Merge pull request #797 from hashicorp/reserve-ports

Reserving ports for client in every platform

command/agent/agent.go

@@ -7,11 +7,11 @@ import (
 	"net"
 	"os"
 	"path/filepath"
-	"runtime"
 	"sync"
 	"time"
 
 	"github.com/hashicorp/nomad/client"
+	clientconfig "github.com/hashicorp/nomad/client/config"
 	"github.com/hashicorp/nomad/nomad"
 	"github.com/hashicorp/nomad/nomad/structs"
 )
@@ -242,26 +242,8 @@ func (a *Agent) setupClient() error {
 	conf.Node.HTTPAddr = httpAddr
 
 	// Reserve some ports for the plugins
-	if runtime.GOOS == "windows" {
-		deviceName, err := a.findLoopbackDevice()
-		if err != nil {
-			return fmt.Errorf("error finding the device name for loopback: %v", err)
-		}
-		var nr *structs.NetworkResource
-		for _, n := range conf.Node.Reserved.Networks {
-			if n.Device == deviceName {
-				nr = n
-			}
-		}
-		if nr == nil {
-			nr = &structs.NetworkResource{
-				Device:        deviceName,
-				ReservedPorts: make([]structs.Port, 0),
-			}
-		}
-		for i := conf.ClientMinPort; i <= conf.ClientMaxPort; i++ {
-			nr.ReservedPorts = append(nr.ReservedPorts, structs.Port{Label: fmt.Sprintf("plugin-%d", i), Value: int(i)})
-		}
+	if err := a.reservePortsForClient(conf); err != nil {
+		return err
 	}
 
 	// Create the client
@@ -273,26 +255,75 @@ func (a *Agent) setupClient() error {
 	return nil
 }
 
-func (a *Agent) findLoopbackDevice() (string, error) {
+// reservePortsForClient reservers a range of ports for the client to use when
+// it creates various plugins for log collection, executors, drivers, etc
+func (a *Agent) reservePortsForClient(conf *clientconfig.Config) error {
+	// finding the device name for loopback
+	deviceName, addr, mask, err := a.findLoopbackDevice()
+	if err != nil {
+		return fmt.Errorf("error finding the device name for loopback: %v", err)
+	}
+
+	// seeing if the user has already reserved some resources on this device
+	var nr *structs.NetworkResource
+	if conf.Node.Reserved == nil {
+		conf.Node.Reserved = &structs.Resources{}
+	}
+	for _, n := range conf.Node.Reserved.Networks {
+		if n.Device == deviceName {
+			nr = n
+		}
+	}
+	// If the user hasn't already created the device, we create it
+	if nr == nil {
+		nr = &structs.NetworkResource{
+			Device:        deviceName,
+			IP:            addr,
+			CIDR:          mask,
+			ReservedPorts: make([]structs.Port, 0),
+		}
+	}
+	// appending the port ranges we want to use for the client to the list of
+	// reserved ports for this device
+	for i := conf.ClientMinPort; i <= conf.ClientMaxPort; i++ {
+		nr.ReservedPorts = append(nr.ReservedPorts, structs.Port{Label: fmt.Sprintf("plugin-%d", i), Value: int(i)})
+	}
+	conf.Node.Reserved.Networks = append(conf.Node.Reserved.Networks, nr)
+	return nil
+}
+
+// findLoopbackDevice iterates through all the interfaces on a machine and
+// returns the ip addr, mask of the loopback device
+func (a *Agent) findLoopbackDevice() (string, string, string, error) {
 	var ifcs []net.Interface
 	var err error
-	var deviceName string
 	ifcs, err = net.Interfaces()
 	if err != nil {
-		return "", err
+		return "", "", "", err
 	}
 	for _, ifc := range ifcs {
 		addrs, err := ifc.Addrs()
 		if err != nil {
-			return deviceName, err
+			return "", "", "", err
 		}
 		for _, addr := range addrs {
-			if net.ParseIP(addr.String()).IsLoopback() {
-				return ifc.Name, nil
+			var ip net.IP
+			switch v := addr.(type) {
+			case *net.IPNet:
+				ip = v.IP
+			case *net.IPAddr:
+				ip = v.IP
+			}
+			if ip.IsLoopback() {
+				if ip.To4() == nil {
+					continue
+				}
+				return ifc.Name, ip.String(), addr.String(), nil
 			}
 		}
 	}
-	return deviceName, err
+
+	return "", "", "", fmt.Errorf("no loopback devices with IPV4 addr found")
 }
 
 // Leave is used gracefully exit. Clients will inform servers