зеркало из https://github.com/microsoft/docker.git
Network: Port mapping support.
Implemented a port allocator and a port mapper that is able to forward TCP ports from the host to the container.
This commit is contained in:
Andrea Luzzardi
Родитель
c7f4602b18
Коммит
799ffa1763
290
network.go
290
network.go
|
|
@ -5,20 +5,20 @@ import (
|
|||
"encoding/binary"
|
||||
"errors"
|
||||
"fmt"
|
||||
"log"
|
||||
"net"
|
||||
"os/exec"
|
||||
"strconv"
|
||||
"strings"
|
||||
)
|
||||
|
||||
const (
|
||||
networkBridgeIface = "lxcbr0"
|
||||
portRangeStart = 49153
|
||||
portRangeEnd = 65535
|
||||
)
|
||||
|
||||
type NetworkInterface struct {
|
||||
IPNet net.IPNet
|
||||
Gateway net.IP
|
||||
}
|
||||
|
||||
// IP utils
|
||||
|
||||
// Calculates the first and last IP addresses in an IPNet
|
||||
func networkRange(network *net.IPNet) (net.IP, net.IP) {
|
||||
netIP := network.IP.To4()
|
||||
firstIP := netIP.Mask(network.Mask)
|
||||
|
|
@ -29,6 +29,7 @@ func networkRange(network *net.IPNet) (net.IP, net.IP) {
|
|||
return firstIP, lastIP
|
||||
}
|
||||
|
||||
// Converts a 4 bytes IP into a 32 bit integer
|
||||
func ipToInt(ip net.IP) (int32, error) {
|
||||
buf := bytes.NewBuffer(ip.To4())
|
||||
var n int32
|
||||
|
|
@ -38,6 +39,7 @@ func ipToInt(ip net.IP) (int32, error) {
|
|||
return n, nil
|
||||
}
|
||||
|
||||
// Converts 32 bit integer into a 4 bytes IP address
|
||||
func intToIp(n int32) (net.IP, error) {
|
||||
var buf bytes.Buffer
|
||||
if err := binary.Write(&buf, binary.BigEndian, &n); err != nil {
|
||||
|
|
@ -50,6 +52,7 @@ func intToIp(n int32) (net.IP, error) {
|
|||
return ip, nil
|
||||
}
|
||||
|
||||
// Given a netmask, calculates the number of available hosts
|
||||
func networkSize(mask net.IPMask) (int32, error) {
|
||||
m := net.IPv4Mask(0, 0, 0, 0)
|
||||
for i := 0; i < net.IPv4len; i++ {
|
||||
|
|
@ -63,6 +66,15 @@ func networkSize(mask net.IPMask) (int32, error) {
|
|||
return n + 1, nil
|
||||
}
|
||||
|
||||
// Wrapper around the iptables command
|
||||
func iptables(args ...string) error {
|
||||
if err := exec.Command("/sbin/iptables", args...).Run(); err != nil {
|
||||
return fmt.Errorf("iptables failed: iptables %v", strings.Join(args, " "))
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Return the IPv4 address of a network interface
|
||||
func getIfaceAddr(name string) (net.Addr, error) {
|
||||
iface, err := net.InterfaceByName(name)
|
||||
if err != nil {
|
||||
|
|
@ -81,60 +93,122 @@ func getIfaceAddr(name string) (net.Addr, error) {
|
|||
}
|
||||
switch {
|
||||
case len(addrs4) == 0:
|
||||
return nil, fmt.Errorf("Bridge %v has no IP addresses", name)
|
||||
return nil, fmt.Errorf("Interface %v has no IP addresses", name)
|
||||
case len(addrs4) > 1:
|
||||
return nil, fmt.Errorf("Bridge %v has more than 1 IPv4 address", name)
|
||||
return nil, fmt.Errorf("Interface %v has more than 1 IPv4 address", name)
|
||||
}
|
||||
return addrs4[0], nil
|
||||
}
|
||||
|
||||
// Network allocator
|
||||
func newNetworkAllocator(iface string) (*NetworkAllocator, error) {
|
||||
addr, err := getIfaceAddr(iface)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
network := addr.(*net.IPNet)
|
||||
|
||||
alloc := &NetworkAllocator{
|
||||
iface: iface,
|
||||
net: network,
|
||||
}
|
||||
if err := alloc.populateFromNetwork(network); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return alloc, nil
|
||||
// Port mapper takes care of mapping external ports to containers by setting
|
||||
// up iptables rules.
