kubeadm-organize-phases

cmd/kubeadm/app/cmd/init.go

@@ -36,7 +36,7 @@ import (
 	kubeadmapiv1beta1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta1"
 	"k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/validation"
 	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/options"
-	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases"
+	phases "k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/init"
 	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow"
 	cmdutil "k8s.io/kubernetes/cmd/kubeadm/app/cmd/util"
 	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
@@ -168,7 +168,7 @@ func NewCmdInit(out io.Writer, initOptions *initOptions) *cobra.Command {
 	})
 
 	// initialize the workflow runner with the list of phases
-	initRunner.AppendPhase(phases.NewPreflightMasterPhase())
+	initRunner.AppendPhase(phases.NewPreflightPhase())
 	initRunner.AppendPhase(phases.NewKubeletStartPhase())
 	initRunner.AppendPhase(phases.NewCertsPhase())
 	initRunner.AppendPhase(phases.NewKubeConfigPhase())

cmd/kubeadm/app/cmd/join.go

@@ -38,7 +38,7 @@ import (
 	kubeadmapiv1beta1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta1"
 	"k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/validation"
 	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/options"
-	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases"
+	phases "k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/join"
 	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow"
 	cmdutil "k8s.io/kubernetes/cmd/kubeadm/app/cmd/util"
 	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
@@ -198,7 +198,7 @@ func NewCmdJoin(out io.Writer, joinOptions *joinOptions) *cobra.Command {
 	addJoinConfigFlags(cmd.Flags(), joinOptions.externalcfg)
 	addJoinOtherFlags(cmd.Flags(), &joinOptions.cfgPath, &joinOptions.ignorePreflightErrors, &joinOptions.controlPlane, &joinOptions.token)
 
-	joinRunner.AppendPhase(phases.NewPreflightJoinPhase())
+	joinRunner.AppendPhase(phases.NewPreflightPhase())
 	joinRunner.AppendPhase(phases.NewControlPlanePreparePhase())
 	joinRunner.AppendPhase(phases.NewCheckEtcdPhase())
 

