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Commit 78d2fda4 authored by BenTheElder's avatar BenTheElder
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Move proxySocket out of proxier.go to proxysocket.go

Moves proxySocket out of proxier.go to new proxysocket.go in proxy package in order to start separating proxy logic and implementation and make proxier more manageable to review.
parent c50f9061
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Showing with 282 additions and 252 deletions
pkg/proxy/proxier.go
View file @ 78d2fda4
......@@ -18,7 +18,6 @@ package proxy
import (
"fmt"
"io"
"net"
"strconv"
"strings"
......@@ -46,234 +45,6 @@ type serviceInfo struct {
stickyMaxAgeMinutes int
}
// How long we wait for a connection to a backend in seconds
var endpointDialTimeout = []time.Duration{1, 2, 4, 8}
// Abstraction over TCP/UDP sockets which are proxied.
type proxySocket interface {
// Addr gets the net.Addr for a proxySocket.
Addr() net.Addr
// Close stops the proxySocket from accepting incoming connections.
// Each implementation should comment on the impact of calling Close
// while sessions are active.
Close() error
// ProxyLoop proxies incoming connections for the specified service to the service endpoints.
ProxyLoop(service ServicePortName, info *serviceInfo, proxier *Proxier)
}
// tcpProxySocket implements proxySocket. Close() is implemented by net.Listener. When Close() is called,
// no new connections are allowed but existing connections are left untouched.
type tcpProxySocket struct {
net.Listener
}
func tryConnect(service ServicePortName, srcAddr net.Addr, protocol string, proxier *Proxier) (out net.Conn, err error) {
for _, retryTimeout := range endpointDialTimeout {
endpoint, err := proxier.loadBalancer.NextEndpoint(service, srcAddr)
if err != nil {
glog.Errorf("Couldn't find an endpoint for %s: %v", service, err)
return nil, err
}
glog.V(3).Infof("Mapped service %q to endpoint %s", service, endpoint)
// TODO: This could spin up a new goroutine to make the outbound connection,
// and keep accepting inbound traffic.
outConn, err := net.DialTimeout(protocol, endpoint, retryTimeout*time.Second)
if err != nil {
if isTooManyFDsError(err) {
panic("Dial failed: " + err.Error())
}
glog.Errorf("Dial failed: %v", err)
continue
}
return outConn, nil
}
return nil, fmt.Errorf("failed to connect to an endpoint.")
}
func (tcp *tcpProxySocket) ProxyLoop(service ServicePortName, myInfo *serviceInfo, proxier *Proxier) {
for {
if info, exists := proxier.getServiceInfo(service); !exists || info != myInfo {
// The service port was closed or replaced.
return
}
// Block until a connection is made.
inConn, err := tcp.Accept()
if err != nil {
if isTooManyFDsError(err) {
panic("Accept failed: " + err.Error())
}
if isClosedError(err) {
return
}
if info, exists := proxier.getServiceInfo(service); !exists || info != myInfo {
// Then the service port was just closed so the accept failure is to be expected.
return
}
glog.Errorf("Accept failed: %v", err)
continue
}
glog.V(2).Infof("Accepted TCP connection from %v to %v", inConn.RemoteAddr(), inConn.LocalAddr())
outConn, err := tryConnect(service, inConn.(*net.TCPConn).RemoteAddr(), "tcp", proxier)
if err != nil {
glog.Errorf("Failed to connect to balancer: %v", err)
inConn.Close()
continue
}
// Spin up an async copy loop.
go proxyTCP(inConn.(*net.TCPConn), outConn.(*net.TCPConn))
}
}
// proxyTCP proxies data bi-directionally between in and out.