|
||||
// It keeps track of all mappings and is able to unmap at will
|
||||
type PortMapper struct {
|
||||
mapping map[int]net.TCPAddr
|
||||
}
|
||||
|
||||
type NetworkAllocator struct {
|
||||
iface string
|
||||
net *net.IPNet
|
||||
queue chan (net.IP)
|
||||
func (mapper *PortMapper) cleanup() error {
|
||||
// Ignore errors - This could mean the chains were never set up
|
||||
iptables("-t", "nat", "-D", "PREROUTING", "-j", "DOCKER")
|
||||
iptables("-t", "nat", "-F", "DOCKER")
|
||||
iptables("-t", "nat", "-X", "DOCKER")
|
||||
mapper.mapping = make(map[int]net.TCPAddr)
|
||||
return nil
|
||||
}
|
||||
|
||||
func (alloc *NetworkAllocator) acquireIP() (net.IP, error) {
|
||||
select {
|
||||
case ip := <-alloc.queue:
|
||||
return ip, nil
|
||||
default:
|
||||
return net.IP{}, errors.New("No more IP addresses available")
|
||||
func (mapper *PortMapper) setup() error {
|
||||
if err := iptables("-t", "nat", "-N", "DOCKER"); err != nil {
|
||||
return errors.New("Unable to setup port networking: Failed to create DOCKER chain")
|
||||
}
|
||||
return net.IP{}, nil
|
||||
}
|
||||
|
||||
func (alloc *NetworkAllocator) releaseIP(ip net.IP) error {
|
||||
select {
|
||||
case alloc.queue <- ip:
|
||||
return nil
|
||||
default:
|
||||
return errors.New("Too many IP addresses have been released")
|
||||
if err := iptables("-t", "nat", "-A", "PREROUTING", "-j", "DOCKER"); err != nil {
|
||||
return errors.New("Unable to setup port networking: Failed to inject docker in PREROUTING chain")
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
func (alloc *NetworkAllocator) populateFromNetwork(network *net.IPNet) error {
|
||||
firstIP, _ := networkRange(network)
|
||||
size, err := networkSize(network.Mask)
|
||||
func (mapper *PortMapper) iptablesForward(rule string, port int, dest net.TCPAddr) error {
|
||||
return iptables("-t", "nat", rule, "DOCKER", "-p", "tcp", "--dport", strconv.Itoa(port),
|
||||
"-j", "DNAT", "--to-destination", net.JoinHostPort(dest.IP.String(), strconv.Itoa(dest.Port)))
|
||||
}
|
||||
|
||||
func (mapper *PortMapper) Map(port int, dest net.TCPAddr) error {
|
||||
if err := mapper.iptablesForward("-A", port, dest); err != nil {
|
||||
return err
|
||||
}
|
||||
mapper.mapping[port] = dest
|
||||
return nil
|
||||
}
|
||||
|
||||
func (mapper *PortMapper) Unmap(port int) error {
|
||||
dest, ok := mapper.mapping[port]
|
||||
if !ok {
|
||||
return errors.New("Port is not mapped")
|
||||
}
|
||||
if err := mapper.iptablesForward("-D", port, dest); err != nil {
|
||||
return err
|
||||
}
|
||||
delete(mapper.mapping, port)
|
||||
return nil
|
||||
}
|
||||
|
||||
func newPortMapper() (*PortMapper, error) {
|
||||
mapper := &PortMapper{}
|
||||
if err := mapper.cleanup(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if err := mapper.setup(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return mapper, nil
|
||||
}
|
||||
|
||||
// Port allocator: Atomatically allocate and release networking ports
|
||||
type PortAllocator struct {
|
||||
ports chan (int)
|
||||
}
|
||||
|
||||
func (alloc *PortAllocator) populate(start, end int) {
|
||||
alloc.ports = make(chan int, end-start)
|
||||
for port := start; port < end; port++ {
|
||||
alloc.ports <- port