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

@@ -0,0 +1,156 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package phases
+
+import (
+	"fmt"
+
+	"github.com/pkg/errors"
+
+	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
+	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/options"
+	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow"
+	cmdutil "k8s.io/kubernetes/cmd/kubeadm/app/cmd/util"
+	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
+	"k8s.io/kubernetes/cmd/kubeadm/app/phases/controlplane"
+	"k8s.io/kubernetes/pkg/util/normalizer"
+)
+
+var (
+	controlPlaneExample = normalizer.Examples(`
+		# Generates all static Pod manifest files for control plane components,
+		# functionally equivalent to what is generated by kubeadm init.
+		kubeadm init phase control-plane all
+
+		# Generates all static Pod manifest files using options read from a configuration file.
+		kubeadm init phase control-plane all --config config.yaml
+		`)
+
+	controlPlanePhaseProperties = map[string]struct {
+		name  string
+		short string
+	}{
+		kubeadmconstants.KubeAPIServer: {
+			name:  "apiserver",
+			short: getPhaseDescription(kubeadmconstants.KubeAPIServer),
+		},
+		kubeadmconstants.KubeControllerManager: {
+			name:  "controller-manager",
+			short: getPhaseDescription(kubeadmconstants.KubeControllerManager),
+		},
+		kubeadmconstants.KubeScheduler: {
+			name:  "scheduler",
+			short: getPhaseDescription(kubeadmconstants.KubeScheduler),
+		},
+	}
+)
+
+type controlPlaneData interface {
+	Cfg() *kubeadmapi.InitConfiguration
+	KubeConfigDir() string
+	ManifestDir() string
+}
+
+func getPhaseDescription(component string) string {
+	return fmt.Sprintf("Generates the %s static Pod manifest", component)
+}
+
+// NewControlPlanePhase creates a kubeadm workflow phase that implements bootstrapping the control plane.
+func NewControlPlanePhase() workflow.Phase {
+	phase := workflow.Phase{
+		Name:  "control-plane",
+		Short: "Generates all static Pod manifest files necessary to establish the control plane",
+		Long:  cmdutil.MacroCommandLongDescription,
+		Phases: []workflow.Phase{
+			{
+				Name:           "all",
+				Short:          "Generates all static Pod manifest files",
+				InheritFlags:   getControlPlanePhaseFlags("all"),
+				Example:        controlPlaneExample,
+				RunAllSiblings: true,
+			},
+			newControlPlaneSubphase(kubeadmconstants.KubeAPIServer),
+			newControlPlaneSubphase(kubeadmconstants.KubeControllerManager),
+			newControlPlaneSubphase(kubeadmconstants.KubeScheduler),
+		},
+		Run: runControlPlanePhase,
+	}
+	return phase
+}
+
+func newControlPlaneSubphase(component string) workflow.Phase {
+	phase := workflow.Phase{
+		Name:         controlPlanePhaseProperties[component].name,
+		Short:        controlPlanePhaseProperties[component].short,
+		Run:          runControlPlaneSubphase(component),
+		InheritFlags: getControlPlanePhaseFlags(component),
+	}
+	return phase
+}
+
+func getControlPlanePhaseFlags(name string) []string {
+	flags := []string{
+		options.CfgPath,
+		options.CertificatesDir,
+		options.KubernetesVersion,
+		options.ImageRepository,
+	}
+	if name == "all" || name == kubeadmconstants.KubeAPIServer {
+		flags = append(flags,
+			options.APIServerAdvertiseAddress,
+			options.APIServerBindPort,
+			options.APIServerExtraArgs,
+			options.FeatureGatesString,
+			options.NetworkingServiceSubnet,
+		)
+	}
+	if name == "all" || name == kubeadmconstants.KubeControllerManager {
+		flags = append(flags,
+			options.ControllerManagerExtraArgs,
+			options.NetworkingPodSubnet,
+		)
+	}
+	if name == "all" || name == kubeadmconstants.KubeScheduler {
+		flags = append(flags,
+			options.SchedulerExtraArgs,
+		)
+	}
+	return flags
+}
+
+func runControlPlanePhase(c workflow.RunData) error {
+	data, ok := c.(controlPlaneData)
+	if !ok {
+		return errors.New("control-plane phase invoked with an invalid data struct")
+	}
+
+	fmt.Printf("[control-plane] Using manifest folder %q\n", data.ManifestDir())
+	return nil
+}
+
+func runControlPlaneSubphase(component string) func(c workflow.RunData) error {
+	return func(c workflow.RunData) error {
+		data, ok := c.(controlPlaneData)
+		if !ok {
+			return errors.New("control-plane phase invoked with an invalid data struct")
+		}
+		cfg := data.Cfg()
+
+		fmt.Printf("[control-plane] Creating static Pod manifest for %q\n", component)
+		return controlplane.CreateStaticPodFiles(data.ManifestDir(), &cfg.ClusterConfiguration, &cfg.LocalAPIEndpoint, component)
+	}
+}

