Qemu driver takes a port_map to configure host to guest port forwarding

client/driver/qemu.go

@@ -6,7 +6,6 @@ import (
 	"path/filepath"
 	"regexp"
 	"runtime"
-	"strconv"
 	"strings"
 	"time"
 
@@ -33,10 +32,10 @@ type QemuDriver struct {
 }
 
 type QemuDriverConfig struct {
-	ArtifactSource string `mapstructure:"artifact_source"`
-	Checksum       string `mapstructure:"checksum"`
-	Accelerator    string `mapstructure:"accelerator"`
-	GuestPorts     string `mapstructure:"guest_ports"`
+	ArtifactSource string           `mapstructure:"artifact_source"`
+	Checksum       string           `mapstructure:"checksum"`
+	Accelerator    string           `mapstructure:"accelerator"`
+	PortMap        []map[string]int `mapstructure:"port_map"` // A map of host port labels and to guest ports.
 }
 
 // qemuHandle is returned from Start/Open as a handle to the PID
@@ -82,6 +81,11 @@ func (d *QemuDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandle,
 	if err := mapstructure.WeakDecode(task.Config, &driverConfig); err != nil {
 		return nil, err
 	}
+
+	if len(driverConfig.PortMap) > 1 {
+		return nil, fmt.Errorf("Only one port_map block is allowed in the qemu driver config")
+	}
+
 	// Get the image source
 	source, ok := task.Config["artifact_source"]
 	if !ok || source == "" {
@@ -138,42 +142,31 @@ func (d *QemuDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandle,
 	// the outside world to be able to reach it. VMs ran without port mappings can
 	// still reach out to the world, but without port mappings it is effectively
 	// firewalled
-	if len(task.Resources.Networks) > 0 {
-		// TODO: Consolidate these into map of host/guest port when we have HCL
-		// Note: Host port must be open and available
-		// Get and split guest ports. The guest_ports configuration must match up with
-		// the Reserved ports in the Task Resources
-		// Users can supply guest_hosts as a list of posts to map on the guest vm.
-		// These map 1:1 with the requested Reserved Ports from the hostmachine.
-		ports := strings.Split(driverConfig.GuestPorts, ",")
-		if len(ports) == 0 {
-			return nil, fmt.Errorf("[ERR] driver.qemu: Error parsing required Guest Ports")
-		}
-
-		// TODO: support more than a single, default Network
-		if len(ports) != len(task.Resources.Networks[0].ReservedPorts) {
-			return nil, fmt.Errorf("[ERR] driver.qemu: Error matching Guest Ports with Reserved ports")
-		}
-
-		// Loop through the reserved ports and construct the hostfwd string, to map
+	protocols := []string{"udp", "tcp"}
+	if len(task.Resources.Networks) > 0 && len(driverConfig.PortMap) == 1 {
+		// Loop through the port map and construct the hostfwd string, to map
 		// reserved ports to the ports listenting in the VM
-		// Ex:
-		//    hostfwd=tcp::22000-:22,hostfwd=tcp::80-:8080
-		reservedPorts := task.Resources.Networks[0].ReservedPorts
-		var forwarding string
-		for i, p := range ports {
-			forwarding = fmt.Sprintf("%s,hostfwd=tcp::%s-:%s", forwarding, strconv.Itoa(reservedPorts[i].Value), p)
+		// Ex: hostfwd=tcp::22000-:22,hostfwd=tcp::80-:8080
+		var forwarding []string
+		taskPorts := task.Resources.Networks[0].MapLabelToValues()
+		for label, guest := range driverConfig.PortMap[0] {
+			host, ok := taskPorts[label]
+			if !ok {
+				return nil, fmt.Errorf("Unknown port label %q", label)
+			}
+
+			for _, p := range protocols {
+				forwarding = append(forwarding, fmt.Sprintf("hostfwd=%s::%d-:%d", p, host, guest))
+			}
 		}
 
-		if "" == forwarding {
-			return nil, fmt.Errorf("[ERR] driver.qemu:  Error constructing port forwarding")
+		if len(forwarding) != 0 {
+			args = append(args,
+				"-netdev",
+				fmt.Sprintf("user,id=user.0%s", strings.Join(forwarding, ",")),
+				"-device", "virtio-net,netdev=user.0",
+			)
 		}
-
-		args = append(args,
-			"-netdev",
-			fmt.Sprintf("user,id=user.0%s", forwarding),
-			"-device", "virtio-net,netdev=user.0",
-		)
 	}
 
 	// If using KVM, add optimization args

client/driver/qemu_test.go

@@ -41,7 +41,10 @@ func TestQemuDriver_StartOpen_Wait(t *testing.T) {
 			"artifact_source": "https://dl.dropboxusercontent.com/u/47675/jar_thing/linux-0.2.img",
 			"checksum":        "sha256:a5e836985934c3392cbbd9b26db55a7d35a8d7ae1deb7ca559dd9c0159572544",
 			"accelerator":     "tcg",
-			"guest_ports":     "22,8080",
+			"port_map": []map[string]int{{
+				"main": 22,
+				"web":  8080,
+			}},
 		},
 		Resources: &structs.Resources{
 			CPU:      500,