kubeadm: make super-admin.conf changes to app/cmd

- Update unit tests in certs_test.go related to the "renew" CLI command.
- In /init, (d *initData) Client(), make sure that the new logic
for bootstrapping an "admin.conf" user is performed, by calling
EnsureAdminClusterRoleBinding() from the phases backend. Add a
"adminKubeConfigBootstrapped" flag that helps call this logic only
once per "kubeadm init" binary execution.
- In /phases/init include a new subphase for generating
the "super-admin.conf" file.
- In /phases/reset make sure the file "super-admin.conf" is
cleaned if present. Update unit tests.

cmd/kubeadm/app/cmd/certs_test.go

@@ -134,6 +134,7 @@ func TestRunRenewCommands(t *testing.T) {
 	// Generate all the kubeconfig files with embedded certs
 	for _, kubeConfig := range []string{
 		kubeadmconstants.AdminKubeConfigFileName,
+		kubeadmconstants.SuperAdminKubeConfigFileName,
 		kubeadmconstants.SchedulerKubeConfigFileName,
 		kubeadmconstants.ControllerManagerKubeConfigFileName,
 	} {
@@ -162,6 +163,7 @@ func TestRunRenewCommands(t *testing.T) {
 			},
 			KubeconfigFiles: []string{
 				kubeadmconstants.AdminKubeConfigFileName,
+				kubeadmconstants.SuperAdminKubeConfigFileName,
 				kubeadmconstants.SchedulerKubeConfigFileName,
 				kubeadmconstants.ControllerManagerKubeConfigFileName,
 			},
@@ -214,6 +216,12 @@ func TestRunRenewCommands(t *testing.T) {
 				kubeadmconstants.AdminKubeConfigFileName,
 			},
 		},
+		{
+			command: "super-admin.conf",
+			KubeconfigFiles: []string{
+				kubeadmconstants.SuperAdminKubeConfigFileName,
+			},
+		},
 		{
 			command: "scheduler.conf",
 			KubeconfigFiles: []string{

cmd/kubeadm/app/cmd/init.go

@@ -72,20 +72,21 @@ var _ phases.InitData = &initData{}
 // initData defines all the runtime information used when running the kubeadm init workflow;
 // this data is shared across all the phases that are included in the workflow.
 type initData struct {
-	cfg                     *kubeadmapi.InitConfiguration
-	skipTokenPrint          bool
-	dryRun                  bool
-	kubeconfigDir           string
-	kubeconfigPath          string
-	ignorePreflightErrors   sets.Set[string]
-	certificatesDir         string
-	dryRunDir               string
-	externalCA              bool
-	client                  clientset.Interface
-	outputWriter            io.Writer
-	uploadCerts             bool
-	skipCertificateKeyPrint bool
-	patchesDir              string
+	cfg                         *kubeadmapi.InitConfiguration
+	skipTokenPrint              bool
+	dryRun                      bool
+	kubeconfigDir               string
+	kubeconfigPath              string
+	ignorePreflightErrors       sets.Set[string]
+	certificatesDir             string
+	dryRunDir                   string
+	externalCA                  bool
+	client                      clientset.Interface
+	outputWriter                io.Writer
+	uploadCerts                 bool
+	skipCertificateKeyPrint     bool
+	patchesDir                  string
+	adminKubeConfigBootstrapped bool
 }
 
 // newCmdInit returns "kubeadm init" command.
@@ -495,12 +496,22 @@ func (d *initData) Client() (clientset.Interface, error) {
 			// If we're dry-running, we should create a faked client that answers some GETs in order to be able to do the full init flow and just logs the rest of requests
 			dryRunGetter := apiclient.NewInitDryRunGetter(d.cfg.NodeRegistration.Name, svcSubnetCIDR.String())
 			d.client = apiclient.NewDryRunClient(dryRunGetter, os.Stdout)
-		} else {
-			// If we're acting for real, we should create a connection to the API server and wait for it to come up
+		} else { // Use a real client
 			var err error
-			d.client, err = kubeconfigutil.ClientSetFromFile(d.KubeConfigPath())
-			if err != nil {
-				return nil, err
+			if !d.adminKubeConfigBootstrapped {
+				// Call EnsureAdminClusterRoleBinding() to obtain a working client from admin.conf.
+				d.client, err = kubeconfigphase.EnsureAdminClusterRoleBinding(kubeadmconstants.KubernetesDir, nil)
+				if err != nil {
+					return nil, errors.Wrapf(err, "could not bootstrap the admin user in file %s", kubeadmconstants.AdminKubeConfigFileName)
+				}
+				d.adminKubeConfigBootstrapped = true
+			} else {
+				// In case adminKubeConfigBootstrapped is already set just return a client from the default
+				// kubeconfig location.
+				d.client, err = kubeconfigutil.ClientSetFromFile(d.KubeConfigPath())
+				if err != nil {
+					return nil, err
+				}
 			}
 		}
 	}

cmd/kubeadm/app/cmd/phases/init/kubeconfig.go

@@ -41,6 +41,11 @@ var (
 			short: "Generate a kubeconfig file for the admin to use and for kubeadm itself",
 			long:  "Generate the kubeconfig file for the admin and for kubeadm itself, and save it to %s file.",
 		},
+		kubeadmconstants.SuperAdminKubeConfigFileName: {
+			name:  "super-admin",
+			short: "Generate a kubeconfig file for the super-admin",
+			long:  "Generate a kubeconfig file for the super-admin, and save it to %s file.",
+		},
 		kubeadmconstants.KubeletKubeConfigFileName: {
 			name:  "kubelet",
 			short: "Generate a kubeconfig file for the kubelet to use *only* for cluster bootstrapping purposes",
@@ -77,6 +82,7 @@ func NewKubeConfigPhase() workflow.Phase {
 				RunAllSiblings: true,
 			},
 			NewKubeConfigFilePhase(kubeadmconstants.AdminKubeConfigFileName),
+			NewKubeConfigFilePhase(kubeadmconstants.SuperAdminKubeConfigFileName),
 			NewKubeConfigFilePhase(kubeadmconstants.KubeletKubeConfigFileName),
 			NewKubeConfigFilePhase(kubeadmconstants.ControllerManagerKubeConfigFileName),
 			NewKubeConfigFilePhase(kubeadmconstants.SchedulerKubeConfigFileName),

cmd/kubeadm/app/cmd/phases/reset/cleanupnode.go

@@ -169,6 +169,7 @@ func resetConfigDir(configPathDir string, dirsToClean []string, isDryRun bool) {
 
 	filesToClean := []string{
 		filepath.Join(configPathDir, kubeadmconstants.AdminKubeConfigFileName),
+		filepath.Join(configPathDir, kubeadmconstants.SuperAdminKubeConfigFileName),
 		filepath.Join(configPathDir, kubeadmconstants.KubeletKubeConfigFileName),
 		filepath.Join(configPathDir, kubeadmconstants.KubeletBootstrapKubeConfigFileName),
 		filepath.Join(configPathDir, kubeadmconstants.ControllerManagerKubeConfigFileName),

cmd/kubeadm/app/cmd/phases/reset/cleanupnode_test.go

@@ -68,6 +68,7 @@ func TestConfigDirCleaner(t *testing.T) {
 				"manifests/kube-apiserver.yaml",
 				"pki/ca.pem",
 				kubeadmconstants.AdminKubeConfigFileName,
+				kubeadmconstants.SuperAdminKubeConfigFileName,
 				kubeadmconstants.KubeletKubeConfigFileName,
 			},
 			verifyExists: []string{