(feat) Add auto-discovery in k8s | Adarsh

vendor/k8s.io/apimachinery/pkg/util/net/http.go

@@ -0,0 +1,445 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"crypto/tls"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"os"
+	"path"
+	"strconv"
+	"strings"
+
+	"golang.org/x/net/http2"
+	"k8s.io/klog"
+)
+
+// JoinPreservingTrailingSlash does a path.Join of the specified elements,
+// preserving any trailing slash on the last non-empty segment
+func JoinPreservingTrailingSlash(elem ...string) string {
+	// do the basic path join
+	result := path.Join(elem...)
+
+	// find the last non-empty segment
+	for i := len(elem) - 1; i >= 0; i-- {
+		if len(elem[i]) > 0 {
+			// if the last segment ended in a slash, ensure our result does as well
+			if strings.HasSuffix(elem[i], "/") && !strings.HasSuffix(result, "/") {
+				result += "/"
+			}
+			break
+		}
+	}
+
+	return result
+}
+
+// IsProbableEOF returns true if the given error resembles a connection termination
+// scenario that would justify assuming that the watch is empty.
+// These errors are what the Go http stack returns back to us which are general
+// connection closure errors (strongly correlated) and callers that need to
+// differentiate probable errors in connection behavior between normal "this is
+// disconnected" should use the method.
+func IsProbableEOF(err error) bool {
+	if err == nil {
+		return false
+	}
+	if uerr, ok := err.(*url.Error); ok {
+		err = uerr.Err
+	}
+	msg := err.Error()
+	switch {
+	case err == io.EOF:
+		return true
+	case msg == "http: can't write HTTP request on broken connection":
+		return true
+	case strings.Contains(msg, "http2: server sent GOAWAY and closed the connection"):
+		return true
+	case strings.Contains(msg, "connection reset by peer"):
+		return true
+	case strings.Contains(strings.ToLower(msg), "use of closed network connection"):
+		return true
+	}
+	return false
+}
+
+var defaultTransport = http.DefaultTransport.(*http.Transport)
+
+// SetOldTransportDefaults applies the defaults from http.DefaultTransport
+// for the Proxy, Dial, and TLSHandshakeTimeout fields if unset
+func SetOldTransportDefaults(t *http.Transport) *http.Transport {
+	if t.Proxy == nil || isDefault(t.Proxy) {
+		// http.ProxyFromEnvironment doesn't respect CIDRs and that makes it impossible to exclude things like pod and service IPs from proxy settings
+		// ProxierWithNoProxyCIDR allows CIDR rules in NO_PROXY
+		t.Proxy = NewProxierWithNoProxyCIDR(http.ProxyFromEnvironment)
+	}
+	// If no custom dialer is set, use the default context dialer
+	if t.DialContext == nil && t.Dial == nil {
+		t.DialContext = defaultTransport.DialContext
+	}
+	if t.TLSHandshakeTimeout == 0 {
+		t.TLSHandshakeTimeout = defaultTransport.TLSHandshakeTimeout
+	}
+	return t
+}
+
+// SetTransportDefaults applies the defaults from http.DefaultTransport
+// for the Proxy, Dial, and TLSHandshakeTimeout fields if unset
+func SetTransportDefaults(t *http.Transport) *http.Transport {
+	t = SetOldTransportDefaults(t)
+	// Allow clients to disable http2 if needed.
