Add option to set a service nodeport

This patch adds the option to set a nodeport when creating a NodePort
service. In case of a port allocation error due to a specified port
being out of the valid range, the error now includes the valid
range. If a `--node-port` value is not specified, it defaults to zero, in
which case the allocator will default to its current behavior of
assigning an available port.

This patch also adds a new helper function in `cmd/util/helpers.go` to
retrieve `Int32` cobra flags.

**Example**
```
$ kubectl create service nodeport mynodeport --tcp=8080:7777 --node-port=1
The Service "mynodeport" is invalid: spec.ports[0].nodePort: Invalid
value: 1: provided port is not in the valid range. Valid ports range
from 30000-32767

$ kubectl create service nodeport mynodeport --tcp=8080:7777 --node-port=30000
service "mynodeport" created

$ oc describe service mynodeport
Name:                   mynodeport
Namespace:              default
Labels:                 app=mynodeport
Selector:               app=mynodeport
Type:                   NodePort
IP:                     172.30.81.254
Port:                   8080-7777       8080/TCP
NodePort:               8080-7777       30000/TCP
Endpoints:              <none>
Session Affinity:       None
No events.
```

pkg/kubectl/cmd/create_service.go

@@ -134,6 +134,7 @@ func NewCmdCreateServiceNodePort(f *cmdutil.Factory, cmdOut io.Writer) *cobra.Co
 	cmdutil.AddValidateFlags(cmd)
 	cmdutil.AddPrinterFlags(cmd)
 	cmdutil.AddGeneratorFlags(cmd, cmdutil.ServiceNodePortGeneratorV1Name)
+	cmd.Flags().Int32("node-port", 0, "Port used to expose the service on each node in a cluster.")
 	addPortFlags(cmd)
 	return cmd
 }
@@ -152,6 +153,7 @@ func CreateServiceNodePort(f *cmdutil.Factory, cmdOut io.Writer, cmd *cobra.Comm
 			TCP:       cmdutil.GetFlagStringSlice(cmd, "tcp"),
 			Type:      api.ServiceTypeNodePort,
 			ClusterIP: "",
+			NodePort:  cmdutil.GetFlagInt32(cmd, "node-port"),
 		}
 	default:
 		return cmdutil.UsageError(cmd, fmt.Sprintf("Generator: %s not supported.", generatorName))

pkg/kubectl/cmd/util/helpers.go

@@ -296,7 +296,7 @@ func isWatch(cmd *cobra.Command) bool {
 func GetFlagString(cmd *cobra.Command, flag string) string {
 	s, err := cmd.Flags().GetString(flag)
 	if err != nil {
-		glog.Fatalf("err accessing flag %s for command %s: %v", flag, cmd.Name(), err)
+		glog.Fatalf("error accessing flag %s for command %s: %v", flag, cmd.Name(), err)
 	}
 	return s
 }
@@ -305,7 +305,7 @@ func GetFlagString(cmd *cobra.Command, flag string) string {
 func GetFlagStringSlice(cmd *cobra.Command, flag string) []string {
 	s, err := cmd.Flags().GetStringSlice(flag)
 	if err != nil {
-		glog.Fatalf("err accessing flag %s for command %s: %v", flag, cmd.Name(), err)
+		glog.Fatalf("error accessing flag %s for command %s: %v", flag, cmd.Name(), err)
 	}
 	return s
 }
@@ -331,7 +331,7 @@ func GetWideFlag(cmd *cobra.Command) bool {
 func GetFlagBool(cmd *cobra.Command, flag string) bool {
 	b, err := cmd.Flags().GetBool(flag)
 	if err != nil {
-		glog.Fatalf("err accessing flag %s for command %s: %v", flag, cmd.Name(), err)
+		glog.Fatalf("error accessing flag %s for command %s: %v", flag, cmd.Name(), err)
 	}
 	return b
 }
@@ -340,7 +340,7 @@ func GetFlagBool(cmd *cobra.Command, flag string) bool {
 func GetFlagInt(cmd *cobra.Command, flag string) int {
 	i, err := cmd.Flags().GetInt(flag)
 	if err != nil {
-		glog.Fatalf("err accessing flag %s for command %s: %v", flag, cmd.Name(), err)
+		glog.Fatalf("error accessing flag %s for command %s: %v", flag, cmd.Name(), err)
 	}
 	return i
 }
@@ -349,7 +349,16 @@ func GetFlagInt(cmd *cobra.Command, flag string) int {
 func GetFlagInt64(cmd *cobra.Command, flag string) int64 {
 	i, err := cmd.Flags().GetInt64(flag)
 	if err != nil {
-		glog.Fatalf("err accessing flag %s for command %s: %v", flag, cmd.Name(), err)
+		glog.Fatalf("error accessing flag %s for command %s: %v", flag, cmd.Name(), err)
+	}
+	return i
+}
+
+// Assumes the flag has a default value.
+func GetFlagInt32(cmd *cobra.Command, flag string) int32 {
+	i, err := cmd.Flags().GetInt32(flag)
+	if err != nil {
+		glog.Fatalf("error accessing flag %s for command %s: %v", flag, cmd.Name(), err)
 	}
 	return i
 }
@@ -357,7 +366,7 @@ func GetFlagInt64(cmd *cobra.Command, flag string) int64 {
 func GetFlagDuration(cmd *cobra.Command, flag string) time.Duration {
 	d, err := cmd.Flags().GetDuration(flag)
 	if err != nil {
-		glog.Fatalf("err accessing flag %s for command %s: %v", flag, cmd.Name(), err)
+		glog.Fatalf("error accessing flag %s for command %s: %v", flag, cmd.Name(), err)
 	}
 	return d
 }

pkg/kubectl/service_basic.go

@@ -31,6 +31,7 @@ type ServiceCommonGeneratorV1 struct {
 	TCP       []string
 	Type      api.ServiceType
 	ClusterIP string
+	NodePort  int32
 }
 
 type ServiceClusterIPGeneratorV1 struct {
@@ -56,6 +57,7 @@ func (ServiceNodePortGeneratorV1) ParamNames() []GeneratorParam {
 	return []GeneratorParam{
 		{"name", true},
 		{"tcp", true},
+		{"nodeport", true},
 	}
 }
 func (ServiceLoadBalancerGeneratorV1) ParamNames() []GeneratorParam {
@@ -174,12 +176,14 @@ func (s ServiceCommonGeneratorV1) StructuredGenerate() (runtime.Object, error) {
 		if err != nil {
 			return nil, err
 		}
+
 		portName := strings.Replace(tcpString, ":", "-", -1)
 		ports = append(ports, api.ServicePort{
 			Name:       portName,
 			Port:       port,
 			TargetPort: targetPort,
 			Protocol:   api.Protocol("TCP"),
+			NodePort:   s.NodePort,
 		})
 	}
 

pkg/registry/core/service/portallocator/allocator.go

@@ -82,7 +82,10 @@ func (r *PortAllocator) Free() int {
 func (r *PortAllocator) Allocate(port int) error {
 	ok, offset := r.contains(port)
 	if !ok {
-		return ErrNotInRange
+		// include valid port range in error
+		validPorts := r.portRange.String()
+		msg := fmt.Sprintf("Valid ports range is %s", validPorts)
+		return fmt.Errorf("%v. %s", ErrNotInRange, msg)
 	}
 
 	allocated, err := r.alloc.Allocate(offset)