Merge pull request #134319 from neolit123/1.35-refactor-fetch-init-config-flags

kubeadm: rework the FetchInitConfigurationFromCluster node flags

cmd/kubeadm/app/cmd/certs.go

@@ -49,6 +49,7 @@ import (
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/errors"
 	kubeconfigutil "k8s.io/kubernetes/cmd/kubeadm/app/util/kubeconfig"
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/output"
+	staticpodutil "k8s.io/kubernetes/cmd/kubeadm/app/util/staticpod"
 )
 
 var (
@@ -346,7 +347,10 @@ func getInternalCfg(cfgPath string, client kubernetes.Interface, cfg kubeadmapiv
 	// In case the user is not providing a custom config, try to get current config from the cluster.
 	// NB. this operation should not block, because we want to allow certificate renewal also in case of not-working clusters
 	if cfgPath == "" && client != nil {
-		internalcfg, err := configutil.FetchInitConfigurationFromCluster(client, printer, logPrefix, false, false)
+		getNodeRegistration := true
+		getAPIEndpoint := staticpodutil.IsControlPlaneNode()
+		getComponentConfigs := true
+		internalcfg, err := configutil.FetchInitConfigurationFromCluster(client, printer, logPrefix, getNodeRegistration, getAPIEndpoint, getComponentConfigs)
 		if err == nil {
 			printer.Println() // add empty line to separate the FetchInitConfigurationFromCluster output from the command output
 			// certificate renewal or expiration checking doesn't depend on a running cluster, which means the CertificatesDir

cmd/kubeadm/app/cmd/join.go

@@ -709,7 +709,10 @@ func fetchInitConfigurationFromJoinConfiguration(cfg *kubeadmapi.JoinConfigurati
 
 // fetchInitConfiguration reads the cluster configuration from the kubeadm-admin configMap
 func fetchInitConfiguration(client clientset.Interface) (*kubeadmapi.InitConfiguration, error) {
-	initConfiguration, err := configutil.FetchInitConfigurationFromCluster(client, nil, "preflight", true, false)
+	getNodeRegistration := false
+	getAPIEndpoint := false
+	getComponentConfigs := true
+	initConfiguration, err := configutil.FetchInitConfigurationFromCluster(client, nil, "preflight", getNodeRegistration, getAPIEndpoint, getComponentConfigs)
 	if err != nil {
 		return nil, errors.Wrap(err, "unable to fetch the kubeadm-config ConfigMap")
 	}

cmd/kubeadm/app/cmd/reset.go

@@ -44,6 +44,7 @@ import (
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/errors"
 	kubeconfigutil "k8s.io/kubernetes/cmd/kubeadm/app/util/kubeconfig"
 	utilruntime "k8s.io/kubernetes/cmd/kubeadm/app/util/runtime"
+	staticpodutil "k8s.io/kubernetes/cmd/kubeadm/app/util/staticpod"
 )
 
 var (
@@ -132,7 +133,10 @@ func newResetData(cmd *cobra.Command, opts *resetOptions, in io.Reader, out io.W
 
 	if err == nil {
 		klog.V(1).Infof("[reset] Loaded client set from kubeconfig file: %s", opts.kubeconfigPath)
-		initCfg, err = configutil.FetchInitConfigurationFromCluster(client, nil, "reset", false, false)
+		getNodeRegistration := true
+		getAPIEndpoint := staticpodutil.IsControlPlaneNode()
+		getComponentConfigs := true
+		initCfg, err = configutil.FetchInitConfigurationFromCluster(client, nil, "reset", getNodeRegistration, getAPIEndpoint, getComponentConfigs)
 		if err != nil {
 			klog.Warningf("[reset] Unable to fetch the kubeadm-config ConfigMap from cluster: %v", err)
 		}

cmd/kubeadm/app/cmd/upgrade/apply.go

@@ -238,7 +238,10 @@ func newApplyData(cmd *cobra.Command, args []string, applyFlags *applyFlags) (*a
 