+	if s := os.Getenv("DISABLE_HTTP2"); len(s) > 0 {
+		klog.Infof("HTTP2 has been explicitly disabled")
+	} else {
+		if err := http2.ConfigureTransport(t); err != nil {
+			klog.Warningf("Transport failed http2 configuration: %v", err)
+		}
+	}
+	return t
+}
+
+type RoundTripperWrapper interface {
+	http.RoundTripper
+	WrappedRoundTripper() http.RoundTripper
+}
+
+type DialFunc func(ctx context.Context, net, addr string) (net.Conn, error)
+
+func DialerFor(transport http.RoundTripper) (DialFunc, error) {
+	if transport == nil {
+		return nil, nil
+	}
+
+	switch transport := transport.(type) {
+	case *http.Transport:
+		// transport.DialContext takes precedence over transport.Dial
+		if transport.DialContext != nil {
+			return transport.DialContext, nil
+		}
+		// adapt transport.Dial to the DialWithContext signature
+		if transport.Dial != nil {
+			return func(ctx context.Context, net, addr string) (net.Conn, error) {
+				return transport.Dial(net, addr)
+			}, nil
+		}
+		// otherwise return nil
+		return nil, nil
+	case RoundTripperWrapper:
+		return DialerFor(transport.WrappedRoundTripper())
+	default:
+		return nil, fmt.Errorf("unknown transport type: %T", transport)
+	}
+}
+
+type TLSClientConfigHolder interface {
+	TLSClientConfig() *tls.Config
+}
+
+func TLSClientConfig(transport http.RoundTripper) (*tls.Config, error) {
+	if transport == nil {
+		return nil, nil
+	}
+
+	switch transport := transport.(type) {
+	case *http.Transport:
+		return transport.TLSClientConfig, nil
+	case TLSClientConfigHolder:
+		return transport.TLSClientConfig(), nil
+	case RoundTripperWrapper:
+		return TLSClientConfig(transport.WrappedRoundTripper())
+	default:
+		return nil, fmt.Errorf("unknown transport type: %T", transport)
+	}
+}
+
+func FormatURL(scheme string, host string, port int, path string) *url.URL {
+	return &url.URL{
+		Scheme: scheme,
+		Host:   net.JoinHostPort(host, strconv.Itoa(port)),
+		Path:   path,
+	}
+}
+
+func GetHTTPClient(req *http.Request) string {
+	if ua := req.UserAgent(); len(ua) != 0 {
+		return ua
+	}
+	return "unknown"
+}
+
+// SourceIPs splits the comma separated X-Forwarded-For header or returns the X-Real-Ip header or req.RemoteAddr,
+// in that order, ignoring invalid IPs. It returns nil if all of these are empty or invalid.
+func SourceIPs(req *http.Request) []net.IP {
+	hdr := req.Header
+	// First check the X-Forwarded-For header for requests via proxy.
+	hdrForwardedFor := hdr.Get("X-Forwarded-For")
+	forwardedForIPs := []net.IP{}
+	if hdrForwardedFor != "" {
+		// X-Forwarded-For can be a csv of IPs in case of multiple proxies.
+		// Use the first valid one.
+		parts := strings.Split(hdrForwardedFor, ",")
+		for _, part := range parts {
+			ip := net.ParseIP(strings.TrimSpace(part))
+			if ip != nil {
+				forwardedForIPs = append(forwardedForIPs, ip)
+			}
+		}
+	}
+	if len(forwardedForIPs) > 0 {
+		return forwardedForIPs
+	}
+
+	// Try the X-Real-Ip header.
+	hdrRealIp := hdr.Get("X-Real-Ip")
+	if hdrRealIp != "" {
+		ip := net.ParseIP(hdrRealIp)
+		if ip != nil {
+			return []net.IP{ip}
+		}
+	}
+
+	// Fallback to Remote Address in request, which will give the correct client IP when there is no proxy.
+	// Remote Address in Go's HTTP server is in the form host:port so we need to split that first.
+	host, _, err := net.SplitHostPort(req.RemoteAddr)
+	if err == nil {
+		if remoteIP := net.ParseIP(host); remoteIP != nil {
+			return []net.IP{remoteIP}
+		}
+	}
+
+	// Fallback if Remote Address was just IP.
+	if remoteIP := net.ParseIP(req.RemoteAddr); remoteIP != nil {
+		return []net.IP{remoteIP}
+	}
+
+	return nil
+}
+
+// Extracts and returns the clients IP from the given request.
+// Looks at X-Forwarded-For header, X-Real-Ip header and request.RemoteAddr in that order.
+// Returns nil if none of them are set or is set to an invalid value.
+func GetClientIP(req *http.Request) net.IP {
+	ips := SourceIPs(req)
+	if len(ips) == 0 {
+		return nil
+	}
+	return ips[0]
+}
+
+// Prepares the X-Forwarded-For header for another forwarding hop by appending the previous sender's
+// IP address to the X-Forwarded-For chain.
+func AppendForwardedForHeader(req *http.Request) {
+	// Copied from net/http/httputil/reverseproxy.go:
+	if clientIP, _, err := net.SplitHostPort(req.RemoteAddr); err == nil {
+		// If we aren't the first proxy retain prior
+		// X-Forwarded-For information as a comma+space
+		// separated list and fold multiple headers into one.
