Added optional command line argument for interface selection

.gitignore

@@ -0,0 +1,2 @@
+iris
+Makefile

main.go

@@ -27,6 +27,7 @@ import (
 	"io/ioutil"
 	"log"
 	rng "math/rand"
+	"net"
 	"os"
 	"os/signal"
 	"runtime"
@@ -38,14 +39,19 @@ import (
 )
 
 // Command line flags
-var devMode = flag.Bool("dev", false, "start in local developer mode (random cluster and key)")
-var relayPort = flag.Int("port", 55555, "relay endpoint for locally connecting clients")
-var clusterName = flag.String("net", "", "name of the cluster to join or create")
-var rsaKeyPath = flag.String("rsa", "", "path to the RSA private key to use for data security")
-
-var cpuProfile = flag.String("cpuprof", "", "path to CPU profiling results")
-var heapProfile = flag.String("heapprof", "", "path to memory heap profiling results")
-var blockProfile = flag.String("blockprof", "", "path to lock contention profiling results")
+var (
+	devMode       = flag.Bool("dev", false, "start in local developer mode (random cluster and key)")
+	relayPort     = flag.Int("port", 55555, "relay endpoint for locally connecting clients")
+	clusterName   = flag.String("net", "", "name of the cluster to join or create")
+	rsaKeyPath    = flag.String("rsa", "", "path to the RSA private key to use for data security")
+	interfaceAddr = flag.String("if_addr", "", "ip/mask of the interface which is used to search for other nodes. if nothing is specified, all interfaces will be used.")
+	pastryPort    = flag.Int("pastry_port", 0, "port for incoming pastry connections. a value of 0 triggers makes iris choose a random port.")
+	tunnelPort    = flag.Int("tunnel_port", 0, "port for incoming tunnel connections. a value of 0 triggers makes iris choose a random port.")
+
+	cpuProfile   = flag.String("cpuprof", "", "path to CPU profiling results")
+	heapProfile  = flag.String("heapprof", "", "path to memory heap profiling results")
+	blockProfile = flag.String("blockprof", "", "path to lock contention profiling results")
+)
 
 // Prints the usage of the Iris command and its options.
 func usage() {
@@ -75,8 +81,11 @@ func usage() {
 }
 
 // Parses the command line flags and checks their validity
-func parseFlags() (int, string, *rsa.PrivateKey) {
-	var rsaKey *rsa.PrivateKey
+func parseFlags() (int, string, *rsa.PrivateKey, *net.IPNet, int, int) {
+	var (
+		rsaKey *rsa.PrivateKey
+		ifAddr *net.IPNet
+	)
 
 	// Read the command line arguments
 	flag.Usage = usage
@@ -136,13 +145,25 @@ func parseFlags() (int, string, *rsa.PrivateKey) {
 				}
 			}
 		}
+		if *interfaceAddr != "" {
+			var (
+				ip  net.IP
+				err error
+			)
+			ip, ifAddr, err = net.ParseCIDR(*interfaceAddr)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Failed to parse the interface address.\n")
+				os.Exit(-1)
+			}
+			ifAddr.IP = ip
+		}
 	}
-	return *relayPort, *clusterName, rsaKey
+	return *relayPort, *clusterName, rsaKey, ifAddr, *pastryPort, *tunnelPort
 }
 
 func main() {
 	// Extract the command line arguments
-	relayPort, clusterId, rsaKey := parseFlags()
+	relayPort, clusterId, rsaKey, ifAddr, pastryPort, tunnelPort := parseFlags()
 
 	// Check for CPU profiling
 	if *cpuProfile != "" {
@@ -176,7 +197,7 @@ func main() {
 	// Create and boot a new carrier
 	log.Printf("main: booting iris overlay...")
 	overlay := iris.New(clusterId, rsaKey)
-	if peers, err := overlay.Boot(); err != nil {
+	if peers, err := overlay.Boot(ifAddr, pastryPort, tunnelPort); err != nil {
 		log.Fatalf("main: failed to boot iris overlay: %v.", err)
 	} else {
 		log.Printf("main: iris overlay converged with %v remote connections.", peers)

proto/iris/overlay.go

@@ -58,17 +58,21 @@ func New(overId string, key *rsa.PrivateKey) *Overlay {
 	return o
 }
 
