diff --git a/libnetwork/Makefile b/libnetwork/Makefile index 899ca4b9be..a130dc656d 100644 --- a/libnetwork/Makefile +++ b/libnetwork/Makefile @@ -7,6 +7,7 @@ docker = docker run --rm -it ${dockerargs} $$EXTRA_ARGS ${container_env} ${build ciargs = -e CIRCLECI -e "COVERALLS_TOKEN=$$COVERALLS_TOKEN" -e "INSIDECONTAINER=-incontainer=true" cidocker = docker run ${dockerargs} ${ciargs} $$EXTRA_ARGS ${container_env} ${build_image} CROSS_PLATFORMS = linux/amd64 linux/386 linux/arm windows/amd64 +export PATH := $(CURDIR)/bin:$(PATH) all: ${build_image}.created build check integration-tests clean @@ -24,10 +25,11 @@ build: ${build_image}.created build-local: @mkdir -p "bin" $(shell which godep) go build -tags experimental -o "bin/dnet" ./cmd/dnet + $(shell which godep) go build -o "bin/docker-proxy" ./cmd/proxy clean: @if [ -d bin ]; then \ - echo "Removing dnet binaries"; \ + echo "Removing dnet and proxy binaries"; \ rm -rf bin; \ fi @@ -41,6 +43,7 @@ cross: ${build_image}.created cross-local: $(shell which godep) go build -o "bin/dnet-$$GOOS-$$GOARCH" ./cmd/dnet + $(shell which godep) go build -o "bin/docker-proxy-$$GOOS-$$GOARCH" ./cmd/proxy check: ${build_image}.created @${docker} ./wrapmake.sh check-local @@ -102,4 +105,4 @@ circle-ci-check: ${build_image}.created circle-ci-build: ${build_image}.created @${cidocker} make build-local -circle-ci: circle-ci-check circle-ci-cross circle-ci-build integration-tests +circle-ci: circle-ci-build circle-ci-check circle-ci-cross integration-tests diff --git a/libnetwork/cmd/proxy/main.go b/libnetwork/cmd/proxy/main.go new file mode 100644 index 0000000000..fb68796148 --- /dev/null +++ b/libnetwork/cmd/proxy/main.go @@ -0,0 +1,67 @@ +package main + +import ( + "flag" + "fmt" + "log" + "net" + "os" + "os/signal" + "syscall" +) + +func main() { + f := os.NewFile(3, "signal-parent") + host, container := parseHostContainerAddrs() + + p, err := NewProxy(host, container) + if err != nil { + fmt.Fprintf(f, "1\n%s", err) + f.Close() + os.Exit(1) + } + go handleStopSignals(p) + fmt.Fprint(f, "0\n") + f.Close() + + // Run will block until the proxy stops + p.Run() +} + +// parseHostContainerAddrs parses the flags passed on reexec to create the TCP or UDP +// net.Addrs to map the host and container ports +func parseHostContainerAddrs() (host net.Addr, container net.Addr) { + var ( + proto = flag.String("proto", "tcp", "proxy protocol") + hostIP = flag.String("host-ip", "", "host ip") + hostPort = flag.Int("host-port", -1, "host port") + containerIP = flag.String("container-ip", "", "container ip") + containerPort = flag.Int("container-port", -1, "container port") + ) + + flag.Parse() + + switch *proto { + case "tcp": + host = &net.TCPAddr{IP: net.ParseIP(*hostIP), Port: *hostPort} + container = &net.TCPAddr{IP: net.ParseIP(*containerIP), Port: *containerPort} + case "udp": + host = &net.UDPAddr{IP: net.ParseIP(*hostIP), Port: *hostPort} + container = &net.UDPAddr{IP: net.ParseIP(*containerIP), Port: *containerPort} + default: + log.Fatalf("unsupported protocol %s", *proto) + } + + return host, container +} + +func handleStopSignals(p Proxy) { + s := make(chan os.Signal, 10) + signal.Notify(s, os.Interrupt, syscall.SIGTERM) + + for range s { + p.Close() + + os.Exit(0) + } +} diff --git a/libnetwork/cmd/proxy/network_proxy_test.go b/libnetwork/cmd/proxy/network_proxy_test.go new file mode 100644 index 0000000000..b3379dabb3 --- /dev/null +++ b/libnetwork/cmd/proxy/network_proxy_test.go @@ -0,0 +1,219 @@ +package main + +import ( + "bytes" + "flag" + "fmt" + "io" + "net" + "strings" + "testing" + "time" +) + +var _ = flag.Bool("incontainer", false, "Indicates if the test is running in a container") + +var testBuf = []byte("Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo") +var testBufSize = len(testBuf) + +type EchoServer interface { + Run() + Close() + LocalAddr() net.Addr +} + +type TCPEchoServer struct { + listener net.Listener + testCtx *testing.T +} + +type UDPEchoServer struct { + conn net.PacketConn + testCtx *testing.T +} + +func NewEchoServer(t *testing.T, proto, address string) EchoServer { + var server EchoServer + if strings.HasPrefix(proto, "tcp") { + listener, err := net.Listen(proto, address) + if err != nil { + t.Fatal(err) + } + server = &TCPEchoServer{listener: listener, testCtx: t} + } else { + socket, err := net.ListenPacket(proto, address) + if err != nil { + t.Fatal(err) + } + server = &UDPEchoServer{conn: socket, testCtx: t} + } + return server +} + +func (server *TCPEchoServer) Run() { + go func() { + for { + client, err := server.listener.Accept() + if err != nil { + return + } + go func(client net.Conn) { + if _, err := io.Copy(client, client); err != nil { + server.testCtx.Logf("can't echo to the client: %v\n", err.Error()) + } + client.Close() + }(client) + } + }() +} + +func (server *TCPEchoServer) LocalAddr() net.Addr { return server.listener.Addr() } +func (server *TCPEchoServer) Close() { server.listener.Close() } + +func (server *UDPEchoServer) Run() { + go func() { + readBuf := make([]byte, 1024) + for { + read, from, err := server.conn.ReadFrom(readBuf) + if err != nil { + return + } + for i := 0; i != read; { + written, err := server.conn.WriteTo(readBuf[i:read], from) + if err != nil { + break + } + i += written + } + } + }() +} + +func (server *UDPEchoServer) LocalAddr() net.Addr { return server.conn.LocalAddr() } +func (server *UDPEchoServer) Close() { server.conn.Close() } + +func testProxyAt(t *testing.T, proto string, proxy Proxy, addr string) { + defer proxy.Close() + go proxy.Run() + client, err := net.Dial(proto, addr) + if err != nil { + t.Fatalf("Can't connect to the proxy: %v", err) + } + defer client.Close() + client.SetDeadline(time.Now().Add(10 * time.Second)) + if _, err = client.Write(testBuf); err != nil { + t.Fatal(err) + } + recvBuf := make([]byte, testBufSize) + if _, err = client.Read(recvBuf); err != nil { + t.Fatal(err) + } + if !bytes.Equal(testBuf, recvBuf) { + t.Fatal(fmt.Errorf("Expected [%v] but got [%v]", testBuf, recvBuf)) + } +} + +func testProxy(t *testing.T, proto string, proxy Proxy) { + testProxyAt(t, proto, proxy, proxy.FrontendAddr().String()) +} + +func TestTCP4Proxy(t *testing.T) { + backend := NewEchoServer(t, "tcp", "127.0.0.1:0") + defer backend.Close() + backend.Run() + frontendAddr := &net.TCPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0} + proxy, err := NewProxy(frontendAddr, backend.LocalAddr()) + if err != nil { + t.Fatal(err) + } + testProxy(t, "tcp", proxy) +} + +func TestTCP6Proxy(t *testing.T) { + backend := NewEchoServer(t, "tcp", "[::1]:0") + defer backend.Close() + backend.Run() + frontendAddr := &net.TCPAddr{IP: net.IPv6loopback, Port: 0} + proxy, err := NewProxy(frontendAddr, backend.LocalAddr()) + if err != nil { + t.Fatal(err) + } + testProxy(t, "tcp", proxy) +} + +func TestTCPDualStackProxy(t *testing.T) { + // If I understand `godoc -src net favoriteAddrFamily` (used by the + // net.Listen* functions) correctly this should work, but it doesn't. + t.Skip("No support for dual stack yet") + backend := NewEchoServer(t, "tcp", "[::1]:0") + defer backend.Close() + backend.Run() + frontendAddr := &net.TCPAddr{IP: net.IPv6loopback, Port: 0} + proxy, err := NewProxy(frontendAddr, backend.LocalAddr()) + if err != nil { + t.Fatal(err) + } + ipv4ProxyAddr := &net.TCPAddr{ + IP: net.IPv4(127, 0, 0, 1), + Port: proxy.FrontendAddr().(*net.TCPAddr).Port, + } + testProxyAt(t, "tcp", proxy, ipv4ProxyAddr.String()) +} + +func TestUDP4Proxy(t *testing.T) { + backend := NewEchoServer(t, "udp", "127.0.0.1:0") + defer backend.Close() + backend.Run() + frontendAddr := &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0} + proxy, err := NewProxy(frontendAddr, backend.LocalAddr()) + if err != nil { + t.Fatal(err) + } + testProxy(t, "udp", proxy) +} + +func TestUDP6Proxy(t *testing.T) { + backend := NewEchoServer(t, "udp", "[::1]:0") + defer backend.Close() + backend.Run() + frontendAddr := &net.UDPAddr{IP: net.IPv6loopback, Port: 0} + proxy, err := NewProxy(frontendAddr, backend.LocalAddr()) + if err != nil { + t.Fatal(err) + } + testProxy(t, "udp", proxy) +} + +func TestUDPWriteError(t *testing.T) { + frontendAddr := &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0} + // Hopefully, this port will be free: */ + backendAddr := &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 25587} + proxy, err := NewProxy(frontendAddr, backendAddr) + if err != nil { + t.Fatal(err) + } + defer proxy.Close() + go proxy.Run() + client, err := net.Dial("udp", "127.0.0.1:25587") + if err != nil { + t.Fatalf("Can't connect to the proxy: %v", err) + } + defer client.Close() + // Make sure the proxy doesn't stop when there is no actual backend: + client.Write(testBuf) + client.Write(testBuf) + backend := NewEchoServer(t, "udp", "127.0.0.1:25587") + defer backend.Close() + backend.Run() + client.SetDeadline(time.Now().Add(10 * time.Second)) + if _, err = client.Write(testBuf); err != nil { + t.Fatal(err) + } + recvBuf := make([]byte, testBufSize) + if _, err = client.Read(recvBuf); err != nil { + t.Fatal(err) + } + if !bytes.Equal(testBuf, recvBuf) { + t.Fatal(fmt.Errorf("Expected [%v] but got [%v]", testBuf, recvBuf)) + } +} diff --git a/libnetwork/cmd/proxy/proxy.go b/libnetwork/cmd/proxy/proxy.go new file mode 100644 index 0000000000..44dd177bb6 --- /dev/null +++ b/libnetwork/cmd/proxy/proxy.go @@ -0,0 +1,37 @@ +// docker-proxy provides a network Proxy interface and implementations for TCP +// and UDP. +package main + +import ( + "fmt" + "net" +) + +// Proxy defines the behavior of a proxy. It forwards traffic back and forth +// between two endpoints : the frontend and the backend. +// It can be used to do software port-mapping between two addresses. +// e.g. forward all traffic between the frontend (host) 127.0.0.1:3000 +// to the backend (container) at 172.17.42.108:4000. +type Proxy interface { + // Run starts forwarding traffic back and forth between the front + // and back-end addresses. + Run() + // Close stops forwarding traffic and close both ends of the Proxy. + Close() + // FrontendAddr returns the address on which the proxy is listening. + FrontendAddr() net.Addr + // BackendAddr returns the proxied address. + BackendAddr() net.Addr +} + +// NewProxy creates a Proxy according to the specified frontendAddr and backendAddr. +func NewProxy(frontendAddr, backendAddr net.Addr) (Proxy, error) { + switch frontendAddr.