+		if prior, ok := req.Header["X-Forwarded-For"]; ok {
+			clientIP = strings.Join(prior, ", ") + ", " + clientIP
+		}
+		req.Header.Set("X-Forwarded-For", clientIP)
+	}
+}
+
+var defaultProxyFuncPointer = fmt.Sprintf("%p", http.ProxyFromEnvironment)
+
+// isDefault checks to see if the transportProxierFunc is pointing to the default one
+func isDefault(transportProxier func(*http.Request) (*url.URL, error)) bool {
+	transportProxierPointer := fmt.Sprintf("%p", transportProxier)
+	return transportProxierPointer == defaultProxyFuncPointer
+}
+
+// NewProxierWithNoProxyCIDR constructs a Proxier function that respects CIDRs in NO_PROXY and delegates if
+// no matching CIDRs are found
+func NewProxierWithNoProxyCIDR(delegate func(req *http.Request) (*url.URL, error)) func(req *http.Request) (*url.URL, error) {
+	// we wrap the default method, so we only need to perform our check if the NO_PROXY (or no_proxy) envvar has a CIDR in it
+	noProxyEnv := os.Getenv("NO_PROXY")
+	if noProxyEnv == "" {
+		noProxyEnv = os.Getenv("no_proxy")
+	}
+	noProxyRules := strings.Split(noProxyEnv, ",")
+
+	cidrs := []*net.IPNet{}
+	for _, noProxyRule := range noProxyRules {
+		_, cidr, _ := net.ParseCIDR(noProxyRule)
+		if cidr != nil {
+			cidrs = append(cidrs, cidr)
+		}
+	}
+
+	if len(cidrs) == 0 {
+		return delegate
+	}
+
+	return func(req *http.Request) (*url.URL, error) {
+		ip := net.ParseIP(req.URL.Hostname())
+		if ip == nil {
+			return delegate(req)
+		}
+
+		for _, cidr := range cidrs {
+			if cidr.Contains(ip) {
+				return nil, nil
+			}
+		}
+
+		return delegate(req)
+	}
+}
+
+// DialerFunc implements Dialer for the provided function.
+type DialerFunc func(req *http.Request) (net.Conn, error)
+
+func (fn DialerFunc) Dial(req *http.Request) (net.Conn, error) {
+	return fn(req)
+}
+
+// Dialer dials a host and writes a request to it.
+type Dialer interface {
+	// Dial connects to the host specified by req's URL, writes the request to the connection, and
+	// returns the opened net.Conn.
+	Dial(req *http.Request) (net.Conn, error)
+}
+
+// ConnectWithRedirects uses dialer to send req, following up to 10 redirects (relative to
+// originalLocation). It returns the opened net.Conn and the raw response bytes.
+// If requireSameHostRedirects is true, only redirects to the same host are permitted.
+func ConnectWithRedirects(originalMethod string, originalLocation *url.URL, header http.Header, originalBody io.Reader, dialer Dialer, requireSameHostRedirects bool) (net.Conn, []byte, error) {
+	const (
+		maxRedirects    = 9     // Fail on the 10th redirect
+		maxResponseSize = 16384 // play it safe to allow the potential for lots of / large headers
+	)
+
+	var (
+		location         = originalLocation
+		method           = originalMethod
+		intermediateConn net.Conn
+		rawResponse      = bytes.NewBuffer(make([]byte, 0, 256))
+		body             = originalBody
+	)
+
+	defer func() {
+		if intermediateConn != nil {
+			intermediateConn.Close()
+		}
+	}()
+
+redirectLoop:
+	for redirects := 0; ; redirects++ {
+		if redirects > maxRedirects {
+			return nil, nil, fmt.Errorf("too many redirects (%d)", redirects)
+		}
+
+		req, err := http.NewRequest(method, location.String(), body)
+		if err != nil {
+			return nil, nil, err
+		}
+
+		req.Header = header
+
+		intermediateConn, err = dialer.Dial(req)
+		if err != nil {
+			return nil, nil, err
+		}
+
+		// Peek at the backend response.
+		rawResponse.Reset()
+		respReader := bufio.NewReader(io.TeeReader(
+			io.LimitReader(intermediateConn, maxResponseSize), // Don't read more than maxResponseSize bytes.
+			rawResponse)) // Save the raw response.
+		resp, err := http.ReadResponse(respReader, nil)
+		if err != nil {
+			// Unable to read the backend response; let the client handle it.
+			klog.Warningf("Error reading backend response: %v", err)
+			break redirectLoop
+		}
+
+		switch resp.StatusCode {
+		case http.StatusFound:
+			// Redirect, continue.
+		default:
+			// Don't redirect.
+			break redirectLoop
+		}
+
+		// Redirected requests switch to "GET" according to the HTTP spec:
+		// https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3
+		method = "GET"
+		// don't send a body when following redirects
+		body = nil
+
+		resp.Body.Close() // not used
+
+		// Prepare to follow the redirect.