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

@@ -0,0 +1,87 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package phases
+
+import (
+	"fmt"
+
+	"github.com/pkg/errors"
+	"k8s.io/apimachinery/pkg/util/sets"
+	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
+	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/options"
+	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow"
+	"k8s.io/kubernetes/cmd/kubeadm/app/preflight"
+	"k8s.io/kubernetes/pkg/util/normalizer"
+	utilsexec "k8s.io/utils/exec"
+)
+
+var (
+	preflightExample = normalizer.Examples(`
+		# Run pre-flight checks for kubeadm init using a config file.
+		kubeadm init phase preflight --config kubeadm-config.yml
+		`)
+)
+
+// preflightData defines the behavior that a runtime data struct passed to the Preflight phase
+// should have. Please note that we are using an interface in order to make this phase reusable in different workflows
+// (and thus with different runtime data struct, all of them requested to be compliant to this interface)
+type preflightData interface {
+	Cfg() *kubeadmapi.InitConfiguration
+	DryRun() bool
+	IgnorePreflightErrors() sets.String
+}
+
+// NewPreflightPhase creates a kubeadm workflow phase that implements preflight checks for a new control-plane node.
+func NewPreflightPhase() workflow.Phase {
+	return workflow.Phase{
+		Name:    "preflight",
+		Short:   "Run pre-flight checks",
+		Long:    "Run pre-flight checks for kubeadm init.",
+		Example: preflightExample,
+		Run:     runPreflight,
+		InheritFlags: []string{
+			options.CfgPath,
+			options.IgnorePreflightErrors,
+		},
+	}
+}
+
+// runPreflight executes preflight checks logic.
+func runPreflight(c workflow.RunData) error {
+	data, ok := c.(preflightData)
+	if !ok {
+		return errors.New("preflight phase invoked with an invalid data struct")
+	}
+
+	fmt.Println("[preflight] Running pre-flight checks")
+	if err := preflight.RunInitMasterChecks(utilsexec.New(), data.Cfg(), data.IgnorePreflightErrors()); err != nil {
+		return err
+	}
+
+	if !data.DryRun() {
+		fmt.Println("[preflight] Pulling images required for setting up a Kubernetes cluster")
+		fmt.Println("[preflight] This might take a minute or two, depending on the speed of your internet connection")
+		fmt.Println("[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'")
+		if err := preflight.RunPullImagesCheck(utilsexec.New(), data.Cfg(), data.IgnorePreflightErrors()); err != nil {
+			return err
+		}
+	} else {
+		fmt.Println("[preflight] Would pull the required images (like 'kubeadm config images pull')")
+	}
+
+	return nil
+}

cmd/kubeadm/app/cmd/phases/join/controlplane.go

@@ -30,77 +30,14 @@ import (
 	certsphase "k8s.io/kubernetes/cmd/kubeadm/app/phases/certs"
 	"k8s.io/kubernetes/cmd/kubeadm/app/phases/controlplane"
 	kubeconfigphase "k8s.io/kubernetes/cmd/kubeadm/app/phases/kubeconfig"
-	"k8s.io/kubernetes/pkg/util/normalizer"
 )
 
-var (
-	controlPlaneExample = normalizer.Examples(`
-		# Generates all static Pod manifest files for control plane components,
-		# functionally equivalent to what is generated by kubeadm init.
-		kubeadm init phase control-plane all
-
-		# Generates all static Pod manifest files using options read from a configuration file.
-		kubeadm init phase control-plane all --config config.yaml
-		`)
-
-	controlPlanePhaseProperties = map[string]struct {
-		name  string
-		short string
-	}{
-		kubeadmconstants.KubeAPIServer: {
-			name:  "apiserver",
-			short: getPhaseDescription(kubeadmconstants.KubeAPIServer),
-		},
-		kubeadmconstants.KubeControllerManager: {
-			name:  "controller-manager",
-			short: getPhaseDescription(kubeadmconstants.KubeControllerManager),
-		},
-		kubeadmconstants.KubeScheduler: {
-			name:  "scheduler",
-			short: getPhaseDescription(kubeadmconstants.KubeScheduler),
-		},
-	}
-)
-
-type controlPlaneData interface {
-	Cfg() *kubeadmapi.InitConfiguration
-	KubeConfigDir() string
-	ManifestDir() string
-}
-
 type controlPlanePrepareData interface {
 	Cfg() *kubeadmapi.JoinConfiguration
 	ClientSetFromFile(string) (*clientset.Clientset, error)
 	InitCfg() (*kubeadmapi.InitConfiguration, error)
 }
 
