Adding libnetwork support to publish on custom host port ranges.

See https://github.com/docker/docker/pull/12927 for docker portion.

Signed-off-by: Don Kjer <don.kjer@gmail.com>

libnetwork/drivers/bridge/port_mapping.go

@@ -57,6 +57,11 @@ func (n *bridgeNetwork) allocatePort(bnd *types.PortBinding, containerIP, defHos
 		bnd.HostIP = defHostIP
 	}
 
+	// Adjust HostPortEnd if this is not a range.
+	if bnd.HostPortEnd == 0 {
+		bnd.HostPortEnd = bnd.HostPort
+	}
+
 	// Construct the container side transport address
 	container, err := bnd.ContainerAddr()
 	if err != nil {
@@ -65,12 +70,12 @@ func (n *bridgeNetwork) allocatePort(bnd *types.PortBinding, containerIP, defHos
 
 	// Try up to maxAllocatePortAttempts times to get a port that's not already allocated.
 	for i := 0; i < maxAllocatePortAttempts; i++ {
-		if host, err = n.portMapper.Map(container, bnd.HostIP, int(bnd.HostPort), ulPxyEnabled); err == nil {
+		if host, err = n.portMapper.MapRange(container, bnd.HostIP, int(bnd.HostPort), int(bnd.HostPortEnd), ulPxyEnabled); err == nil {
 			break
 		}
 		// There is no point in immediately retrying to map an explicitly chosen port.
 		if bnd.HostPort != 0 {
-			logrus.Warnf("Failed to allocate and map port %d: %s", bnd.HostPort, err)
+			logrus.Warnf("Failed to allocate and map port %d-%d: %s", bnd.HostPort, bnd.HostPortEnd, err)
 			break
 		}
 		logrus.Warnf("Failed to allocate and map port: %s, retry: %d", err, i+1)

libnetwork/libnetwork_test.go

@@ -89,9 +89,11 @@ func getEmptyGenericOption() map[string]interface{} {
 
 func getPortMapping() []types.PortBinding {
 	return []types.PortBinding{
-		types.PortBinding{Proto: types.TCP, Port: uint16(230), HostPort: uint16(23000)},
-		types.PortBinding{Proto: types.UDP, Port: uint16(200), HostPort: uint16(22000)},
-		types.PortBinding{Proto: types.TCP, Port: uint16(120), HostPort: uint16(12000)},
+		{Proto: types.TCP, Port: uint16(230), HostPort: uint16(23000)},
+		{Proto: types.UDP, Port: uint16(200), HostPort: uint16(22000)},
+		{Proto: types.TCP, Port: uint16(120), HostPort: uint16(12000)},
+		{Proto: types.TCP, Port: uint16(320), HostPort: uint16(32000), HostPortEnd: uint16(32999)},
+		{Proto: types.UDP, Port: uint16(420), HostPort: uint16(42000), HostPortEnd: uint16(42001)},
 	}
 }
 
@@ -279,7 +281,7 @@ func TestBridge(t *testing.T) {
 	if !ok {
 		t.Fatalf("Unexpected format for port mapping in endpoint operational data")
 	}
-	if len(pm) != 3 {
+	if len(pm) != 5 {
 		t.Fatalf("Incomplete data for port mapping in endpoint operational data: %d", len(pm))
 	}
 

libnetwork/portallocator/portallocator.go

@@ -70,10 +70,15 @@ type (
 		Begin int
 		End   int
 	}
+	portRange struct {
+		begin int
+		end   int
+		last  int
+	}
 	portMap struct {
-		p          map[int]struct{}
-		begin, end int
-		last       int
+		p            map[int]struct{}
+		defaultRange string
+		portRanges   map[string]*portRange
 	}
 	protoMap map[string]*portMap
 )
@@ -123,8 +128,17 @@ func getDynamicPortRange() (start int, end int, err error) {
 
 // RequestPort requests new port from global ports pool for specified ip and proto.
 // If port is 0 it returns first free port. Otherwise it checks port availability
-// in pool and return that port or error if port is already busy.
+// in proto's pool and returns that port or error if port is already busy.
 func (p *PortAllocator) RequestPort(ip net.IP, proto string, port int) (int, error) {
+	return p.RequestPortInRange(ip, proto, port, port)
+}
+
+// RequestPortInRange requests new port from global ports pool for specified ip and proto.
+// If portStart and portEnd are 0 it returns the first free port in the default ephemeral range.
+// If portStart != portEnd it returns the first free port in the requested range.
+// Otherwise (portStart == portEnd) it checks port availability in the requested proto's port-pool
+// and returns that port or error if port is already busy.
+func (p *PortAllocator) RequestPortInRange(ip net.IP, proto string, portStart, portEnd int) (int, error) {
 	p.mutex.Lock()
 	defer p.mutex.Unlock()
 