+		redirectStr := resp.Header.Get("Location")
+		if redirectStr == "" {
+			return nil, nil, fmt.Errorf("%d response missing Location header", resp.StatusCode)
+		}
+		// We have to parse relative to the current location, NOT originalLocation. For example,
+		// if we request http://foo.com/a and get back "http://bar.com/b", the result should be
+		// http://bar.com/b. If we then make that request and get back a redirect to "/c", the result
+		// should be http://bar.com/c, not http://foo.com/c.
+		location, err = location.Parse(redirectStr)
+		if err != nil {
+			return nil, nil, fmt.Errorf("malformed Location header: %v", err)
+		}
+
+		// Only follow redirects to the same host. Otherwise, propagate the redirect response back.
+		if requireSameHostRedirects && location.Hostname() != originalLocation.Hostname() {
+			break redirectLoop
+		}
+
+		// Reset the connection.
+		intermediateConn.Close()
+		intermediateConn = nil
+	}
+
+	connToReturn := intermediateConn
+	intermediateConn = nil // Don't close the connection when we return it.
+	return connToReturn, rawResponse.Bytes(), nil
+}
+
+// CloneRequest creates a shallow copy of the request along with a deep copy of the Headers.
+func CloneRequest(req *http.Request) *http.Request {
+	r := new(http.Request)
+
+	// shallow clone
+	*r = *req
+
+	// deep copy headers
+	r.Header = CloneHeader(req.Header)
+
+	return r
+}
+
+// CloneHeader creates a deep copy of an http.Header.
+func CloneHeader(in http.Header) http.Header {
+	out := make(http.Header, len(in))
+	for key, values := range in {
+		newValues := make([]string, len(values))
+		copy(newValues, values)
+		out[key] = newValues
+	}
+	return out
+}

vendor/k8s.io/apimachinery/pkg/util/net/interface.go

@@ -0,0 +1,416 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"bufio"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"net"
+	"os"
+
+	"strings"
+
+	"k8s.io/klog"
+)
+
+type AddressFamily uint
+
+const (
+	familyIPv4 AddressFamily = 4
+	familyIPv6 AddressFamily = 6
+)
+
+const (
+	ipv4RouteFile = "/proc/net/route"
+	ipv6RouteFile = "/proc/net/ipv6_route"
+)
+
+type Route struct {
+	Interface   string
+	Destination net.IP
+	Gateway     net.IP
+	Family      AddressFamily
+}
+
+type RouteFile struct {
+	name  string
+	parse func(input io.Reader) ([]Route, error)
+}
+
+// noRoutesError can be returned by ChooseBindAddress() in case of no routes
+type noRoutesError struct {
+	message string
+}
+
+func (e noRoutesError) Error() string {
+	return e.message
+}
+
+// IsNoRoutesError checks if an error is of type noRoutesError
+func IsNoRoutesError(err error) bool {
+	if err == nil {
+		return false
+	}
+	switch err.(type) {
+	case noRoutesError:
+		return true
+	default:
+		return false
+	}
+}
+
+var (
+	v4File = RouteFile{name: ipv4RouteFile, parse: getIPv4DefaultRoutes}
+	v6File = RouteFile{name: ipv6RouteFile, parse: getIPv6DefaultRoutes}
+)
+
+func (rf RouteFile) extract() ([]Route, error) {
+	file, err := os.Open(rf.name)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	return rf.parse(file)
+}
+
+// getIPv4DefaultRoutes obtains the IPv4 routes, and filters out non-default routes.