-func getPhaseDescription(component string) string {
-	return fmt.Sprintf("Generates the %s static Pod manifest", component)
-}
-
-// NewControlPlanePhase creates a kubeadm workflow phase that implements bootstrapping the control plane.
-func NewControlPlanePhase() workflow.Phase {
-	phase := workflow.Phase{
-		Name:  "control-plane",
-		Short: "Generates all static Pod manifest files necessary to establish the control plane",
-		Long:  cmdutil.MacroCommandLongDescription,
-		Phases: []workflow.Phase{
-			{
-				Name:           "all",
-				Short:          "Generates all static Pod manifest files",
-				InheritFlags:   getControlPlanePhaseFlags("all"),
-				Example:        controlPlaneExample,
-				RunAllSiblings: true,
-			},
-			newControlPlaneSubphase(kubeadmconstants.KubeAPIServer),
-			newControlPlaneSubphase(kubeadmconstants.KubeControllerManager),
-			newControlPlaneSubphase(kubeadmconstants.KubeScheduler),
-		},
-		Run: runControlPlanePhase,
-	}
-	return phase
-}
-
 // NewControlPlanePreparePhase creates a kubeadm workflow phase that implements the preparation of the node to serve a control plane
 func NewControlPlanePreparePhase() workflow.Phase {
 	return workflow.Phase{
@@ -108,6 +45,12 @@ func NewControlPlanePreparePhase() workflow.Phase {
 		Short: "Prepares the machine for serving a control plane.",
 		Long:  cmdutil.MacroCommandLongDescription,
 		Phases: []workflow.Phase{
+			{
+				Name:           "all",
+				Short:          "Prepares the machine for serving a control plane.",
+				InheritFlags:   getControlPlanePreparePhaseFlags(),
+				RunAllSiblings: true,
+			},
 			newControlPlanePrepareCertsSubphase(),
 			newControlPlanePrepareKubeconfigSubphase(),
 			newControlPlanePrepareManifestsSubphases(),
@@ -115,46 +58,6 @@ func NewControlPlanePreparePhase() workflow.Phase {
 	}
 }
 
-func newControlPlaneSubphase(component string) workflow.Phase {
-	phase := workflow.Phase{
-		Name:         controlPlanePhaseProperties[component].name,
-		Short:        controlPlanePhaseProperties[component].short,
-		Run:          runControlPlaneSubphase(component),
-		InheritFlags: getControlPlanePhaseFlags(component),
-	}
-	return phase
-}
-
-func getControlPlanePhaseFlags(name string) []string {
-	flags := []string{
-		options.CfgPath,
-		options.CertificatesDir,
-		options.KubernetesVersion,
-		options.ImageRepository,
-	}
-	if name == "all" || name == kubeadmconstants.KubeAPIServer {
-		flags = append(flags,
-			options.APIServerAdvertiseAddress,
-			options.APIServerBindPort,
-			options.APIServerExtraArgs,
-			options.FeatureGatesString,
-			options.NetworkingServiceSubnet,
-		)
-	}
-	if name == "all" || name == kubeadmconstants.KubeControllerManager {
-		flags = append(flags,
-			options.ControllerManagerExtraArgs,
-			options.NetworkingPodSubnet,
-		)
-	}
-	if name == "all" || name == kubeadmconstants.KubeScheduler {
-		flags = append(flags,
-			options.SchedulerExtraArgs,
-		)
-	}
-	return flags
-}
-
 func getControlPlanePreparePhaseFlags() []string {
 	return []string{
 		options.APIServerAdvertiseAddress,
@@ -173,7 +76,7 @@ func newControlPlanePrepareCertsSubphase() workflow.Phase {
 		Name:         "certs",
 		Short:        "Generates the certificates for the new control plane components",
 		Run:          runControlPlanePrepareCertsPhaseLocal,
-		InheritFlags: getControlPlanePreparePhaseFlags(),
+		InheritFlags: getControlPlanePreparePhaseFlags(), //NB. eventually in future we would like to break down this in sub phases for each cert or add the --csr option
 	}
 }
 
@@ -182,7 +85,7 @@ func newControlPlanePrepareKubeconfigSubphase() workflow.Phase {
 		Name:         "kubeconfig",
 		Short:        "Generates the kubeconfig for the new control plane components",
 		Run:          runControlPlanePrepareKubeconfigPhaseLocal,
-		InheritFlags: getControlPlanePreparePhaseFlags(),
+		InheritFlags: getControlPlanePreparePhaseFlags(), //NB. eventually in future we would like to break down this in sub phases for each kubeconfig
 	}
 }
 