 	// Fetches the cluster configuration.
 	klog.V(1).Infoln("[upgrade] retrieving configuration from cluster")
-	initCfg, err := configutil.FetchInitConfigurationFromCluster(client, nil, "upgrade", false, false)
+	getNodeRegistration := true
+	isControlPlaneNode := true
+	getComponentConfigs := true
+	initCfg, err := configutil.FetchInitConfigurationFromCluster(client, nil, "upgrade", getNodeRegistration, isControlPlaneNode, getComponentConfigs)
 	if err != nil {
 		if apierrors.IsNotFound(err) {
 			_, _ = printer.Printf("[upgrade] In order to upgrade, a ConfigMap called %q in the %q namespace must exist.\n", constants.KubeadmConfigConfigMap, metav1.NamespaceSystem)

cmd/kubeadm/app/cmd/upgrade/common.go

@@ -45,6 +45,7 @@ import (
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/errors"
 	kubeconfigutil "k8s.io/kubernetes/cmd/kubeadm/app/util/kubeconfig"
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/output"
+	staticpodutil "k8s.io/kubernetes/cmd/kubeadm/app/util/staticpod"
 )
 
 // enforceRequirements verifies that it's okay to upgrade and then returns the variables needed for the rest of the procedure
@@ -92,7 +93,10 @@ func enforceRequirements(flagSet *pflag.FlagSet, flags *applyPlanFlags, args []s
 		return nil, nil, nil, nil, err
 	}
 
-	initCfg, err := configutil.FetchInitConfigurationFromCluster(client, printer, "upgrade/config", false, false)
+	getNodeRegistration := true
+	getAPIEndpoint := staticpodutil.IsControlPlaneNode()
+	getComponentConfigs := true
+	initCfg, err := configutil.FetchInitConfigurationFromCluster(client, printer, "upgrade/config", getNodeRegistration, getAPIEndpoint, getComponentConfigs)
 	if err != nil {
 		return nil, nil, nil, nil, errors.Wrap(err, "[upgrade/init config] FATAL")
 	}

cmd/kubeadm/app/cmd/upgrade/diff.go

@@ -41,6 +41,7 @@ import (
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/errors"
 	kubeconfigutil "k8s.io/kubernetes/cmd/kubeadm/app/util/kubeconfig"
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/output"
+	staticpodutil "k8s.io/kubernetes/cmd/kubeadm/app/util/staticpod"
 )
 
 type diffFlags struct {
@@ -106,7 +107,7 @@ func validateManifestsPath(manifests ...string) (err error) {
 }
 
 // FetchInitConfigurationFunc defines the signature of the function which will fetch InitConfiguration from cluster.
-type FetchInitConfigurationFunc func(client clientset.Interface, printer output.Printer, logPrefix string, newControlPlane, skipComponentConfigs bool) (*kubeadmapi.InitConfiguration, error)
+type FetchInitConfigurationFunc func(client clientset.Interface, printer output.Printer, logPrefix string, getNodeRegistration, getAPIEndpoint, getComponentConfigs bool) (*kubeadmapi.InitConfiguration, error)
 
 func runDiff(fs *pflag.FlagSet, flags *diffFlags, args []string, fetchInitConfigurationFromCluster FetchInitConfigurationFunc) error {
 	externalCfg := &v1beta4.UpgradeConfiguration{}
@@ -119,7 +120,10 @@ func runDiff(fs *pflag.FlagSet, flags *diffFlags, args []string, fetchInitConfig
 	if err != nil {
 		return errors.Wrapf(err, "couldn't create a Kubernetes client from file %q", flags.kubeConfigPath)
 	}
-	initCfg, err := fetchInitConfigurationFromCluster(client, &output.TextPrinter{}, "upgrade/diff", false, true)
+	getNodeRegistration := true
+	getAPIEndpoint := staticpodutil.IsControlPlaneNode()
+	getComponentConfigs := false
+	initCfg, err := fetchInitConfigurationFromCluster(client, &output.TextPrinter{}, "upgrade/diff", getNodeRegistration, getAPIEndpoint, getComponentConfigs)
 	if err != nil {
 		return err
 	}

cmd/kubeadm/app/cmd/upgrade/diff_test.go

@@ -44,7 +44,7 @@ func createTestRunDiffFile(contents []byte) (string, error) {
 	return file.Name(), nil
 }
 