+func getIPv4DefaultRoutes(input io.Reader) ([]Route, error) {
+	routes := []Route{}
+	scanner := bufio.NewReader(input)
+	for {
+		line, err := scanner.ReadString('\n')
+		if err == io.EOF {
+			break
+		}
+		//ignore the headers in the route info
+		if strings.HasPrefix(line, "Iface") {
+			continue
+		}
+		fields := strings.Fields(line)
+		// Interested in fields:
+		//  0 - interface name
+		//  1 - destination address
+		//  2 - gateway
+		dest, err := parseIP(fields[1], familyIPv4)
+		if err != nil {
+			return nil, err
+		}
+		gw, err := parseIP(fields[2], familyIPv4)
+		if err != nil {
+			return nil, err
+		}
+		if !dest.Equal(net.IPv4zero) {
+			continue
+		}
+		routes = append(routes, Route{
+			Interface:   fields[0],
+			Destination: dest,
+			Gateway:     gw,
+			Family:      familyIPv4,
+		})
+	}
+	return routes, nil
+}
+
+func getIPv6DefaultRoutes(input io.Reader) ([]Route, error) {
+	routes := []Route{}
+	scanner := bufio.NewReader(input)
+	for {
+		line, err := scanner.ReadString('\n')
+		if err == io.EOF {
+			break
+		}
+		fields := strings.Fields(line)
+		// Interested in fields:
+		//  0 - destination address
+		//  4 - gateway
+		//  9 - interface name
+		dest, err := parseIP(fields[0], familyIPv6)
+		if err != nil {
+			return nil, err
+		}
+		gw, err := parseIP(fields[4], familyIPv6)
+		if err != nil {
+			return nil, err
+		}
+		if !dest.Equal(net.IPv6zero) {
+			continue
+		}
+		if gw.Equal(net.IPv6zero) {
+			continue // loopback
+		}
+		routes = append(routes, Route{
+			Interface:   fields[9],
+			Destination: dest,
+			Gateway:     gw,
+			Family:      familyIPv6,
+		})
+	}
+	return routes, nil
+}
+
+// parseIP takes the hex IP address string from route file and converts it
+// to a net.IP address. For IPv4, the value must be converted to big endian.
+func parseIP(str string, family AddressFamily) (net.IP, error) {
+	if str == "" {
+		return nil, fmt.Errorf("input is nil")
+	}
+	bytes, err := hex.DecodeString(str)
+	if err != nil {
+		return nil, err
+	}
+	if family == familyIPv4 {
+		if len(bytes) != net.IPv4len {
+			return nil, fmt.Errorf("invalid IPv4 address in route")
+		}
+		return net.IP([]byte{bytes[3], bytes[2], bytes[1], bytes[0]}), nil
+	}
+	// Must be IPv6
+	if len(bytes) != net.IPv6len {
+		return nil, fmt.Errorf("invalid IPv6 address in route")
+	}
+	return net.IP(bytes), nil
+}
+
+func isInterfaceUp(intf *net.Interface) bool {
+	if intf == nil {
+		return false
+	}
+	if intf.Flags&net.FlagUp != 0 {
+		klog.V(4).Infof("Interface %v is up", intf.Name)
+		return true
+	}
+	return false
+}
+
+func isLoopbackOrPointToPoint(intf *net.Interface) bool {
+	return intf.Flags&(net.FlagLoopback|net.FlagPointToPoint) != 0
+}
+
+// getMatchingGlobalIP returns the first valid global unicast address of the given
+// 'family' from the list of 'addrs'.
+func getMatchingGlobalIP(addrs []net.Addr, family AddressFamily) (net.IP, error) {
+	if len(addrs) > 0 {
+		for i := range addrs {
+			klog.V(4).Infof("Checking addr  %s.", addrs[i].String())
+			ip, _, err := net.ParseCIDR(addrs[i].String())
+			if err != nil {
+				return nil, err
+			}
+			if memberOf(ip, family) {
+				if ip.IsGlobalUnicast() {
+					klog.V(4).Infof("IP found %v", ip)
+					return ip, nil
+				} else {
+					klog.V(4).Infof("Non-global unicast address found %v", ip)
+				}
+			} else {
+				klog.V(4).Infof("%v is not an IPv%d address", ip, int(family))
+			}
+
+		}
+	}
+	return nil, nil
+}
+
+// getIPFromInterface gets the IPs on an interface and returns a global unicast address, if any. The
+// interface must be up, the IP must in the family requested, and the IP must be a global unicast address.
+func getIPFromInterface(intfName string, forFamily AddressFamily, nw networkInterfacer) (net.IP, error) {
+	intf, err := nw.InterfaceByName(intfName)
+	if err != nil {
+		return nil, err
+	}
+	if isInterfaceUp(intf) {
+		addrs, err := nw.Addrs(intf)
+		if err != nil {
+			return nil, err
+		}
+		klog.V(4).Infof("Interface %q has %d addresses :%v.", intfName, len(addrs), addrs)
+		matchingIP, err := getMatchingGlobalIP(addrs, forFamily)
+		if err != nil {
+			return nil, err
+		}
+		if matchingIP != nil {
+			klog.V(4).Infof("Found valid IPv%d address %v for interface %q.", int(forFamily), matchingIP, intfName)
+			return matchingIP, nil
+		}
+	}
+	return nil, nil
+}
+
+// memberOF tells if the IP is of the desired family. Used for checking interface addresses.