-// Boots the overlay, returning the number of remote peers.
-func (o *Overlay) Boot() (int, error) {
+// Boot starts up the overlay, returning the number of remote peers.
+func (o *Overlay) Boot(ifAddr *net.IPNet, pastryPort, tunnelPort int) (int, error) {
 	// Boot the underlay and wait until it converges
-	peers, err := o.scribe.Boot()
+	peers, err := o.scribe.Boot(ifAddr, pastryPort)
 	if err != nil {
 		return 0, err
 	}
-	// Start a tunnel acceptor on each network interface
-	addrs, err := net.InterfaceAddrs()
-	if err != nil {
-		return 0, err
+	var addrs []net.Addr
+	if ifAddr == nil {
+		// Start a tunnel acceptor on each network interface
+		if addrs, err = net.InterfaceAddrs(); err != nil {
+			return 0, err
+		}
+	} else {
+		addrs = append(addrs, ifAddr)
 	}
 	for _, addr := range addrs {
 		// Workaround for upstream Go issue #5395, extract IP from both IPNet and IPAddr
@@ -90,7 +94,7 @@ func (o *Overlay) Boot() (int, error) {
 
 			// Start and sync the acceptor
 			live := make(chan struct{})
-			go o.tunneler(ip, live, quit)
+			go o.tunneler(ip, tunnelPort, live, quit)
 			<-live
 		}
 	}

proto/iris/tunnel.go

@@ -60,9 +60,9 @@ func init() {
 	gob.Register(&dataHeader{})
 }
 
-func (o *Overlay) tunneler(ip net.IP, live chan struct{}, quit chan chan error) {
+func (o *Overlay) tunneler(ip net.IP, port int, live chan struct{}, quit chan chan error) {
 	// Listen for incoming streams on the given interface and random port.
-	addr, err := net.ResolveTCPAddr("tcp", net.JoinHostPort(ip.String(), "0"))
+	addr, err := net.ResolveTCPAddr("tcp", net.JoinHostPort(ip.String(), fmt.Sprintf("%d", port)))
 	if err != nil {
 		panic(fmt.Sprintf("failed to resolve interface (%v): %v.", ip, err))
 	}

proto/pastry/handshake.go

@@ -49,9 +49,9 @@ func init() {
 
 // Starts up the overlay networking on a specified interface and fans in all the
 // inbound connections into the overlay-global channels.
-func (o *Overlay) acceptor(ipnet *net.IPNet, quit chan chan error) {
+func (o *Overlay) acceptor(ipnet *net.IPNet, port int, quit chan chan error) {
 	// Listen for incoming session on the given interface and random port.
-	addr, err := net.ResolveTCPAddr("tcp", net.JoinHostPort(ipnet.IP.String(), "0"))
+	addr, err := net.ResolveTCPAddr("tcp", net.JoinHostPort(ipnet.IP.String(), fmt.Sprintf("%d", port)))
 	if err != nil {
 		panic(fmt.Sprintf("failed to resolve interface (%v): %v.", ipnet.IP, err))
 	}

proto/pastry/overlay.go

@@ -125,12 +125,17 @@ func New(id string, key *rsa.PrivateKey, app Callback) *Overlay {
 // Boots the overlay network: it starts up boostrappers and connection acceptors
 // on all local IPv4 interfaces, after which the overlay management is booted.
 // The method returns the number of remote peers after convergence is reached.
-func (o *Overlay) Boot() (int, error) {
-	// Start the individual acceptors
-	addrs, err := net.InterfaceAddrs()
-	if err != nil {
-		return 0, err
+func (o *Overlay) Boot(ifAddr *net.IPNet, port int) (int, error) {
+	var addrs []net.Addr
+	if ifAddr == nil {
+		var err error
+		if addrs, err = net.InterfaceAddrs(); err != nil {
+			return 0, err
+		}
+	} else {
+		addrs = append(addrs, ifAddr)
 	}
+
 	for _, addr := range addrs {
 		// Workaround for upstream Go issue #5395, construct an IPNet if IPAddr is returned
 		var ipnet *net.IPNet
@@ -152,7 +157,7 @@ func (o *Overlay) Boot() (int, error) {
 			// Create a quit channel and start the acceptor
 			quit := make(chan chan error)
 			o.acceptQuit = append(o.acceptQuit, quit)
-			go o.acceptor(ipnet, quit)
+			go o.acceptor(ipnet, port, quit)
 		}
 	}
 	// Start the overlay processes

proto/scribe/overlay.go

@@ -24,6 +24,7 @@ import (
 	"errors"
 	"log"
 	"math/big"
+	"net"
 	"sync"
 
 	"github.com/project-iris/iris/config"
@@ -71,14 +72,14 @@ func New(overId string, key *rsa.PrivateKey, app Callback) *Overlay {
 }
 
 // Boots the overlay, returning the number of remote peers.
-func (o *Overlay) Boot() (int, error) {
+func (o *Overlay) Boot(ifAddr *net.IPNet, pastryPort int) (int, error) {
 	log.Printf("scribe: booting with id %v.", o.pastry.Self())
 
 	// Start the heartbeat first since convergence can last long
 	o.heart.Start()
 
 	// Boot the overlay and wait until it converges
-	peers, err := o.pastry.Boot()
+	peers, err := o.pastry.Boot(ifAddr, pastryPort)
 	if err != nil {
 		return 0, err
 	}