-func fakeFetchInitConfig(client clientset.Interface, printer output.Printer, logPrefix string, newControlPlane, skipComponentConfigs bool) (*kubeadmapi.InitConfiguration, error) {
+func fakeFetchInitConfig(client clientset.Interface, printer output.Printer, logPrefix string, getNodeRegistration, getAPIEndpoint, getComponentConfigs bool) (*kubeadmapi.InitConfiguration, error) {
 	return &kubeadmapi.InitConfiguration{
 		ClusterConfiguration: kubeadmapi.ClusterConfiguration{
 			KubernetesVersion: "v1.0.1",

cmd/kubeadm/app/cmd/upgrade/node.go

@@ -19,7 +19,6 @@ package upgrade
 import (
 	"fmt"
 	"io"
-	"os"
 
 	"github.com/spf13/cobra"
 	flag "github.com/spf13/pflag"
@@ -40,6 +39,7 @@ import (
 	configutil "k8s.io/kubernetes/cmd/kubeadm/app/util/config"
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/errors"
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/output"
+	staticpodutil "k8s.io/kubernetes/cmd/kubeadm/app/util/staticpod"
 )
 
 // nodeOptions defines all the options exposed via flags by kubeadm upgrade node.
@@ -165,13 +165,8 @@ func addUpgradeNodeFlags(flagSet *flag.FlagSet, nodeOptions *nodeOptions) {
 // This func takes care of validating nodeOptions passed to the command, and then it converts
 // options into the internal InitConfiguration type that is used as input all the phases in the kubeadm upgrade node workflow
 func newNodeData(cmd *cobra.Command, nodeOptions *nodeOptions, out io.Writer) (*nodeData, error) {
-	// Checks if a node is a control-plane node by looking up the kube-apiserver manifest file
-	isControlPlaneNode := true
-	filepath := constants.GetStaticPodFilepath(constants.KubeAPIServer, constants.GetStaticPodDirectory())
-	if _, err := os.Stat(filepath); os.IsNotExist(err) {
-		klog.V(1).Infof("assuming this is not a control plane node because %q is missing", filepath)
-		isControlPlaneNode = false
-	}
+	isControlPlaneNode := staticpodutil.IsControlPlaneNode()
+
 	if len(nodeOptions.kubeConfigPath) == 0 {
 		// Update the kubeconfig path depending on whether this is a control plane node or not.
 		nodeOptions.kubeConfigPath = constants.GetKubeletKubeConfigPath()
@@ -207,9 +202,10 @@ func newNodeData(cmd *cobra.Command, nodeOptions *nodeOptions, out io.Writer) (*
 	}
 
 	// Fetches the cluster configuration
-	// NB in case of control-plane node, we are reading all the info for the node; in case of NOT control-plane node
-	//    (worker node), we are not reading local API address and the CRI socket from the node object
-	initCfg, err := configutil.FetchInitConfigurationFromCluster(client, nil, "upgrade", !isControlPlaneNode, false)
+	getNodeRegistration := true
+	getAPIEndpoint := isControlPlaneNode
+	getComponentConfigs := true
+	initCfg, err := configutil.FetchInitConfigurationFromCluster(client, nil, "upgrade", getNodeRegistration, getAPIEndpoint, getComponentConfigs)
 	if err != nil {
 		return nil, errors.Wrap(err, "unable to fetch the kubeadm-config ConfigMap")
 	}

cmd/kubeadm/app/util/config/cluster.go

@@ -51,7 +51,7 @@ import (
 )
 
 // FetchInitConfigurationFromCluster fetches configuration from a ConfigMap in the cluster
-func FetchInitConfigurationFromCluster(client clientset.Interface, printer output.Printer, logPrefix string, newControlPlane, skipComponentConfigs bool) (*kubeadmapi.InitConfiguration, error) {
+func FetchInitConfigurationFromCluster(client clientset.Interface, printer output.Printer, logPrefix string, getNodeRegistration, getAPIEndpoint, getComponentConfigs bool) (*kubeadmapi.InitConfiguration, error) {
 	if printer == nil {
 		printer = &output.TextPrinter{}
 	}
@@ -60,7 +60,7 @@ func FetchInitConfigurationFromCluster(client clientset.Interface, printer outpu
 	_, _ = printer.Printf("[%s] Use 'kubeadm init phase upload-config kubeadm --config your-config-file' to re-upload it.\n", logPrefix)
 