+func memberOf(ip net.IP, family AddressFamily) bool {
+	if ip.To4() != nil {
+		return family == familyIPv4
+	} else {
+		return family == familyIPv6
+	}
+}
+
+// chooseIPFromHostInterfaces looks at all system interfaces, trying to find one that is up that
+// has a global unicast address (non-loopback, non-link local, non-point2point), and returns the IP.
+// Searches for IPv4 addresses, and then IPv6 addresses.
+func chooseIPFromHostInterfaces(nw networkInterfacer) (net.IP, error) {
+	intfs, err := nw.Interfaces()
+	if err != nil {
+		return nil, err
+	}
+	if len(intfs) == 0 {
+		return nil, fmt.Errorf("no interfaces found on host.")
+	}
+	for _, family := range []AddressFamily{familyIPv4, familyIPv6} {
+		klog.V(4).Infof("Looking for system interface with a global IPv%d address", uint(family))
+		for _, intf := range intfs {
+			if !isInterfaceUp(&intf) {
+				klog.V(4).Infof("Skipping: down interface %q", intf.Name)
+				continue
+			}
+			if isLoopbackOrPointToPoint(&intf) {
+				klog.V(4).Infof("Skipping: LB or P2P interface %q", intf.Name)
+				continue
+			}
+			addrs, err := nw.Addrs(&intf)
+			if err != nil {
+				return nil, err
+			}
+			if len(addrs) == 0 {
+				klog.V(4).Infof("Skipping: no addresses on interface %q", intf.Name)
+				continue
+			}
+			for _, addr := range addrs {
+				ip, _, err := net.ParseCIDR(addr.String())
+				if err != nil {
+					return nil, fmt.Errorf("Unable to parse CIDR for interface %q: %s", intf.Name, err)
+				}
+				if !memberOf(ip, family) {
+					klog.V(4).Infof("Skipping: no address family match for %q on interface %q.", ip, intf.Name)
+					continue
+				}
+				// TODO: Decide if should open up to allow IPv6 LLAs in future.
+				if !ip.IsGlobalUnicast() {
+					klog.V(4).Infof("Skipping: non-global address %q on interface %q.", ip, intf.Name)
+					continue
+				}
+				klog.V(4).Infof("Found global unicast address %q on interface %q.", ip, intf.Name)
+				return ip, nil
+			}
+		}
+	}
+	return nil, fmt.Errorf("no acceptable interface with global unicast address found on host")
+}
+
+// ChooseHostInterface is a method used fetch an IP for a daemon.
+// If there is no routing info file, it will choose a global IP from the system
+// interfaces. Otherwise, it will use IPv4 and IPv6 route information to return the
+// IP of the interface with a gateway on it (with priority given to IPv4). For a node
+// with no internet connection, it returns error.
+func ChooseHostInterface() (net.IP, error) {
+	var nw networkInterfacer = networkInterface{}
+	if _, err := os.Stat(ipv4RouteFile); os.IsNotExist(err) {
+		return chooseIPFromHostInterfaces(nw)
+	}
+	routes, err := getAllDefaultRoutes()
+	if err != nil {
+		return nil, err
+	}
+	return chooseHostInterfaceFromRoute(routes, nw)
+}
+
+// networkInterfacer defines an interface for several net library functions. Production
+// code will forward to net library functions, and unit tests will override the methods
+// for testing purposes.
+type networkInterfacer interface {
+	InterfaceByName(intfName string) (*net.Interface, error)
+	Addrs(intf *net.Interface) ([]net.Addr, error)
+	Interfaces() ([]net.Interface, error)
+}
+
+// networkInterface implements the networkInterfacer interface for production code, just
+// wrapping the underlying net library function calls.
+type networkInterface struct{}
+
+func (_ networkInterface) InterfaceByName(intfName string) (*net.Interface, error) {
+	return net.InterfaceByName(intfName)
+}
+
+func (_ networkInterface) Addrs(intf *net.Interface) ([]net.Addr, error) {
+	return intf.Addrs()
+}
+
+func (_ networkInterface) Interfaces() ([]net.Interface, error) {
+	return net.Interfaces()
+}
+
+// getAllDefaultRoutes obtains IPv4 and IPv6 default routes on the node. If unable
+// to read the IPv4 routing info file, we return an error. If unable to read the IPv6
+// routing info file (which is optional), we'll just use the IPv4 route information.
+// Using all the routing info, if no default routes are found, an error is returned.