@@ -190,51 +93,29 @@ func newControlPlanePrepareManifestsSubphases() workflow.Phase {
 	return workflow.Phase{
 		Name:         "manifests",
 		Short:        "Generates the manifests for the new control plane components",
-		Phases: []workflow.Phase{
-			{
-				Name:           "all",
-				Short:          "Generates all static Pod manifest files",
-				InheritFlags:   getControlPlanePreparePhaseFlags(),
-				RunAllSiblings: true,
-			},
-			newControlPlanePrepareSubphase(kubeadmconstants.KubeAPIServer),
-			newControlPlanePrepareSubphase(kubeadmconstants.KubeControllerManager),
-			newControlPlanePrepareSubphase(kubeadmconstants.KubeScheduler),
-		},
-		InheritFlags: getControlPlanePreparePhaseFlags(),
+		Run:          runControlPlaneSubphase,
+		InheritFlags: getControlPlanePreparePhaseFlags(), //NB. eventually in future we would like to break down this in sub phases for each component
 	}
 }
 
-func newControlPlanePrepareSubphase(component string) workflow.Phase {
-	return workflow.Phase{
-		Name:         controlPlanePhaseProperties[component].name,
-		Short:        controlPlanePhaseProperties[component].short,
-		Run:          runControlPlanePrepareJoinSubphase(component),
-		InheritFlags: getControlPlanePreparePhaseFlags(),
-	}
-}
-
-func runControlPlanePhase(c workflow.RunData) error {
-	data, ok := c.(controlPlaneData)
+func runControlPlaneSubphase(c workflow.RunData) error {
+	data, ok := c.(controlPlanePrepareData)
 	if !ok {
-		return errors.New("control-plane phase invoked with an invalid data struct")
+		return errors.New("control-plane-prepare phase invoked with an invalid data struct")
 	}
 
-	fmt.Printf("[control-plane] Using manifest folder %q\n", data.ManifestDir())
+	// Skip if this is not a control plane
+	if data.Cfg().ControlPlane == nil {
 		return nil
 	}
 
-func runControlPlaneSubphase(component string) func(c workflow.RunData) error {
-	return func(c workflow.RunData) error {
-		data, ok := c.(controlPlaneData)
-		if !ok {
-			return errors.New("control-plane phase invoked with an invalid data struct")
+	cfg, err := data.InitCfg()
+	if err != nil {
+		return err
 	}
-		cfg := data.Cfg()
 
-		fmt.Printf("[control-plane] Creating static Pod manifest for %q\n", component)
-		return controlplane.CreateStaticPodFiles(data.ManifestDir(), &cfg.ClusterConfiguration, &cfg.LocalAPIEndpoint, component)
-	}
+	// Generate missing certificates (if any)
+	return controlplane.CreateInitStaticPodManifestFiles(kubeadmconstants.GetStaticPodDirectory(), cfg)
 }
 
 func runControlPlanePrepareCertsPhaseLocal(c workflow.RunData) error {

cmd/kubeadm/app/cmd/phases/join/preflight.go

@@ -35,11 +35,7 @@ import (
 )
 
 var (
-	initPreflightExample = normalizer.Examples(`
-		# Run master pre-flight checks using a config file.
-		kubeadm init phase preflight --config kubeadm-config.yml
-		`)
-	joinPreflightExample = normalizer.Examples(`
+	preflightExample = normalizer.Examples(`
 		# Run join pre-flight checks using a config file.
 		kubeadm join phase preflight --config kubeadm-config.yml
 		`)
@@ -56,71 +52,20 @@ var (
 		`)))
 )
 
-// preflightMasterData defines the behavior that a runtime data struct passed to the PreflightMaster master phase
-// should have. Please note that we are using an interface in order to make this phase reusable in different workflows
-// (and thus with different runtime data struct, all of them requested to be compliant to this interface)
-type preflightMasterData interface {
-	Cfg() *kubeadmapi.InitConfiguration
-	DryRun() bool
-	IgnorePreflightErrors() sets.String
-}
-
-type preflightJoinData interface {
+type preflightData interface {
 	Cfg() *kubeadmapi.JoinConfiguration
 	InitCfg() (*kubeadmapi.InitConfiguration, error)
 	IgnorePreflightErrors() sets.String
 }
 