(type) { + case *net.UDPAddr: + return NewUDPProxy(frontendAddr.(*net.UDPAddr), backendAddr.(*net.UDPAddr)) + case *net.TCPAddr: + return NewTCPProxy(frontendAddr.(*net.TCPAddr), backendAddr.(*net.TCPAddr)) + default: + panic(fmt.Errorf("Unsupported protocol")) + } +} diff --git a/libnetwork/cmd/proxy/stub_proxy.go b/libnetwork/cmd/proxy/stub_proxy.go new file mode 100644 index 0000000000..95e0e36352 --- /dev/null +++ b/libnetwork/cmd/proxy/stub_proxy.go @@ -0,0 +1,31 @@ +package main + +import ( + "net" +) + +// StubProxy is a proxy that is a stub (does nothing). +type StubProxy struct { + frontendAddr net.Addr + backendAddr net.Addr +} + +// Run does nothing. +func (p *StubProxy) Run() {} + +// Close does nothing. +func (p *StubProxy) Close() {} + +// FrontendAddr returns the frontend address. +func (p *StubProxy) FrontendAddr() net.Addr { return p.frontendAddr } + +// BackendAddr returns the backend address. +func (p *StubProxy) BackendAddr() net.Addr { return p.backendAddr } + +// NewStubProxy creates a new StubProxy +func NewStubProxy(frontendAddr, backendAddr net.Addr) (Proxy, error) { + return &StubProxy{ + frontendAddr: frontendAddr, + backendAddr: backendAddr, + }, nil +} diff --git a/libnetwork/cmd/proxy/tcp_proxy.go b/libnetwork/cmd/proxy/tcp_proxy.go new file mode 100644 index 0000000000..514b778773 --- /dev/null +++ b/libnetwork/cmd/proxy/tcp_proxy.go @@ -0,0 +1,96 @@ +package main + +import ( + "io" + "net" + "sync" + "syscall" + + "github.com/Sirupsen/logrus" +) + +// TCPProxy is a proxy for TCP connections. It implements the Proxy interface to +// handle TCP traffic forwarding between the frontend and backend addresses. +type TCPProxy struct { + listener *net.TCPListener + frontendAddr *net.TCPAddr + backendAddr *net.TCPAddr +} + +// NewTCPProxy creates a new TCPProxy. +func NewTCPProxy(frontendAddr, backendAddr *net.TCPAddr) (*TCPProxy, error) { + listener, err := net.ListenTCP("tcp", frontendAddr) + if err != nil { + return nil, err + } + // If the port in frontendAddr was 0 then ListenTCP will have a picked + // a port to listen on, hence the call to Addr to get that actual port: + return &TCPProxy{ + listener: listener, + frontendAddr: listener.Addr().(*net.TCPAddr), + backendAddr: backendAddr, + }, nil +} + +func (proxy *TCPProxy) clientLoop(client *net.TCPConn, quit chan bool) { + backend, err := net.DialTCP("tcp", nil, proxy.backendAddr) + if err != nil { + logrus.Printf("Can't forward traffic to backend tcp/%v: %s\n", proxy.backendAddr, err) + client.Close() + return + } + + var wg sync.WaitGroup + var broker = func(to, from *net.TCPConn) { + if _, err := io.Copy(to, from); err != nil { + // If the socket we are writing to is shutdown with + // SHUT_WR, forward it to the other end of the pipe: + if err, ok := err.(*net.OpError); ok && err.Err == syscall.EPIPE { + from.CloseWrite() + } + } + to.CloseRead() + wg.Done() + } + + wg.Add(2) + go broker(client, backend) + go broker(backend, client) + + finish := make(chan struct{}) + go func() { + wg.Wait() + close(finish) + }() + + select { + case <-quit: + case <-finish: + } + client.Close() + backend.Close() + <-finish +} + +// Run starts forwarding the traffic using TCP. +func (proxy *TCPProxy) Run() { + quit := make(chan bool) + defer close(quit) + for { + client, err := proxy.listener.Accept() + if err != nil { + logrus.Printf("Stopping proxy on tcp/%v for tcp/%v (%s)", proxy.frontendAddr, proxy.backendAddr, err) + return + } + go proxy.clientLoop(client.