIPNet converts an IP string to an IPNet, using a fully filled mask appropriate for the address family.
func IPStringToIPNet(address string) (*net.IPNet, error) {
if strings.Contains(address, ":") {
address += "/128"
} else {
address += "/32"
}
_, cidr, err := net.ParseCIDR(address)
return cidr, err
}