func proxyTCP(in, out *net.TCPConn) {
var wg sync.WaitGroup
wg.Add(2)
glog.V(4).Infof("Creating proxy between %v <-> %v <-> %v <-> %v",
in.RemoteAddr(), in.LocalAddr(), out.LocalAddr(), out.RemoteAddr())
go copyBytes("from backend", in, out, &wg)
go copyBytes("to backend", out, in, &wg)
wg.Wait()
in.Close()
out.Close()
}
func copyBytes(direction string, dest, src *net.TCPConn, wg *sync.WaitGroup) {
defer wg.Done()
glog.V(4).Infof("Copying %s: %s -> %s", direction, src.RemoteAddr(), dest.RemoteAddr())
n, err := io.Copy(dest, src)
if err != nil {
glog.Errorf("I/O error: %v", err)
}
glog.V(4).Infof("Copied %d bytes %s: %s -> %s", n, direction, src.RemoteAddr(), dest.RemoteAddr())
dest.CloseWrite()
src.CloseRead()
}
// udpProxySocket implements proxySocket. Close() is implemented by net.UDPConn. When Close() is called,
// no new connections are allowed and existing connections are broken.
// TODO: We could lame-duck this ourselves, if it becomes important.
type udpProxySocket struct {
*net.UDPConn
}
func (udp *udpProxySocket) Addr() net.Addr {
return udp.LocalAddr()
}
// Holds all the known UDP clients that have not timed out.
type clientCache struct {
mu sync.Mutex
clients map[string]net.Conn // addr string -> connection
}
func newClientCache() *clientCache {
return &clientCache{clients: map[string]net.Conn{}}
}
func (udp *udpProxySocket) ProxyLoop(service ServicePortName, myInfo *serviceInfo, proxier *Proxier) {
activeClients := newClientCache()
var buffer [4096]byte // 4KiB should be enough for most whole-packets
for {
if info, exists := proxier.getServiceInfo(service); !exists || info != myInfo {
// The service port was closed or replaced.
break
}
// Block until data arrives.
// TODO: Accumulate a histogram of n or something, to fine tune the buffer size.
n, cliAddr, err := udp.ReadFrom(buffer[0:])
if err != nil {
if e, ok := err.(net.Error); ok {
if e.Temporary() {
glog.V(1).Infof("ReadFrom had a temporary failure: %v", err)
continue
}
}
glog.Errorf("ReadFrom failed, exiting ProxyLoop: %v", err)
break
}
// If this is a client we know already, reuse the connection and goroutine.
svrConn, err := udp.getBackendConn(activeClients, cliAddr, proxier, service, myInfo.timeout)
if err != nil {
continue
}
// TODO: It would be nice to let the goroutine handle this write, but we don't
// really want to copy the buffer. We could do a pool of buffers or something.
_, err = svrConn.Write(buffer[0:n])
if err != nil {
if !logTimeout(err) {
glog.Errorf("Write failed: %v", err)
// TODO: Maybe tear down the goroutine for this client/server pair?
}
continue
}
err = svrConn.SetDeadline(time.Now().Add(myInfo.timeout))
if err != nil {
glog.Errorf("SetDeadline failed: %v", err)
continue
}
}
}
func (udp *udpProxySocket) getBackendConn(activeClients *clientCache, cliAddr net.Addr, proxier *Proxier, service ServicePortName, timeout time.Duration) (net.Conn, error) {
activeClients.mu.Lock()
defer activeClients.mu.Unlock()
svrConn, found := activeClients.clients[cliAddr.String()]
if !found {
// TODO: This could spin up a new goroutine to make the outbound connection,
// and keep accepting inbound traffic.
glog.V(2).Infof("New UDP connection from %s", cliAddr)
var err error
svrConn, err = tryConnect(service, cliAddr, "udp", proxier)
if err != nil {
return nil, err
}
if err = svrConn.SetDeadline(time.Now().Add(timeout)); err != nil {
glog.Errorf("SetDeadline failed: %v", err)
return nil, err
}
activeClients.clients[cliAddr.String()] = svrConn
go func(cliAddr net.Addr, svrConn net.Conn, activeClients *clientCache, timeout time.Duration) {
defer util.HandleCrash()
udp.proxyClient(cliAddr, svrConn, activeClients, timeout)
}(cliAddr, svrConn, activeClients, timeout)
}
return svrConn, nil
}
// This function is expected to be called as a goroutine.