(*net.TCPConn), quit) + } +} + +// Close stops forwarding the traffic. +func (proxy *TCPProxy) Close() { proxy.listener.Close() } + +// FrontendAddr returns the TCP address on which the proxy is listening. +func (proxy *TCPProxy) FrontendAddr() net.Addr { return proxy.frontendAddr } + +// BackendAddr returns the TCP proxied address. +func (proxy *TCPProxy) BackendAddr() net.Addr { return proxy.backendAddr } diff --git a/libnetwork/cmd/proxy/udp_proxy.go b/libnetwork/cmd/proxy/udp_proxy.go new file mode 100644 index 0000000000..2b895ae9d4 --- /dev/null +++ b/libnetwork/cmd/proxy/udp_proxy.go @@ -0,0 +1,169 @@ +package main + +import ( + "encoding/binary" + "net" + "strings" + "sync" + "syscall" + "time" + + "github.com/Sirupsen/logrus" +) + +const ( + // UDPConnTrackTimeout is the timeout used for UDP connection tracking + UDPConnTrackTimeout = 90 * time.Second + // UDPBufSize is the buffer size for the UDP proxy + UDPBufSize = 65507 +) + +// A net.Addr where the IP is split into two fields so you can use it as a key +// in a map: +type connTrackKey struct { + IPHigh uint64 + IPLow uint64 + Port int +} + +func newConnTrackKey(addr *net.UDPAddr) *connTrackKey { + if len(addr.IP) == net.IPv4len { + return &connTrackKey{ + IPHigh: 0, + IPLow: uint64(binary.BigEndian.Uint32(addr.IP)), + Port: addr.Port, + } + } + return &connTrackKey{ + IPHigh: binary.BigEndian.Uint64(addr.IP[:8]), + IPLow: binary.BigEndian.Uint64(addr.IP[8:]), + Port: addr.Port, + } +} + +type connTrackMap map[connTrackKey]*net.UDPConn + +// UDPProxy is proxy for which handles UDP datagrams. It implements the Proxy +// interface to handle UDP traffic forwarding between the frontend and backend +// addresses. +type UDPProxy struct { + listener *net.UDPConn + frontendAddr *net.UDPAddr + backendAddr *net.UDPAddr + connTrackTable connTrackMap + connTrackLock sync.Mutex +} + +// NewUDPProxy creates a new UDPProxy. +func NewUDPProxy(frontendAddr, backendAddr *net.UDPAddr) (*UDPProxy, error) { + listener, err := net.ListenUDP("udp", frontendAddr) + if err != nil { + return nil, err + } + return &UDPProxy{ + listener: listener, + frontendAddr: listener.LocalAddr().(*net.UDPAddr), + backendAddr: backendAddr, + connTrackTable: make(connTrackMap), + }, nil +} + +func (proxy *UDPProxy) replyLoop(proxyConn *net.UDPConn, clientAddr *net.UDPAddr, clientKey *connTrackKey) { + defer func() { + proxy.connTrackLock.Lock() + delete(proxy.connTrackTable, *clientKey) + proxy.connTrackLock.Unlock() + proxyConn.Close() + }() + + readBuf := make([]byte, UDPBufSize) + for { + proxyConn.SetReadDeadline(time.Now().Add(UDPConnTrackTimeout)) + again: + read, err := proxyConn.Read(readBuf) + if err != nil { + if err, ok := err.