@@ -146,15 +160,15 @@ func (p *PortAllocator) RequestPort(ip net.IP, proto string, port int) (int, err
 		p.ipMap[ipstr] = protomap
 	}
 	mapping := protomap[proto]
-	if port > 0 {
-		if _, ok := mapping.p[port]; !ok {
-			mapping.p[port] = struct{}{}
-			return port, nil
+	if portStart > 0 && portStart == portEnd {
+		if _, ok := mapping.p[portStart]; !ok {
+			mapping.p[portStart] = struct{}{}
+			return portStart, nil
 		}
-		return 0, newErrPortAlreadyAllocated(ipstr, port)
+		return 0, newErrPortAlreadyAllocated(ipstr, portStart)
 	}
 
-	port, err := mapping.findPort()
+	port, err := mapping.findPort(portStart, portEnd)
 	if err != nil {
 		return 0, err
 	}
@@ -178,12 +192,15 @@ func (p *PortAllocator) ReleasePort(ip net.IP, proto string, port int) error {
 }
 
 func (p *PortAllocator) newPortMap() *portMap {
-	return &portMap{
-		p:     map[int]struct{}{},
-		begin: p.Begin,
-		end:   p.End,
-		last:  p.End,
+	defaultKey := getRangeKey(p.Begin, p.End)
+	pm := &portMap{
+		p:            map[int]struct{}{},
+		defaultRange: defaultKey,
+		portRanges: map[string]*portRange{
+			defaultKey: newPortRange(p.Begin, p.End),
+		},
 	}
+	return pm
 }
 
 // ReleaseAll releases all ports for all ips.
@@ -194,17 +211,58 @@ func (p *PortAllocator) ReleaseAll() error {
 	return nil
 }
 
-func (pm *portMap) findPort() (int, error) {
-	port := pm.last
-	for i := 0; i <= pm.end-pm.begin; i++ {
+func getRangeKey(portStart, portEnd int) string {
+	return fmt.Sprintf("%d-%d", portStart, portEnd)
+}
+
+func newPortRange(portStart, portEnd int) *portRange {
+	return &portRange{
+		begin: portStart,
+		end:   portEnd,
+		last:  portEnd,
+	}
+}
+
+func (pm *portMap) getPortRange(portStart, portEnd int) (*portRange, error) {
+	var key string
+	if portStart == 0 && portEnd == 0 {
+		key = pm.defaultRange
+	} else {
+		key = getRangeKey(portStart, portEnd)
+		if portStart == portEnd ||
+			portStart == 0 || portEnd == 0 ||
+			portEnd < portStart {
+			return nil, fmt.Errorf("invalid port range: %s", key)
+		}
+	}
+
+	// Return existing port range, if already known.
+	if pr, exists := pm.portRanges[key]; exists {
+		return pr, nil
+	}
+
+	// Otherwise create a new port range.
+	pr := newPortRange(portStart, portEnd)
+	pm.portRanges[key] = pr
+	return pr, nil
+}
+
+func (pm *portMap) findPort(portStart, portEnd int) (int, error) {
+	pr, err := pm.getPortRange(portStart, portEnd)
+	if err != nil {
+		return 0, err
+	}
+	port := pr.last
+
+	for i := 0; i <= pr.end-pr.begin; i++ {
 		port++
-		if port > pm.end {
-			port = pm.begin
+		if port > pr.end {
+			port = pr.begin
 		}
 
 		if _, ok := pm.p[port]; !ok {
 			pm.p[port] = struct{}{}
-			pm.last = port
+			pr.last = port
 			return port, nil
 		}
 	}