// TODO: Track and log bytes copied, like TCP
func (udp *udpProxySocket) proxyClient(cliAddr net.Addr, svrConn net.Conn, activeClients *clientCache, timeout time.Duration) {
defer svrConn.Close()
var buffer [4096]byte
for {
n, err := svrConn.Read(buffer[0:])
if err != nil {
if !logTimeout(err) {
glog.Errorf("Read failed: %v", err)
}
break
}
err = svrConn.SetDeadline(time.Now().Add(timeout))
if err != nil {
glog.Errorf("SetDeadline failed: %v", err)
break
}
n, err = udp.WriteTo(buffer[0:n], cliAddr)
if err != nil {
if !logTimeout(err) {
glog.Errorf("WriteTo failed: %v", err)
}
break
}
}
activeClients.mu.Lock()
delete(activeClients.clients, cliAddr.String())
activeClients.mu.Unlock()
}
func logTimeout(err error) bool {
if e, ok := err.(net.Error); ok {
if e.Timeout() {
......@@ -284,29 +55,6 @@ func logTimeout(err error) bool {
return false
}
func newProxySocket(protocol api.Protocol, ip net.IP, port int) (proxySocket, error) {
host := ip.String()
switch strings.ToUpper(string(protocol)) {
case "TCP":
listener, err := net.Listen("tcp", net.JoinHostPort(host, strconv.Itoa(port)))
if err != nil {
return nil, err
}
return &tcpProxySocket{listener}, nil
case "UDP":
addr, err := net.ResolveUDPAddr("udp", net.JoinHostPort(host, strconv.Itoa(port)))
if err != nil {
return nil, err
}
conn, err := net.ListenUDP("udp", addr)
if err != nil {
return nil, err
}
return &udpProxySocket{conn}, nil
}
return nil, fmt.Errorf("unknown protocol %q", protocol)
}
// Proxier is a simple proxy for TCP connections between a localhost:lport
// and services that provide the actual implementations.
type Proxier struct {
......
pkg/proxy/proxysocket.go 0 → 100644
View file @ 78d2fda4
/*
Copyright 2014 The Kubernetes Authors All rights reserved.
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 proxy
import (
"fmt"
"io"
"net"
"strconv"
"strings"
"sync"
"time"
"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
"github.com/golang/glog"
)
// Abstraction over TCP/UDP sockets which are proxied.
type proxySocket interface {
// Addr gets the net.Addr for a proxySocket.
Addr() net.Addr
// Close stops the proxySocket from accepting incoming connections.
// Each implementation should comment on the impact of calling Close
// while sessions are active.
Close() error
// ProxyLoop proxies incoming connections for the specified service to the service endpoints.
ProxyLoop(service ServicePortName, info *serviceInfo, proxier *Proxier)
}
func newProxySocket(protocol api.Protocol, ip net.IP, port int) (proxySocket, error) {
host := ip.String()
switch strings.ToUpper(string(protocol)) {
case "TCP":
listener, err := net.Listen("tcp", net.JoinHostPort(host, strconv.Itoa(port)))
if err != nil {
return nil, err
}
return &tcpProxySocket{listener}, nil
case "UDP":
addr, err := net.ResolveUDPAddr("udp", net.JoinHostPort(host, strconv.Itoa(port)))
if err != nil {
return nil, err
}
conn, err := net.ListenUDP("udp", addr)
if err != nil {
return nil, err
}
return &udpProxySocket{conn}, nil
}
return nil, fmt.Errorf("unknown protocol %q", protocol)
}
// How long we wait for a connection to a backend in seconds
var endpointDialTimeout = []time.Duration{1, 2, 4, 8}
// tcpProxySocket implements proxySocket. Close() is implemented by net.Listener. When Close() is called,
// no new connections are allowed but existing connections are left untouched.