(*net.OpError); ok && err.Err == syscall.ECONNREFUSED { + // This will happen if the last write failed + // (e.g: nothing is actually listening on the + // proxied port on the container), ignore it + // and continue until UDPConnTrackTimeout + // expires: + goto again + } + return + } + for i := 0; i != read; { + written, err := proxy.listener.WriteToUDP(readBuf[i:read], clientAddr) + if err != nil { + return + } + i += written + } + } +} + +// Run starts forwarding the traffic using UDP. +func (proxy *UDPProxy) Run() { + readBuf := make([]byte, UDPBufSize) + for { + read, from, err := proxy.listener.ReadFromUDP(readBuf) + if err != nil { + // NOTE: Apparently ReadFrom doesn't return + // ECONNREFUSED like Read do (see comment in + // UDPProxy.replyLoop) + if !isClosedError(err) { + logrus.Printf("Stopping proxy on udp/%v for udp/%v (%s)", proxy.frontendAddr, proxy.backendAddr, err) + } + break + } + + fromKey := newConnTrackKey(from) + proxy.connTrackLock.Lock() + proxyConn, hit := proxy.connTrackTable[*fromKey] + if !hit { + proxyConn, err = net.DialUDP("udp", nil, proxy.backendAddr) + if err != nil { + logrus.Printf("Can't proxy a datagram to udp/%s: %s\n", proxy.backendAddr, err) + proxy.connTrackLock.Unlock() + continue + } + proxy.connTrackTable[*fromKey] = proxyConn + go proxy.replyLoop(proxyConn, from, fromKey) + } + proxy.connTrackLock.Unlock() + for i := 0; i != read; { + written, err := proxyConn.Write(readBuf[i:read]) + if err != nil { + logrus.Printf("Can't proxy a datagram to udp/%s: %s\n", proxy.backendAddr, err) + break + } + i += written + } + } +} + +// Close stops forwarding the traffic. +func (proxy *UDPProxy) Close() { + proxy.listener.Close() + proxy.connTrackLock.Lock() + defer proxy.connTrackLock.Unlock() + for _, conn := range proxy.connTrackTable { + conn.Close() + } +} + +// FrontendAddr returns the UDP address on which the proxy is listening. +func (proxy *UDPProxy) FrontendAddr() net.Addr { return proxy.frontendAddr } + +// BackendAddr returns the proxied UDP address. +func (proxy *UDPProxy) BackendAddr() net.Addr { return proxy.backendAddr } + +func isClosedError(err error) bool { + /* This comparison is ugly, but unfortunately, net.go doesn't export errClosing. + * See: + * http://golang.org/src/pkg/net/net.go + * https://code.google.com/p/go/issues/detail?id=4337 + * https://groups.google.com/forum/#!msg/golang-nuts/0_aaCvBmOcM/SptmDyX1XJMJ + */ + return strings.HasSuffix(err.Error(), "use of closed network connection") +} diff --git a/libnetwork/portmapper/mapper.go b/libnetwork/portmapper/mapper.go index d125fa8d4b..0bf7630557 100644 --- a/libnetwork/portmapper/mapper.go +++ b/libnetwork/portmapper/mapper.go @@ -90,7 +90,10 @@ func (pm *PortMapper) MapRange(container net.Addr, hostIP net.IP, hostPortStart, } if useProxy { - m.userlandProxy = newProxy(proto, hostIP, allocatedHostPort, container.(*net.TCPAddr).IP, container.(*net.TCPAddr).Port) + m.userlandProxy, err = newProxy(proto, hostIP, allocatedHostPort, container.(*net.TCPAddr).IP, container.(*net.TCPAddr).Port) + if err != nil { + return nil, err + } } else { m.userlandProxy = newDummyProxy(proto, hostIP, allocatedHostPort) } @@ -107,7 +110,10 @@ func (pm *PortMapper) MapRange(container net.Addr, hostIP net.IP, hostPortStart, } if useProxy { - m.userlandProxy = newProxy(proto, hostIP, allocatedHostPort, container.(*net.UDPAddr).IP, container.(*net.UDPAddr).Port) + m.userlandProxy, err = newProxy(proto, hostIP, allocatedHostPort, container.(*net.UDPAddr).IP, container.