-// NewPreflightMasterPhase creates a kubeadm workflow phase that implements preflight checks for a new master node.
-func NewPreflightMasterPhase() workflow.Phase {
-	return workflow.Phase{
-		Name:    "preflight",
-		Short:   "Run master pre-flight checks",
-		Long:    "Run master pre-flight checks, functionally equivalent to what implemented by kubeadm init.",
-		Example: initPreflightExample,
-		Run:     runPreflightMaster,
-		InheritFlags: []string{
-			options.CfgPath,
-			options.IgnorePreflightErrors,
-		},
-	}
-}
-
-// TODO(dmaiocchi):  rename all instances of master to controlPlane in this file.
-// runPreflightMaster executes preflight checks logic.
-func runPreflightMaster(c workflow.RunData) error {
-	data, ok := c.(preflightMasterData)
-	if !ok {
-		return errors.New("preflight phase invoked with an invalid data struct")
-	}
-
-	fmt.Println("[preflight] Running pre-flight checks")
-	if err := preflight.RunInitMasterChecks(utilsexec.New(), data.Cfg(), data.IgnorePreflightErrors()); err != nil {
-		return err
-	}
-
-	if !data.DryRun() {
-		fmt.Println("[preflight] Pulling images required for setting up a Kubernetes cluster")
-		fmt.Println("[preflight] This might take a minute or two, depending on the speed of your internet connection")
-		fmt.Println("[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'")
-		if err := preflight.RunPullImagesCheck(utilsexec.New(), data.Cfg(), data.IgnorePreflightErrors()); err != nil {
-			return err
-		}
-	} else {
-		fmt.Println("[preflight] Would pull the required images (like 'kubeadm config images pull')")
-	}
-
-	return nil
-}
-
-// NewPreflightJoinPhase creates a kubeadm workflow phase that implements preflight checks for a new node join
-func NewPreflightJoinPhase() workflow.Phase {
+// NewPreflightPhase creates a kubeadm workflow phase that implements preflight checks for a new node join
+func NewPreflightPhase() workflow.Phase {
 	return workflow.Phase{
 		Name:    "preflight",
 		Short:   "Run join pre-flight checks",
-		Long:    "Run join pre-flight checks, functionally equivalent to what is implemented by kubeadm join.",
-		Example: joinPreflightExample,
-		Run:     runPreflightJoin,
+		Long:    "Run pre-flight checks for kubeadm join.",
+		Example: preflightExample,
+		Run:     runPreflight,
 		InheritFlags: []string{
 			options.CfgPath,
 			options.IgnorePreflightErrors,
@@ -139,12 +84,14 @@ func NewPreflightJoinPhase() workflow.Phase {
 	}
 }
 
-// runPreflightJoin executes preflight checks logic.
-func runPreflightJoin(c workflow.RunData) error {
-	j, ok := c.(preflightJoinData)
+// runPreflight executes preflight checks logic.
+func runPreflight(c workflow.RunData) error {
+	j, ok := c.(preflightData)
 	if !ok {
 		return errors.New("preflight phase invoked with an invalid data struct")
 	}
+	fmt.Println("[preflight] Running pre-flight checks")
+
 	// Start with general checks
 	klog.V(1).Infoln("[preflight] Running general checks")
 	if err := preflight.RunJoinNodeChecks(utilsexec.New(), j.Cfg(), j.IgnorePreflightErrors()); err != nil {
@@ -182,7 +129,9 @@ func runPreflightJoin(c workflow.RunData) error {
 			return err
 		}
 
-		fmt.Println("[preflight] Pulling control-plane images")
+		fmt.Println("[preflight] Pulling images required for setting up a Kubernetes cluster")
+		fmt.Println("[preflight] This might take a minute or two, depending on the speed of your internet connection")
+		fmt.Println("[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'")
 		if err := preflight.RunPullImagesCheck(utilsexec.New(), initCfg, j.IgnorePreflightErrors()); err != nil {
 			return err
 		}