type tcpProxySocket struct {
net.Listener
}
func tryConnect(service ServicePortName, srcAddr net.Addr, protocol string, proxier *Proxier) (out net.Conn, err error) {
for _, retryTimeout := range endpointDialTimeout {
endpoint, err := proxier.loadBalancer.NextEndpoint(service, srcAddr)
if err != nil {
glog.Errorf("Couldn't find an endpoint for %s: %v", service, err)
return nil, err
}
glog.V(3).Infof("Mapped service %q to endpoint %s", service, endpoint)
// TODO: This could spin up a new goroutine to make the outbound connection,
// and keep accepting inbound traffic.
outConn, err := net.DialTimeout(protocol, endpoint, retryTimeout*time.Second)
if err != nil {
if isTooManyFDsError(err) {
panic("Dial failed: " + err.Error())
}
glog.Errorf("Dial failed: %v", err)
continue
}
return outConn, nil
}
return nil, fmt.Errorf("failed to connect to an endpoint.")
}
func (tcp *tcpProxySocket) ProxyLoop(service ServicePortName, myInfo *serviceInfo, proxier *Proxier) {
for {
if info, exists := proxier.getServiceInfo(service); !exists || info != myInfo {
// The service port was closed or replaced.
return
}
// Block until a connection is made.
inConn, err := tcp.Accept()
if err != nil {
if isTooManyFDsError(err) {
panic("Accept failed: " + err.Error())
}
if isClosedError(err) {
return
}
if info, exists := proxier.getServiceInfo(service); !exists || info != myInfo {
// Then the service port was just closed so the accept failure is to be expected.
return
}
glog.Errorf("Accept failed: %v", err)
continue
}
glog.V(2).Infof("Accepted TCP connection from %v to %v", inConn.RemoteAddr(), inConn.LocalAddr())
outConn, err := tryConnect(service, inConn.(*net.TCPConn).RemoteAddr(), "tcp", proxier)
if err != nil {
glog.Errorf("Failed to connect to balancer: %v", err)
inConn.Close()
continue
}
// Spin up an async copy loop.
go proxyTCP(inConn.(*net.TCPConn), outConn.(*net.TCPConn))
}
}
// proxyTCP proxies data bi-directionally between in and out.
func proxyTCP(in, out *net.TCPConn) {
var wg sync.WaitGroup
wg.Add(2)
glog.V(4).Infof("Creating proxy between %v <-> %v <-> %v <-> %v",
in.RemoteAddr(), in.LocalAddr(), out.LocalAddr(), out.RemoteAddr())
go copyBytes("from backend", in, out, &wg)
go copyBytes("to backend", out, in, &wg)
wg.Wait()
in.Close()
out.Close()
}
func copyBytes(direction string, dest, src *net.TCPConn, wg *sync.WaitGroup) {
defer wg.Done()
glog.V(4).Infof("Copying %s: %s -> %s", direction, src.RemoteAddr(), dest.RemoteAddr())
n, err := io.Copy(dest, src)
if err != nil {
glog.Errorf("I/O error: %v", err)
}
glog.V(4).Infof("Copied %d bytes %s: %s -> %s", n, direction, src.RemoteAddr(), dest.RemoteAddr())
dest.CloseWrite()
src.CloseRead()
}
// udpProxySocket implements proxySocket. Close() is implemented by net.UDPConn. When Close() is called,
// no new connections are allowed and existing connections are broken.