+func getAllDefaultRoutes() ([]Route, error) {
+	routes, err := v4File.extract()
+	if err != nil {
+		return nil, err
+	}
+	v6Routes, _ := v6File.extract()
+	routes = append(routes, v6Routes...)
+	if len(routes) == 0 {
+		return nil, noRoutesError{
+			message: fmt.Sprintf("no default routes found in %q or %q", v4File.name, v6File.name),
+		}
+	}
+	return routes, nil
+}
+
+// chooseHostInterfaceFromRoute cycles through each default route provided, looking for a
+// global IP address from the interface for the route. Will first look all each IPv4 route for
+// an IPv4 IP, and then will look at each IPv6 route for an IPv6 IP.
+func chooseHostInterfaceFromRoute(routes []Route, nw networkInterfacer) (net.IP, error) {
+	for _, family := range []AddressFamily{familyIPv4, familyIPv6} {
+		klog.V(4).Infof("Looking for default routes with IPv%d addresses", uint(family))
+		for _, route := range routes {
+			if route.Family != family {
+				continue
+			}
+			klog.V(4).Infof("Default route transits interface %q", route.Interface)
+			finalIP, err := getIPFromInterface(route.Interface, family, nw)
+			if err != nil {
+				return nil, err
+			}
+			if finalIP != nil {
+				klog.V(4).Infof("Found active IP %v ", finalIP)
+				return finalIP, nil
+			}
+		}
+	}
+	klog.V(4).Infof("No active IP found by looking at default routes")
+	return nil, fmt.Errorf("unable to select an IP from default routes.")
+}
+
+// If bind-address is usable, return it directly
+// If bind-address is not usable (unset, 0.0.0.0, or loopback), we will use the host's default
+// interface.
+func ChooseBindAddress(bindAddress net.IP) (net.IP, error) {
+	if bindAddress == nil || bindAddress.IsUnspecified() || bindAddress.IsLoopback() {
+		hostIP, err := ChooseHostInterface()
+		if err != nil {
+			return nil, err
+		}
+		bindAddress = hostIP
+	}
+	return bindAddress, nil
+}

vendor/k8s.io/apimachinery/pkg/util/net/port_range.go

@@ -0,0 +1,149 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// PortRange represents a range of TCP/UDP ports.  To represent a single port,
+// set Size to 1.
+type PortRange struct {
+	Base int
+	Size int
+}
+
+// Contains tests whether a given port falls within the PortRange.
+func (pr *PortRange) Contains(p int) bool {
+	return (p >= pr.Base) && ((p - pr.Base) < pr.Size)
+}
+
+// String converts the PortRange to a string representation, which can be
+// parsed by PortRange.Set or ParsePortRange.
+func (pr PortRange) String() string {
+	if pr.Size == 0 {
+		return ""
+	}
+	return fmt.Sprintf("%d-%d", pr.Base, pr.Base+pr.Size-1)
+}
+
+// Set parses a string of the form "value", "min-max", or "min+offset", inclusive at both ends, and
+// sets the PortRange from it.  This is part of the flag.Value and pflag.Value
+// interfaces.
+func (pr *PortRange) Set(value string) error {
+	const (
+		SinglePortNotation = 1 << iota
+		HyphenNotation
+		PlusNotation
+	)
+
+	value = strings.TrimSpace(value)
+	hyphenIndex := strings.Index(value, "-")
+	plusIndex := strings.Index(value, "+")
+
+	if value == "" {
+		pr.Base = 0
+		pr.Size = 0
+		return nil
+	}
+
+	var err error
+	var low, high int
+	var notation int
+
+	if plusIndex == -1 && hyphenIndex == -1 {
+		notation |= SinglePortNotation
+	}
+	if hyphenIndex != -1 {
+		notation |= HyphenNotation
+	}
+	if plusIndex != -1 {
+		notation |= PlusNotation
+	}
+
+	switch notation {
+	case SinglePortNotation:
+		var port int
+		port, err = strconv.Atoi(value)
+		if err != nil {
+			return err
+		}
+		low = port
+		high = port
+	case HyphenNotation:
+		low, err = strconv.Atoi(value[:hyphenIndex])
+		if err != nil {
+			return err
+		}
+		high, err = strconv.Atoi(value[hyphenIndex+1:])
+		if err != nil {
+			return err
+		}
+	case PlusNotation:
+		var offset int
+		low, err = strconv.Atoi(value[:plusIndex])
+		if err != nil {
+			return err
+		}
+		offset, err = strconv.Atoi(value[plusIndex+1:])
+		if err != nil {
+			return err
+		}
+		high = low + offset
+	default:
+		return fmt.Errorf("unable to parse port range: %s", value)
+	}
+
+	if low > 65535 || high > 65535 {
+		return fmt.Errorf("the port range cannot be greater than 65535: %s", value)
+	}
+
+	if high < low {
+		return fmt.Errorf("end port cannot be less than start port: %s", value)
+	}
+
+	pr.Base = low
+	pr.Size = 1 + high - low
+	return nil
+}
+
+// Type returns a descriptive string about this type.  This is part of the
+// pflag.Value interface.