 	// Fetch the actual config from cluster
-	cfg, err := getInitConfigurationFromCluster(constants.KubernetesDir, client, newControlPlane, skipComponentConfigs)
+	cfg, err := getInitConfigurationFromCluster(constants.KubernetesDir, client, getNodeRegistration, getAPIEndpoint, getComponentConfigs)
 	if err != nil {
 		return nil, err
 	}
@@ -75,7 +75,7 @@ func FetchInitConfigurationFromCluster(client clientset.Interface, printer outpu
 }
 
 // getInitConfigurationFromCluster is separate only for testing purposes, don't call it directly, use FetchInitConfigurationFromCluster instead
-func getInitConfigurationFromCluster(kubeconfigDir string, client clientset.Interface, newControlPlane, skipComponentConfigs bool) (*kubeadmapi.InitConfiguration, error) {
+func getInitConfigurationFromCluster(kubeconfigDir string, client clientset.Interface, getNodeRegistration, getAPIEndpoint, getComponentConfigs bool) (*kubeadmapi.InitConfiguration, error) {
 	// Also, the config map really should be KubeadmConfigConfigMap...
 	configMap, err := apiclient.GetConfigMapWithShortRetry(client, metav1.NamespaceSystem, constants.KubeadmConfigConfigMap)
 	if err != nil {
@@ -105,26 +105,28 @@ func getInitConfigurationFromCluster(kubeconfigDir string, client clientset.Inte
 		return nil, errors.Wrap(err, "failed to decode cluster configuration data")
 	}
 
-	if !skipComponentConfigs {
+	if getComponentConfigs {
 		// get the component configs from the corresponding config maps
 		if err := componentconfigs.FetchFromCluster(&initcfg.ClusterConfiguration, client); err != nil {
 			return nil, errors.Wrap(err, "failed to get component configs")
 		}
 	}
 
-	// if this isn't a new controlplane instance (e.g. in case of kubeadm upgrades)
-	// get nodes specific information as well
-	if !newControlPlane {
+	if getNodeRegistration {
 		// gets the nodeRegistration for the current from the node object
 		kubeconfigFile := filepath.Join(kubeconfigDir, constants.KubeletKubeConfigFileName)
 		if err := GetNodeRegistration(kubeconfigFile, client, &initcfg.NodeRegistration, &initcfg.ClusterConfiguration); err != nil {
 			return nil, errors.Wrap(err, "failed to get node registration")
 		}
-		// gets the APIEndpoint for the current node
-		if err := getAPIEndpoint(client, initcfg.NodeRegistration.Name, &initcfg.LocalAPIEndpoint); err != nil {
+	}
+
+	if getAPIEndpoint {
+		// gets the APIEndpoint for the current control plane node
+		if err := GetAPIEndpoint(client, initcfg.NodeRegistration.Name, &initcfg.LocalAPIEndpoint); err != nil {
 			return nil, errors.Wrap(err, "failed to getAPIEndpoint")
 		}
 	}
+
 	return initcfg, nil
 }
 
@@ -257,7 +259,8 @@ func getNodeNameFromSSR(client clientset.Interface) (string, error) {
 	return strings.TrimPrefix(user, constants.NodesUserPrefix), nil
 }
 
-func getAPIEndpoint(client clientset.Interface, nodeName string, apiEndpoint *kubeadmapi.APIEndpoint) error {
+// GetAPIEndpoint gets the API endpoint for a given node.
+func GetAPIEndpoint(client clientset.Interface, nodeName string, apiEndpoint *kubeadmapi.APIEndpoint) error {
 	return getAPIEndpointWithRetry(client, nodeName, apiEndpoint,
 		constants.KubernetesAPICallRetryInterval, kubeadmapi.GetActiveTimeouts().KubernetesAPICall.Duration)
 }

cmd/kubeadm/app/util/config/cluster_test.go

@@ -491,13 +491,14 @@ func TestGetInitConfigurationFromCluster(t *testing.T) {
 	defer os.RemoveAll(tmpdir)
 
