command: use correct port mapping syntax in examples

command/assets/example-short.nomad

@@ -3,7 +3,9 @@ job "example" {
 
   group "cache" {
     network {
-      port "db" {}
+      port "db" {
+        to = 6379
+      }
     }
 
     task "redis" {

command/assets/example.nomad

@@ -151,7 +151,9 @@ job "example" {
     #     https://www.nomadproject.io/docs/job-specification/network
     #
     network {
-      port "db" {}
+      port "db" {
+        to = 6379
+      }
     }
 
     # The "service" stanza instructs Nomad to register this task as a service

drivers/docker/driver.go

@@ -1095,6 +1095,9 @@ func (d *Driver) createContainerConfig(task *drivers.TaskConfig, driverConfig *T
 
 	default:
 		if len(driverConfig.PortMap) > 0 {
+			if task.Resources.Ports != nil {
+				return c, fmt.Errorf("'port_map' cannot map group network ports, use 'ports' instead")
+			}
 			return c, fmt.Errorf("Trying to map ports but no network interface is available")
 		}
 	}

plugins/drivers/utils_test.go

@@ -3,6 +3,8 @@ package drivers
 import (
 	"testing"
 
+	"github.com/hashicorp/nomad/helper/uuid"
+	"github.com/hashicorp/nomad/nomad/structs"
 	"github.com/stretchr/testify/require"
 )
 
@@ -32,3 +34,72 @@ func TestResourceUsageRoundTrip(t *testing.T) {
 
 	require.EqualValues(t, parsed, input)
 }
+
+func TestTaskConfigRoundTrip(t *testing.T) {
+
+	input := &TaskConfig{
+		ID:            uuid.Generate(),
+		Name:          "task",
+		JobName:       "job",
+		TaskGroupName: "group",
+		Resources: &Resources{
+			NomadResources: &structs.AllocatedTaskResources{
+				Cpu: structs.AllocatedCpuResources{
+					CpuShares: int64(100),
+				},
+				Memory: structs.AllocatedMemoryResources{
+					MemoryMB: int64(300),
+				},
+			},
+			LinuxResources: &LinuxResources{
+				MemoryLimitBytes: 300 * 1024 * 1024,
+				CPUShares:        100,
+				PercentTicks:     float64(100) / float64(3200),
+			},
+			Ports: &structs.AllocatedPorts{
+				{
+					Label:  "port",
+					Value:  23456,
+					To:     8080,
+					HostIP: "10.0.0.1",
+				},
+			},
+		},
+		Devices: []*DeviceConfig{
+			{
+				TaskPath:    "task",
+				HostPath:    "host",
+				Permissions: "perms",
+			},
+		},
+		Mounts: []*MountConfig{
+			{
+				TaskPath: "task",
+				HostPath: "host",
+				Readonly: true,
+			},
+		},
+		Env:        map[string]string{"gir": "zim"},
+		DeviceEnv:  map[string]string{"foo": "bar"},
+		User:       "user",
+		AllocDir:   "allocDir",
+		StdoutPath: "stdout",
+		StderrPath: "stderr",
+		AllocID:    uuid.Generate(),
+		NetworkIsolation: &NetworkIsolationSpec{
+			Mode:   NetIsolationModeGroup,
+			Path:   "path",
+			Labels: map[string]string{"net": "abc"},
+		},
+		DNS: &DNSConfig{
+			Servers:  []string{"8.8.8.8"},
+			Searches: []string{".consul"},
+			Options:  []string{"ndots:2"},
+		},
+	}
+
+	parsed := taskConfigFromProto(taskConfigToProto(input))
+
+	require.EqualValues(t, input, parsed)
+
+}