+func (*PortRange) Type() string {
+	return "portRange"
+}
+
+// ParsePortRange parses a string of the form "min-max", inclusive at both
+// ends, and initializs a new PortRange from it.
+func ParsePortRange(value string) (*PortRange, error) {
+	pr := &PortRange{}
+	err := pr.Set(value)
+	if err != nil {
+		return nil, err
+	}
+	return pr, nil
+}
+
+func ParsePortRangeOrDie(value string) *PortRange {
+	pr, err := ParsePortRange(value)
+	if err != nil {
+		panic(fmt.Sprintf("couldn't parse port range %q: %v", value, err))
+	}
+	return pr
+}

vendor/k8s.io/apimachinery/pkg/util/net/port_split.go

@@ -0,0 +1,77 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"strings"
+
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+var validSchemes = sets.NewString("http", "https", "")
+
+// SplitSchemeNamePort takes a string of the following forms:
+//  * "<name>",                 returns "",        "<name>","",      true
+//  * "<name>:<port>",          returns "",        "<name>","<port>",true
+//  * "<scheme>:<name>:<port>", returns "<scheme>","<name>","<port>",true
+//
+// Name must be non-empty or valid will be returned false.
+// Scheme must be "http" or "https" if specified
+// Port is returned as a string, and it is not required to be numeric (could be
+// used for a named port, for example).
+func SplitSchemeNamePort(id string) (scheme, name, port string, valid bool) {
+	parts := strings.Split(id, ":")
+	switch len(parts) {
+	case 1:
+		name = parts[0]
+	case 2:
+		name = parts[0]
+		port = parts[1]
+	case 3:
+		scheme = parts[0]
+		name = parts[1]
+		port = parts[2]
+	default:
+		return "", "", "", false
+	}
+
+	if len(name) > 0 && validSchemes.Has(scheme) {
+		return scheme, name, port, true
+	} else {
+		return "", "", "", false
+	}
+}
+
+// JoinSchemeNamePort returns a string that specifies the scheme, name, and port:
+//  * "<name>"
+//  * "<name>:<port>"
+//  * "<scheme>:<name>:<port>"
+// None of the parameters may contain a ':' character
+// Name is required
+// Scheme must be "", "http", or "https"
+func JoinSchemeNamePort(scheme, name, port string) string {
+	if len(scheme) > 0 {
+		// Must include three segments to specify scheme
+		return scheme + ":" + name + ":" + port
+	}
+	if len(port) > 0 {
+		// Must include two segments to specify port
+		return name + ":" + port
+	}
+	// Return name alone
+	return name
+}

vendor/k8s.io/apimachinery/pkg/util/net/util.go

@@ -0,0 +1,56 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"net"
+	"net/url"
+	"os"
+	"reflect"
+	"syscall"
+)
+
+// IPNetEqual checks if the two input IPNets are representing the same subnet.
+// For example,
+//	10.0.0.1/24 and 10.0.0.0/24 are the same subnet.
+//	10.0.0.1/24 and 10.0.0.0/25 are not the same subnet.
+func IPNetEqual(ipnet1, ipnet2 *net.IPNet) bool {
+	if ipnet1 == nil || ipnet2 == nil {
+		return false
+	}
+	if reflect.DeepEqual(ipnet1.Mask, ipnet2.Mask) && ipnet1.Contains(ipnet2.IP) && ipnet2.Contains(ipnet1.IP) {
+		return true
+	}
+	return false
+}
+
+// Returns if the given err is "connection reset by peer" error.
+func IsConnectionReset(err error) bool {
+	if urlErr, ok := err.(*url.Error); ok {
+		err = urlErr.Err
+	}
+	if opErr, ok := err.(*net.OpError); ok {
+		err = opErr.Err
+	}
+	if osErr, ok := err.(*os.SyscallError); ok {
+		err = osErr.Err
+	}
+	if errno, ok := err.(syscall.Errno); ok && errno == syscall.ECONNRESET {
+		return true
+	}
+	return false
+}