// TODO: We could lame-duck this ourselves, if it becomes important.
type udpProxySocket struct {
*net.UDPConn
}
func (udp *udpProxySocket) Addr() net.Addr {
return udp.LocalAddr()
}
// Holds all the known UDP clients that have not timed out.
type clientCache struct {
mu sync.Mutex
clients map[string]net.Conn // addr string -> connection
}
func newClientCache() *clientCache {
return &clientCache{clients: map[string]net.Conn{}}
}
func (udp *udpProxySocket) ProxyLoop(service ServicePortName, myInfo *serviceInfo, proxier *Proxier) {
activeClients := newClientCache()
var buffer [4096]byte // 4KiB should be enough for most whole-packets
for {
if info, exists := proxier.getServiceInfo(service); !exists || info != myInfo {
// The service port was closed or replaced.
break
}
// Block until data arrives.
// TODO: Accumulate a histogram of n or something, to fine tune the buffer size.
n, cliAddr, err := udp.ReadFrom(buffer[0:])
if err != nil {
if e, ok := err.(net.Error); ok {
if e.Temporary() {
glog.V(1).Infof("ReadFrom had a temporary failure: %v", err)
continue
}
}
glog.Errorf("ReadFrom failed, exiting ProxyLoop: %v", err)
break
}
// If this is a client we know already, reuse the connection and goroutine.
svrConn, err := udp.getBackendConn(activeClients, cliAddr, proxier, service, myInfo.timeout)
if err != nil {
continue
}
// TODO: It would be nice to let the goroutine handle this write, but we don't
// really want to copy the buffer. We could do a pool of buffers or something.
_, err = svrConn.Write(buffer[0:n])
if err != nil {
if !logTimeout(err) {
glog.Errorf("Write failed: %v", err)
// TODO: Maybe tear down the goroutine for this client/server pair?
}
continue
}
err = svrConn.SetDeadline(time.Now().Add(myInfo.timeout))
if err != nil {
glog.Errorf("SetDeadline failed: %v", err)
continue
}
}
}
func (udp *udpProxySocket) getBackendConn(activeClients *clientCache, cliAddr net.Addr, proxier *Proxier, service ServicePortName, timeout time.Duration) (net.Conn, error) {
activeClients.mu.Lock()
defer activeClients.mu.Unlock()
svrConn, found := activeClients.clients[cliAddr.String()]
if !found {
// TODO: This could spin up a new goroutine to make the outbound connection,
// and keep accepting inbound traffic.
glog.V(2).Infof("New UDP connection from %s", cliAddr)
var err error
svrConn, err = tryConnect(service, cliAddr, "udp", proxier)
if err != nil {
return nil, err
}
if err = svrConn.SetDeadline(time.Now().Add(timeout)); err != nil {
glog.Errorf("SetDeadline failed: %v", err)
return nil, err
}
activeClients.clients[cliAddr.String()] = svrConn
go func(cliAddr net.Addr, svrConn net.Conn, activeClients *clientCache, timeout time.Duration) {
defer util.HandleCrash()
udp.proxyClient(cliAddr, svrConn, activeClients, timeout)
}(cliAddr, svrConn, activeClients, timeout)
}
return svrConn, nil
}
// This function is expected to be called as a goroutine.
// TODO: Track and log bytes copied, like TCP
func (udp *udpProxySocket) proxyClient(cliAddr net.Addr, svrConn net.Conn, activeClients *clientCache, timeout time.Duration) {
defer svrConn.Close()
var buffer [4096]byte
for {
n, err := svrConn.Read(buffer[0:])
if err != nil {
if !logTimeout(err) {
glog.Errorf("Read failed: %v", err)
}
break
}
err = svrConn.SetDeadline(time.Now().Add(timeout))
if err != nil {
glog.Errorf("SetDeadline failed: %v", err)
break
}
n, err = udp.WriteTo(buffer[0:n], cliAddr)
if err != nil {
if !logTimeout(err) {
glog.Errorf("WriteTo failed: %v", err)
}
break
}
}
activeClients.mu.Lock()
delete(activeClients.clients, cliAddr.String())
activeClients.mu.Unlock()
}
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