Merge pull request #33319 from juanvallejo/jvallejo/add-option-to-set-nodeport

Automatic merge from submit-queue

Add option to set a service nodeport

**Release note**:
```release-note
Add kubectl --node-port option for specifying the 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**
```
# create a nodeport service with an invalid port
$ 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

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

# create a nodeport service with a port already in use
$ kubectl create service nodeport mynodeport --tcp=8080:7777 --node-port=30000
The Service "mynodeport" is invalid: spec.ports[0].nodePort: Invalid value: 3000: provided port is already allocated

$ kubectl 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.
```

@fabianofranz

hack/verify-flags/known-flags.txt

@@ -384,6 +384,7 @@ node-monitor-period
 node-name
 node-os-distro
 node-path-override
+node-port
 node-startup-grace-period
 node-status-update-frequency
 node-sync-period

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().Int("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.GetFlagInt(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 +349,7 @@ 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
 }
@@ -357,7 +357,7 @@ 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  int
 }
 
 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:   int32(s.NodePort),
 		})
 	}
 

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

@@ -37,11 +37,18 @@ type Interface interface {
 
 var (
 	ErrFull              = errors.New("range is full")
-	ErrNotInRange        = errors.New("provided port is not in the valid range")
 	ErrAllocated         = errors.New("provided port is already allocated")
 	ErrMismatchedNetwork = errors.New("the provided port range does not match the current port range")
 )
 
+type ErrNotInRange struct {
+	ValidPorts string
+}
+
+func (e *ErrNotInRange) Error() string {
+	return fmt.Sprintf("provided port is not in the valid range. The range of valid ports is %s", e.ValidPorts)
+}
+
 type PortAllocator struct {
 	portRange net.PortRange
 
@@ -82,7 +89,9 @@ 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()
+		return &ErrNotInRange{validPorts}
 	}
 
 	allocated, err := r.alloc.Allocate(offset)

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

@@ -73,16 +73,23 @@ func TestAllocate(t *testing.T) {
 	if err := r.Release(released); err != nil {
 		t.Fatal(err)
 	}
-	if err := r.Allocate(1); err != ErrNotInRange {
+
+	err = r.Allocate(1)
+	if _, ok := err.(*ErrNotInRange); !ok {
 		t.Fatal(err)
 	}
+
 	if err := r.Allocate(10001); err != ErrAllocated {
 		t.Fatal(err)
 	}
-	if err := r.Allocate(20000); err != ErrNotInRange {
+
+	err = r.Allocate(20000)
+	if _, ok := err.(*ErrNotInRange); !ok {
 		t.Fatal(err)
 	}
-	if err := r.Allocate(10201); err != ErrNotInRange {
+
+	err = r.Allocate(10201)
+	if _, ok := err.(*ErrNotInRange); !ok {
 		t.Fatal(err)
 	}
 	if f := r.Free(); f != 1 {

pkg/registry/core/service/portallocator/controller/repair.go

@@ -114,7 +114,7 @@ func (c *Repair) runOnce() error {
 				// TODO: send event
 				// port is broken, reallocate
 				runtime.HandleError(fmt.Errorf("the port %d for service %s/%s was assigned to multiple services; please recreate", port, svc.Name, svc.Namespace))
-			case portallocator.ErrNotInRange:
+			case err.(*portallocator.ErrNotInRange):
 				// TODO: send event
 				// port is broken, reallocate
 				runtime.HandleError(fmt.Errorf("the port %d for service %s/%s is not within the port range %v; please recreate", port, svc.Name, svc.Namespace, c.portRange))