Merge pull request #46283 from ktsakalozos/feature/nodeport-port

Automatic merge from submit-queue

Adding option to set the federation api server port if nodeport is set

**What this PR does / why we need it**: Kubefed will deploy the respected services and then it will do a health check. Prior to this patch if the user selects the nodeport a random port is opened. In environments where firewalls are in place this random port selection will cause the health check to fail. With this patch we enable users to designate a specific port, after for example opening it on their firewall.    

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #46021

**Special notes for your reviewer**:

**Release note**: 

```
Kubefed init allows for setting port in Nodeport configuration
```

federation/pkg/kubefed/init/init.go

@@ -84,6 +84,7 @@ const (
 
 	apiserverServiceTypeFlag      = "api-server-service-type"
 	apiserverAdvertiseAddressFlag = "api-server-advertise-address"
+	apiserverPortFlag             = "api-server-port"
 
 	dnsProviderSecretName = "federation-dns-provider.conf"
 
@@ -149,6 +150,8 @@ type initFederationOptions struct {
 	apiServerServiceTypeString       string
 	apiServerServiceType             v1.ServiceType
 	apiServerAdvertiseAddress        string
+	apiServerNodePortPort            int32
+	apiServerNodePortPortPtr         *int32
 	apiServerEnableHTTPBasicAuth     bool
 	apiServerEnableTokenAuth         bool
 }
@@ -167,6 +170,7 @@ func (o *initFederationOptions) Bind(flags *pflag.FlagSet, defaultServerImage, d
 	flags.StringVar(&o.controllerManagerOverridesString, "controllermanager-arg-overrides", "", "comma separated list of federation-controller-manager arguments to override: Example \"--arg1=value1,--arg2=value2...\"")
 	flags.StringVar(&o.apiServerServiceTypeString, apiserverServiceTypeFlag, string(v1.ServiceTypeLoadBalancer), "The type of service to create for federation API server. Options: 'LoadBalancer' (default), 'NodePort'.")
 	flags.StringVar(&o.apiServerAdvertiseAddress, apiserverAdvertiseAddressFlag, "", "Preferred address to advertise api server nodeport service. Valid only if '"+apiserverServiceTypeFlag+"=NodePort'.")
+	flags.Int32Var(&o.apiServerNodePortPort, apiserverPortFlag, 0, "Preferred port to use for api server nodeport service (0 for random port assignment). Valid only if '"+apiserverServiceTypeFlag+"=NodePort'.")
 	flags.BoolVar(&o.apiServerEnableHTTPBasicAuth, "apiserver-enable-basic-auth", false, "Enables HTTP Basic authentication for the federation-apiserver. Defaults to false.")
 	flags.BoolVar(&o.apiServerEnableTokenAuth, "apiserver-enable-token-auth", false, "Enables token authentication for the federation-apiserver. Defaults to false.")
 }
@@ -233,6 +237,18 @@ func (i *initFederation) Complete(cmd *cobra.Command, args []string) error {
 		}
 	}
 
+	if i.options.apiServerNodePortPort != 0 {
+		if i.options.apiServerServiceType != v1.ServiceTypeNodePort {
+			return fmt.Errorf("%s should be passed only with '%s=NodePort'", apiserverPortFlag, apiserverServiceTypeFlag)
+		}
+		i.options.apiServerNodePortPortPtr = &i.options.apiServerNodePortPort
+	} else {
+		i.options.apiServerNodePortPortPtr = nil
+	}
+	if i.options.apiServerNodePortPort < 0 || i.options.apiServerNodePortPort > 65535 {
+		return fmt.Errorf("Please provide a valid port number for %s", apiserverPortFlag)
+	}
+
 	i.options.apiServerOverrides, err = marshallOverrides(i.options.apiServerOverridesString)
 	if err != nil {
 		return fmt.Errorf("error marshalling --apiserver-arg-overrides: %v", err)
@@ -296,7 +312,7 @@ func (i *initFederation) Run(cmdOut io.Writer, config util.AdminConfig) error {
 
 	fmt.Fprint(cmdOut, "Creating federation control plane service...")
 	glog.V(4).Info("Creating federation control plane service")
-	svc, ips, hostnames, err := createService(cmdOut, hostClientset, i.commonOptions.FederationSystemNamespace, serverName, i.commonOptions.Name, i.options.apiServerAdvertiseAddress, i.options.apiServerServiceType, i.options.dryRun)
+	svc, ips, hostnames, err := createService(cmdOut, hostClientset, i.commonOptions.FederationSystemNamespace, serverName, i.commonOptions.Name, i.options.apiServerAdvertiseAddress, i.options.apiServerNodePortPortPtr, i.options.apiServerServiceType, i.options.dryRun)
 	if err != nil {
 		return err
 	}
@@ -446,7 +462,16 @@ func createNamespace(clientset client.Interface, federationName, namespace strin
 	return clientset.Core().Namespaces().Create(ns)
 }
 
-func createService(cmdOut io.Writer, clientset client.Interface, namespace, svcName, federationName, apiserverAdvertiseAddress string, apiserverServiceType v1.ServiceType, dryRun bool) (*api.Service, []string, []string, error) {
+func createService(cmdOut io.Writer, clientset client.Interface, namespace, svcName, federationName, apiserverAdvertiseAddress string, apiserverPort *int32, apiserverServiceType v1.ServiceType, dryRun bool) (*api.Service, []string, []string, error) {
+	port := api.ServicePort{
+		Name:       "https",
+		Protocol:   "TCP",
+		Port:       443,
+		TargetPort: intstr.FromString(apiServerSecurePortName),
+	}
+	if apiserverServiceType == v1.ServiceTypeNodePort && apiserverPort != nil {
+		port.NodePort = *apiserverPort
+	}
 	svc := &api.Service{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:        svcName,
@@ -457,14 +482,7 @@ func createService(cmdOut io.Writer, clientset client.Interface, namespace, svcN
 		Spec: api.ServiceSpec{
 			Type:     api.ServiceType(apiserverServiceType),
 			Selector: apiserverSvcSelector,
-			Ports: []api.ServicePort{
+			Ports:    []api.ServicePort{port},
-				{
-					Name:       "https",
-					Protocol:   "TCP",
-					Port:       443,
-					TargetPort: intstr.FromString(apiServerSecurePortName),
-				},
-			},
 		},
 	}
 
@@ -474,6 +492,9 @@ func createService(cmdOut io.Writer, clientset client.Interface, namespace, svcN
 
 	var err error
 	svc, err = clientset.Core().Services(namespace).Create(svc)
+	if err != nil {
+		return nil, nil, nil, err
+	}
 
 	ips := []string{}
 	hostnames := []string{}