libnetwork/portallocator/portallocator_test.go

@@ -236,6 +236,72 @@ func TestPortAllocation(t *testing.T) {
 	}
 }
 
+func TestPortAllocationWithCustomRange(t *testing.T) {
+	p := Get()
+	defer resetPortAllocator()
+
+	start, end := 8081, 8082
+	specificPort := 8000
+
+	//get an ephemeral port.
+	port1, err := p.RequestPortInRange(defaultIP, "tcp", 0, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//request invalid ranges
+	if _, err := p.RequestPortInRange(defaultIP, "tcp", 0, end); err == nil {
+		t.Fatalf("Expected error for invalid range %d-%d", 0, end)
+	}
+	if _, err := p.RequestPortInRange(defaultIP, "tcp", start, 0); err == nil {
+		t.Fatalf("Expected error for invalid range %d-%d", 0, end)
+	}
+	if _, err := p.RequestPortInRange(defaultIP, "tcp", 8081, 8080); err == nil {
+		t.Fatalf("Expected error for invalid range %d-%d", 0, end)
+	}
+
+	//request a single port
+	port, err := p.RequestPortInRange(defaultIP, "tcp", specificPort, specificPort)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if port != specificPort {
+		t.Fatalf("Expected port %d, got %d", specificPort, port)
+	}
+
+	//get a port from the range
+	port2, err := p.RequestPortInRange(defaultIP, "tcp", start, end)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if port2 < start || port2 > end {
+		t.Fatalf("Expected a port between %d and %d, got %d", start, end, port2)
+	}
+	//get another ephemeral port (should be > port1)
+	port3, err := p.RequestPortInRange(defaultIP, "tcp", 0, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if port3 < port1 {
+		t.Fatalf("Expected new port > %d in the ephemeral range, got %d", port1, port3)
+	}
+	//get another (and in this case the only other) port from the range
+	port4, err := p.RequestPortInRange(defaultIP, "tcp", start, end)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if port4 < start || port4 > end {
+		t.Fatalf("Expected a port between %d and %d, got %d", start, end, port4)
+	}
+	if port4 == port2 {
+		t.Fatal("Allocated the same port from a custom range")
+	}
+	//request 3rd port from the range of 2
+	if _, err := p.RequestPortInRange(defaultIP, "tcp", start, end); err != ErrAllPortsAllocated {
+		t.Fatalf("Expected error %s got %s", ErrAllPortsAllocated, err)
+	}
+}
+
 func TestNoDuplicateBPR(t *testing.T) {
 	p := Get()
 	defer resetPortAllocator()

libnetwork/portmapper/mapper.go

@@ -62,6 +62,11 @@ func (pm *PortMapper) SetIptablesChain(c *iptables.ChainInfo, bridgeName string)
 
 // Map maps the specified container transport address to the host's network address and transport port
 func (pm *PortMapper) Map(container net.Addr, hostIP net.IP, hostPort int, useProxy bool) (host net.Addr, err error) {
+	return pm.MapRange(container, hostIP, hostPort, hostPort, useProxy)
+}
+
+// MapRange maps the specified container transport address to the host's network address and transport port range
+func (pm *PortMapper) MapRange(container net.Addr, hostIP net.IP, hostPortStart, hostPortEnd int, useProxy bool) (host net.Addr, err error) {
 	pm.lock.Lock()
 	defer pm.lock.Unlock()
 
@@ -74,7 +79,7 @@ func (pm *PortMapper) Map(container net.Addr, hostIP net.IP, hostPort int, usePr
 	switch container.(type) {
 	case *net.TCPAddr:
 		proto = "tcp"
-		if allocatedHostPort, err = pm.Allocator.RequestPort(hostIP, proto, hostPort); err != nil {
+		if allocatedHostPort, err = pm.Allocator.RequestPortInRange(hostIP, proto, hostPortStart, hostPortEnd); err != nil {
 			return nil, err
 		}
 
@@ -91,7 +96,7 @@ func (pm *PortMapper) Map(container net.Addr, hostIP net.IP, hostPort int, usePr
 		}
 	case *net.UDPAddr:
 		proto = "udp"
-		if allocatedHostPort, err = pm.Allocator.RequestPort(hostIP, proto, hostPort); err != nil {
+		if allocatedHostPort, err = pm.Allocator.RequestPortInRange(hostIP, proto, hostPortStart, hostPortEnd); err != nil {
 			return nil, err
 		}
 

libnetwork/types/types.go

@@ -24,11 +24,12 @@ func (t *TransportPort) GetCopy() TransportPort {
 
 // PortBinding represent a port binding between the container and the host
 type PortBinding struct {
-	Proto    Protocol
-	IP       net.IP
-	Port     uint16
-	HostIP   net.IP
-	HostPort uint16
+	Proto       Protocol
+	IP          net.IP
+	Port        uint16
+	HostIP      net.IP
+	HostPort    uint16
+	HostPortEnd uint16
 }
 
 // HostAddr returns the host side transport address
@@ -58,11 +59,12 @@ func (p PortBinding) ContainerAddr() (net.Addr, error) {
 // GetCopy returns a copy of this PortBinding structure instance
 func (p *PortBinding) GetCopy() PortBinding {
 	return PortBinding{
-		Proto:    p.Proto,
-		IP:       GetIPCopy(p.IP),
-		Port:     p.Port,
-		HostIP:   GetIPCopy(p.HostIP),
-		HostPort: p.HostPort,
+		Proto:       p.Proto,
+		IP:          GetIPCopy(p.IP),
+		Port:        p.Port,
+		HostIP:      GetIPCopy(p.HostIP),
+		HostPort:    p.HostPort,
+		HostPortEnd: p.HostPortEnd,
 	}
 }
 
@@ -76,7 +78,8 @@ func (p *PortBinding) Equal(o *PortBinding) bool {
 		return false
 	}
 
-	if p.Proto != o.Proto || p.Port != o.Port || p.HostPort != o.HostPort {
+	if p.Proto != o.Proto || p.Port != o.Port ||
+		p.HostPort != o.HostPort || p.HostPortEnd != o.HostPortEnd {
 		return false
 	}