 	var tests = []struct {
-		name            string
-		fileContents    []byte
-		node            *v1.Node
-		staticPods      []testresources.FakeStaticPod
-		configMaps      []testresources.FakeConfigMap
-		newControlPlane bool
-		expectedError   bool
+		name                string
+		fileContents        []byte
+		node                *v1.Node
+		staticPods          []testresources.FakeStaticPod
+		configMaps          []testresources.FakeConfigMap
+		getNodeRegistration bool
+		getAPIEndpoint      bool
+		expectedError       bool
 	}{
 		{
 			name:          "invalid - No kubeadm-config ConfigMap",
@@ -556,6 +557,8 @@ func TestGetInitConfigurationFromCluster(t *testing.T) {
 					Taints: []v1.Taint{kubeadmconstants.ControlPlaneTaint},
 				},
 			},
+			getNodeRegistration: true,
+			getAPIEndpoint:      true,
 		},
 		{
 			name: "valid v1beta3 - new control plane == true", // InitConfiguration composed with data from different places, without node specific information
@@ -588,7 +591,8 @@ func TestGetInitConfigurationFromCluster(t *testing.T) {
 					},
 				},
 			},
-			newControlPlane: true,
+			getNodeRegistration: false,
+			getAPIEndpoint:      false,
 		},
 	}
 
@@ -629,7 +633,8 @@ func TestGetInitConfigurationFromCluster(t *testing.T) {
 				}
 			}
 
-			cfg, err := getInitConfigurationFromCluster(tmpdir, client, rt.newControlPlane, false)
+			getComponentConfigs := true
+			cfg, err := getInitConfigurationFromCluster(tmpdir, client, rt.getNodeRegistration, rt.getAPIEndpoint, getComponentConfigs)
 			if rt.expectedError != (err != nil) {
 				t.Errorf("unexpected return err from getInitConfigurationFromCluster: %v", err)
 				return
@@ -649,13 +654,13 @@ func TestGetInitConfigurationFromCluster(t *testing.T) {
 			if cfg.NodeRegistration.ImagePullPolicy != kubeadmapiv1.DefaultImagePullPolicy {
 				t.Errorf("invalid cfg.NodeRegistration.ImagePullPolicy %v", cfg.NodeRegistration.ImagePullPolicy)
 			}
-			if !rt.newControlPlane && (cfg.LocalAPIEndpoint.AdvertiseAddress != "1.2.3.4" || cfg.LocalAPIEndpoint.BindPort != 1234) {
+			if rt.getNodeRegistration && rt.getAPIEndpoint && (cfg.LocalAPIEndpoint.AdvertiseAddress != "1.2.3.4" || cfg.LocalAPIEndpoint.BindPort != 1234) {
 				t.Errorf("invalid cfg.LocalAPIEndpoint: %v", cfg.LocalAPIEndpoint)
 			}
-			if !rt.newControlPlane && (cfg.NodeRegistration.Name != nodeName || cfg.NodeRegistration.CRISocket != "myCRIsocket" || len(cfg.NodeRegistration.Taints) != 1) {
+			if rt.getNodeRegistration && (cfg.NodeRegistration.Name != nodeName || cfg.NodeRegistration.CRISocket != "myCRIsocket" || len(cfg.NodeRegistration.Taints) != 1) {
 				t.Errorf("invalid cfg.NodeRegistration: %v", cfg.NodeRegistration)
 			}
-			if rt.newControlPlane && len(cfg.NodeRegistration.CRISocket) > 0 {
+			if !rt.getNodeRegistration && len(cfg.NodeRegistration.CRISocket) > 0 {
 				t.Errorf("invalid cfg.NodeRegistration.CRISocket: expected empty CRISocket, but got %v", cfg.NodeRegistration.CRISocket)
 			}
 			if _, ok := cfg.ComponentConfigs[componentconfigs.KubeletGroup]; !ok {

cmd/kubeadm/app/util/staticpod/utils.go

@@ -419,3 +419,18 @@ func DeepHashObject(hasher hash.Hash, objectToWrite interface{}) {
 	hasher.Reset()
 	fmt.Fprintf(hasher, "%v", dump.ForHash(objectToWrite))
 }
+
+// IsControlPlaneNode returns true if the kube-apiserver static pod manifest is present
+// on the host.
+func IsControlPlaneNode() bool {
+	isControlPlaneNode := true
+
+	filepath := kubeadmconstants.GetStaticPodFilepath(kubeadmconstants.KubeAPIServer,
+		kubeadmconstants.GetStaticPodDirectory())
+
+	if _, err := os.Stat(filepath); os.IsNotExist(err) {
+		isControlPlaneNode = false
+	}
+
+	return isControlPlaneNode
+}