|
||||
}
|
||||
}
|
||||
|
||||
func (alloc *PortAllocator) Acquire() (int, error) {
|
||||
select {
|
||||
case port := <-alloc.ports:
|
||||
return port, nil
|
||||
default:
|
||||
return -1, errors.New("No more ports available")
|
||||
}
|
||||
return -1, nil
|
||||
}
|
||||
|
||||
func (alloc *PortAllocator) Release(port int) error {
|
||||
select {
|
||||
case alloc.ports <- port:
|
||||
return nil
|
||||
default:
|
||||
return errors.New("Too many ports have been released")
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
func newPortAllocator(start, end int) (*PortAllocator, error) {
|
||||
allocator := &PortAllocator{}
|
||||
allocator.populate(start, end)
|
||||
return allocator, nil
|
||||
}
|
||||
|
||||
// IP allocator: Atomatically allocate and release networking ports
|
||||
type IPAllocator struct {
|
||||
network *net.IPNet
|
||||
queue chan (net.IP)
|
||||
}
|
||||
|
||||
func (alloc *IPAllocator) populate() error {
|
||||
firstIP, _ := networkRange(alloc.network)
|
||||
size, err := networkSize(alloc.network.Mask)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
|
@ -152,27 +226,131 @@ func (alloc *NetworkAllocator) populateFromNetwork(network *net.IPNet) error {
|
|||
return err
|
||||
}
|
||||
// Discard the network IP (that's the host IP address)
|
||||
if ip.Equal(network.IP) {
|
||||
if ip.Equal(alloc.network.IP) {
|
||||
continue
|
||||
}
|
||||
alloc.releaseIP(ip)
|
||||
alloc.queue <- ip
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
func (alloc *NetworkAllocator) Allocate() (*NetworkInterface, error) {
|
||||
// ipPrefixLen, _ := alloc.net.Mask.Size()
|
||||
ip, err := alloc.acquireIP()
|
||||
func (alloc *IPAllocator) Acquire() (net.IP, error) {
|
||||
select {
|
||||
case ip := <-alloc.queue:
|
||||
return ip, nil
|
||||
default:
|
||||
return net.IP{}, errors.New("No more IP addresses available")
|
||||
}
|
||||
return net.IP{}, nil
|
||||
}
|
||||
|
||||
func (alloc *IPAllocator) Release(ip net.IP) error {
|
||||
select {
|
||||
case alloc.queue <- ip:
|
||||
return nil
|
||||
default:
|
||||
return errors.New("Too many IP addresses have been released")
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
func newIPAllocator(network *net.IPNet) (*IPAllocator, error) {
|
||||
alloc := &IPAllocator{
|
||||
network: network,
|
||||
}
|
||||
if err := alloc.populate(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return alloc, nil
|
||||
}
|
||||
|
||||
// Network interface represents the networking stack of a container
|
||||
type NetworkInterface struct {
|
||||
IPNet net.IPNet
|
||||
Gateway net.IP
|
||||
|
||||
manager *NetworkManager
|
||||
extPorts []int
|
||||
}
|
||||
|
||||
// Allocate an external TCP port and map it to the interface
|
||||
func (iface *NetworkInterface) AllocatePort(port int) (int, error) {
|
||||
extPort, err := iface.manager.portAllocator.Acquire()
|
||||
if err != nil {
|
||||
return -1, err
|
||||
}
|
||||
if err := iface.manager.portMapper.Map(extPort, net.TCPAddr{iface.IPNet.IP, port}); err != nil {
|
||||
iface.manager.portAllocator.Release(extPort)
|
||||
return -1, err
|
||||
}
|
||||
iface.extPorts = append(iface.extPorts, extPort)
|
||||
return extPort, nil
|
||||
}
|
||||
|
||||