(*net.UDPAddr).Port) + if err != nil { + return nil, err + } } else { m.userlandProxy = newDummyProxy(proto, hostIP, allocatedHostPort) } diff --git a/libnetwork/portmapper/mock_proxy.go b/libnetwork/portmapper/mock_proxy.go index 29b1605889..587026f9ce 100644 --- a/libnetwork/portmapper/mock_proxy.go +++ b/libnetwork/portmapper/mock_proxy.go @@ -2,8 +2,8 @@ package portmapper import "net" -func newMockProxyCommand(proto string, hostIP net.IP, hostPort int, containerIP net.IP, containerPort int) userlandProxy { - return &mockProxyCommand{} +func newMockProxyCommand(proto string, hostIP net.IP, hostPort int, containerIP net.IP, containerPort int) (userlandProxy, error) { + return &mockProxyCommand{}, nil } type mockProxyCommand struct { diff --git a/libnetwork/portmapper/proxy.go b/libnetwork/portmapper/proxy.go index ddde2744c2..25a341a98f 100644 --- a/libnetwork/portmapper/proxy.go +++ b/libnetwork/portmapper/proxy.go @@ -1,29 +1,19 @@ package portmapper import ( - "flag" "fmt" "io" "io/ioutil" - "log" "net" "os" "os/exec" - "os/signal" "strconv" "syscall" "time" - - "github.com/docker/docker/pkg/proxy" - "github.com/docker/docker/pkg/reexec" ) const userlandProxyCommandName = "docker-proxy" -func init() { - reexec.Register(userlandProxyCommandName, execProxy) -} - type userlandProxy interface { Start() error Stop() error @@ -35,66 +25,15 @@ type proxyCommand struct { cmd *exec.Cmd } -// execProxy is the reexec function that is registered to start the userland proxies -func execProxy() { - f := os.NewFile(3, "signal-parent") - host, container := parseHostContainerAddrs() +func newProxyCommand(proto string, hostIP net.IP, hostPort int, containerIP net.IP, containerPort int) (userlandProxy, error) { + cmd, err := exec.LookPath(userlandProxyCommandName) - p, err := proxy.NewProxy(host, container) if err != nil { - fmt.Fprintf(f, "1\n%s", err) - f.Close() - os.Exit(1) - } - go handleStopSignals(p) - fmt.Fprint(f, "0\n") - f.Close() - - // Run will block until the proxy stops - p.Run() -} - -// parseHostContainerAddrs parses the flags passed on reexec to create the TCP or UDP -// net.Addrs to map the host and container ports -func parseHostContainerAddrs() (host net.Addr, container net.Addr) { - var ( - proto = flag.String("proto", "tcp", "proxy protocol") - hostIP = flag.String("host-ip", "", "host ip") - hostPort = flag.Int("host-port", -1, "host port") - containerIP = flag.String("container-ip", "", "container ip") - containerPort = flag.Int("container-port", -1, "container port") - ) - - flag.Parse() - - switch *proto { - case "tcp": - host = &net.TCPAddr{IP: net.ParseIP(*hostIP), Port: *hostPort} - container = &net.TCPAddr{IP: net.ParseIP(*containerIP), Port: *containerPort} - case "udp": - host = &net.UDPAddr{IP: net.ParseIP(*hostIP), Port: *hostPort} - container = &net.UDPAddr{IP: net.ParseIP(*containerIP), Port: *containerPort} - default: - log.Fatalf("unsupported protocol %s", *proto) + return nil, err } - return host, container -} - -func handleStopSignals(p proxy.Proxy) { - s := make(chan os.Signal, 10) - signal.Notify(s, os.Interrupt, syscall.SIGTERM, syscall.SIGSTOP) - - for range s { - p.Close() - - os.Exit(0) - } -} - -func newProxyCommand(proto string, hostIP net.IP, hostPort int, containerIP net.IP, containerPort int) userlandProxy { args := []string{ - userlandProxyCommandName, + cmd, "-proto", proto, "-host-ip", hostIP.String(), "-host-port", strconv.Itoa(hostPort), @@ -104,13 +43,13 @@ func newProxyCommand(proto string, hostIP net.IP, hostPort int, containerIP net. return &proxyCommand{ cmd: &exec.Cmd{ - Path: reexec.Self(), + Path: cmd, Args: args, SysProcAttr: &syscall.SysProcAttr{ Pdeathsig: syscall.SIGTERM, // send a sigterm to the proxy if the daemon process dies }, }, - } + }, nil } func (p *proxyCommand) Start() error {