// Release: Network cleanup - release all resources
|
||||
func (iface *NetworkInterface) Release() error {
|
||||
for _, port := range iface.extPorts {
|
||||
if err := iface.manager.portMapper.Unmap(port); err != nil {
|
||||
log.Printf("Unable to unmap port %v: %v", port, err)
|
||||
}
|
||||
if err := iface.manager.portAllocator.Release(port); err != nil {
|
||||
log.Printf("Unable to release port %v: %v", port, err)
|
||||
}
|
||||
|
||||
}
|
||||
return iface.manager.ipAllocator.Release(iface.IPNet.IP)
|
||||
}
|
||||
|
||||
// Network Manager manages a set of network interfaces
|
||||
// Only *one* manager per host machine should be used
|
||||
type NetworkManager struct {
|
||||
bridgeIface string
|
||||
bridgeNetwork *net.IPNet
|
||||
|
||||
ipAllocator *IPAllocator
|
||||
portAllocator *PortAllocator
|
||||
portMapper *PortMapper
|
||||
}
|
||||
|
||||
// Allocate a network interface
|
||||
func (manager *NetworkManager) Allocate() (*NetworkInterface, error) {
|
||||
ip, err := manager.ipAllocator.Acquire()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
iface := &NetworkInterface{
|
||||
IPNet: net.IPNet{ip, alloc.net.Mask},
|
||||
Gateway: alloc.net.IP,
|
||||
IPNet: net.IPNet{ip, manager.bridgeNetwork.Mask},
|
||||
Gateway: manager.bridgeNetwork.IP,
|
||||
manager: manager,
|
||||
}
|
||||
return iface, nil
|
||||
}
|
||||
|
||||
func (alloc *NetworkAllocator) Release(iface *NetworkInterface) error {
|
||||
return alloc.releaseIP(iface.IPNet.IP)
|
||||
func newNetworkManager(bridgeIface string) (*NetworkManager, error) {
|
||||
addr, err := getIfaceAddr(bridgeIface)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
network := addr.(*net.IPNet)
|
||||
|
||||
ipAllocator, err := newIPAllocator(network)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
portAllocator, err := newPortAllocator(portRangeStart, portRangeEnd)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
portMapper, err := newPortMapper()
|
||||
|
||||
manager := &NetworkManager{
|
||||
bridgeIface: bridgeIface,
|
||||
bridgeNetwork: network,
|
||||
ipAllocator: ipAllocator,
|
||||
portAllocator: portAllocator,
|
||||
portMapper: portMapper,
|
||||
}
|
||||
return manager, nil
|
||||
}
|
||||
|
|
|
|||
|
|
@ -100,25 +100,27 @@ func TestConversion(t *testing.T) {
|
|||
}
|
||||
}
|
||||
|
||||
func TestNetworkAllocator(t *testing.T) {
|
||||
alloc := NetworkAllocator{}
|
||||
_, n, _ := net.ParseCIDR("127.0.0.1/29")
|
||||
alloc.populateFromNetwork(n)
|
||||
func TestIPAllocator(t *testing.T) {
|
||||
gwIP, n, _ := net.ParseCIDR("127.0.0.1/29")
|
||||
alloc, err := newIPAllocator(&net.IPNet{gwIP, n.Mask})
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
var lastIP net.IP
|
||||
for i := 0; i < 5; i++ {
|
||||
ip, err := alloc.acquireIP()
|
||||
ip, err := alloc.Acquire()
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
lastIP = ip
|
||||
}
|
||||
ip, err := alloc.acquireIP()
|
||||
ip, err := alloc.Acquire()
|
||||
if err == nil {
|
||||
t.Fatal("There shouldn't be any IP addresses at this point")
|
||||
}
|
||||
// Release 1 IP
|
||||
alloc.releaseIP(lastIP)
|
||||
ip, err = alloc.acquireIP()
|
||||
alloc.Release(lastIP)
|
||||
ip, err = alloc.Acquire()
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче