kubeadm: config migrate handles more valid configs

cmd/kubeadm/app/cmd/config.go

@@ -329,10 +329,7 @@ func NewCmdConfigMigrate(out io.Writer) *cobra.Command {
 				kubeadmutil.CheckErr(errors.New("The --old-config flag is mandatory"))
 			}
 
-			internalcfg, err := configutil.AnyConfigFileAndDefaultsToInternal(oldCfgPath)
-			kubeadmutil.CheckErr(err)
-
-			outputBytes, err := configutil.MarshalKubeadmConfigObject(internalcfg)
+			outputBytes, err := configutil.MigrateOldConfigFromFile(oldCfgPath)
 			kubeadmutil.CheckErr(err)
 
 			if newCfgPath == "" {

cmd/kubeadm/app/util/config/BUILD

@@ -65,6 +65,7 @@ go_test(
         "//staging/src/k8s.io/client-go/kubernetes:go_default_library",
         "//staging/src/k8s.io/client-go/kubernetes/fake:go_default_library",
         "//vendor/github.com/pmezard/go-difflib/difflib:go_default_library",
+        "//vendor/github.com/renstrom/dedent:go_default_library",
     ],
 )
 

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

@@ -17,6 +17,7 @@ limitations under the License.
 package config
 
 import (
+	"bytes"
 	"io/ioutil"
 	"net"
 	"reflect"
@@ -35,28 +36,6 @@ import (
 	kubeadmutil "k8s.io/kubernetes/cmd/kubeadm/app/util"
 )
 
-// AnyConfigFileAndDefaultsToInternal reads either a InitConfiguration or JoinConfiguration and unmarshals it
-func AnyConfigFileAndDefaultsToInternal(cfgPath string) (runtime.Object, error) {
-	b, err := ioutil.ReadFile(cfgPath)
-	if err != nil {
-		return nil, err
-	}
-
-	gvks, err := kubeadmutil.GroupVersionKindsFromBytes(b)
-	if err != nil {
-		return nil, err
-	}
-
-	// First, check if the gvk list has InitConfiguration and in that case try to unmarshal it
-	if kubeadmutil.GroupVersionKindsHasInitConfiguration(gvks...) {
-		return ConfigFileAndDefaultsToInternalConfig(cfgPath, &kubeadmapiv1beta1.InitConfiguration{})
-	}
-	if kubeadmutil.GroupVersionKindsHasJoinConfiguration(gvks...) {
-		return JoinConfigFileAndDefaultsToInternalConfig(cfgPath, &kubeadmapiv1beta1.JoinConfiguration{})
-	}
-	return nil, errors.Errorf("didn't recognize types with GroupVersionKind: %v", gvks)
-}
-
 // MarshalKubeadmConfigObject marshals an Object registered in the kubeadm scheme. If the object is a InitConfiguration or ClusterConfiguration, some extra logic is run
 func MarshalKubeadmConfigObject(obj runtime.Object) ([]byte, error) {
 	switch internalcfg := obj.(type) {
@@ -181,3 +160,46 @@ func ChooseAPIServerBindAddress(bindAddress net.IP) (net.IP, error) {
 	}
 	return ip, nil
 }
+
+// MigrateOldConfigFromFile migrates an old configuration from a file into a new one (returned as a byte slice). Only kubeadm kinds are migrated. Others are silently ignored.
+func MigrateOldConfigFromFile(cfgPath string) ([]byte, error) {
+	newConfig := [][]byte{}
+
+	cfgBytes, err := ioutil.ReadFile(cfgPath)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	gvks, err := kubeadmutil.GroupVersionKindsFromBytes(cfgBytes)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	// Migrate InitConfiguration and ClusterConfiguration if there are any in the config
+	if kubeadmutil.GroupVersionKindsHasInitConfiguration(gvks...) || kubeadmutil.GroupVersionKindsHasClusterConfiguration(gvks...) {
+		o, err := ConfigFileAndDefaultsToInternalConfig(cfgPath, &kubeadmapiv1beta1.InitConfiguration{})
+		if err != nil {
+			return []byte{}, err
+		}
+		b, err := MarshalKubeadmConfigObject(o)
+		if err != nil {
+			return []byte{}, err
+		}
+		newConfig = append(newConfig, b)
+	}
+
+	// Migrate JoinConfiguration if there is any
+	if kubeadmutil.GroupVersionKindsHasJoinConfiguration(gvks...) {
+		o, err := JoinConfigFileAndDefaultsToInternalConfig(cfgPath, &kubeadmapiv1beta1.JoinConfiguration{})
+		if err != nil {
+			return []byte{}, err
+		}
+		b, err := MarshalKubeadmConfigObject(o)
+		if err != nil {
+			return []byte{}, err
+		}
+		newConfig = append(newConfig, b)
+	}
+
+	return bytes.Join(newConfig, []byte(constants.YAMLDocumentSeparator)), nil
+}

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

@@ -18,10 +18,15 @@ package config
 
 import (
 	"bytes"
+	"io/ioutil"
+	"os"
 	"testing"
 
+	"github.com/renstrom/dedent"
+
 	kubeadmapiv1beta1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta1"
 	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
+	kubeadmutil "k8s.io/kubernetes/cmd/kubeadm/app/util"
 )
 
 var files = map[string][]byte{
@@ -298,3 +303,212 @@ func TestVerifyAPIServerBindAddress(t *testing.T) {
 		})
 	}
 }
+
+func TestMigrateOldConfigFromFile(t *testing.T) {
+	tests := []struct {
+		desc          string
+		oldCfg        string
+		expectedKinds []string
+		expectErr     bool
+	}{
+		{
+			desc:      "empty file produces empty result",
+			oldCfg:    "",
+			expectErr: false,
+		},
+		{
+			desc: "bad config produces error",
+			oldCfg: dedent.Dedent(`
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			`),
+			expectErr: true,
+		},
+		{
+			desc: "InitConfiguration only gets migrated",
+			oldCfg: dedent.Dedent(`
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: InitConfiguration
+			`),
+			expectedKinds: []string{
+				constants.InitConfigurationKind,
+				constants.ClusterConfigurationKind,
+			},
+			expectErr: false,
+		},
+		{
+			desc: "ClusterConfiguration only gets migrated",
+			oldCfg: dedent.Dedent(`
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: ClusterConfiguration
+			`),
+			expectedKinds: []string{
+				constants.InitConfigurationKind,
+				constants.ClusterConfigurationKind,
+			},
+			expectErr: false,
+		},
+		{
+			desc: "JoinConfiguration only gets migrated",
+			oldCfg: dedent.Dedent(`
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: JoinConfiguration
+			token: abcdef.0123456789abcdef
+			discoveryTokenAPIServers:
+			- kube-apiserver:6443
+			discoveryTokenUnsafeSkipCAVerification: true
+			`),
+			expectedKinds: []string{
+				constants.JoinConfigurationKind,
+			},
+			expectErr: false,
+		},
+		{
+			desc: "Init + Cluster Configurations are migrated",
+			oldCfg: dedent.Dedent(`
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: InitConfiguration
+			---
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: ClusterConfiguration
+			`),
+			expectedKinds: []string{
+				constants.InitConfigurationKind,
+				constants.ClusterConfigurationKind,
+			},
+			expectErr: false,
+		},
+		{
+			desc: "Init + Join Configurations are migrated",
+			oldCfg: dedent.Dedent(`
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: InitConfiguration
+			---
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: JoinConfiguration
+			token: abcdef.0123456789abcdef
+			discoveryTokenAPIServers:
+			- kube-apiserver:6443
+			discoveryTokenUnsafeSkipCAVerification: true
+			`),
+			expectedKinds: []string{
+				constants.InitConfigurationKind,
+				constants.ClusterConfigurationKind,
+				constants.JoinConfigurationKind,
+			},
+			expectErr: false,
+		},
+		{
+			desc: "Cluster + Join Configurations are migrated",
+			oldCfg: dedent.Dedent(`
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: ClusterConfiguration
+			---
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: JoinConfiguration
+			token: abcdef.0123456789abcdef
+			discoveryTokenAPIServers:
+			- kube-apiserver:6443
+			discoveryTokenUnsafeSkipCAVerification: true
+			`),
+			expectedKinds: []string{
+				constants.InitConfigurationKind,
+				constants.ClusterConfigurationKind,
+				constants.JoinConfigurationKind,
+			},
+			expectErr: false,
+		},
+		{
+			desc: "Init + Cluster + Join Configurations are migrated",
+			oldCfg: dedent.Dedent(`
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: InitConfiguration
+			---
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: ClusterConfiguration
+			---
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: JoinConfiguration
+			token: abcdef.0123456789abcdef
+			discoveryTokenAPIServers:
+			- kube-apiserver:6443
+			discoveryTokenUnsafeSkipCAVerification: true
+			`),
+			expectedKinds: []string{
+				constants.InitConfigurationKind,
+				constants.ClusterConfigurationKind,
+				constants.JoinConfigurationKind,
+			},
+			expectErr: false,
+		},
+		{
+			desc: "component configs are not migrated",
+			oldCfg: dedent.Dedent(`
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: InitConfiguration
+			---
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: ClusterConfiguration
+			---
+			apiVersion: kubeadm.k8s.io/v1alpha3
+			kind: JoinConfiguration
+			token: abcdef.0123456789abcdef
+			discoveryTokenAPIServers:
+			- kube-apiserver:6443
+			discoveryTokenUnsafeSkipCAVerification: true
+			---
+			apiVersion: kubeproxy.config.k8s.io/v1alpha1
+			kind: KubeProxyConfiguration
+			---
+			apiVersion: kubelet.config.k8s.io/v1beta1
+			kind: KubeletConfiguration
+			`),
+			expectedKinds: []string{
+				constants.InitConfigurationKind,
+				constants.ClusterConfigurationKind,
+				constants.JoinConfigurationKind,
+			},
+			expectErr: false,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.desc, func(t *testing.T) {
+			file, err := ioutil.TempFile("", "")
+			if err != nil {
+				t.Fatalf("could not create temporary test file: %v", err)
+			}
+			fileName := file.Name()
+			defer os.Remove(fileName)
+
+			_, err = file.WriteString(test.oldCfg)
+			file.Close()
+			if err != nil {
+				t.Fatalf("could not write contents of old config: %v", err)
+			}
+
+			b, err := MigrateOldConfigFromFile(fileName)
+			if test.expectErr {
+				if err == nil {
+					t.Fatalf("unexpected success:\n%s", b)
+				}
+			} else {
+				if err != nil {
+					t.Fatalf("unexpected failure: %v", err)
+				}
+				gvks, err := kubeadmutil.GroupVersionKindsFromBytes(b)
+				if err != nil {
+					t.Fatalf("unexpected error returned by GroupVersionKindsFromBytes: %v", err)
+				}
+				if len(gvks) != len(test.expectedKinds) {
+					t.Fatalf("length mismatch between resulting gvks and expected kinds:\n\tlen(gvks)=%d\n\tlen(expectedKinds)=%d",
+						len(gvks), len(test.expectedKinds))
+				}
+				for _, expectedKind := range test.expectedKinds {
+					if !kubeadmutil.GroupVersionKindsHasKind(gvks, expectedKind) {
+						t.Fatalf("migration failed to produce config kind: %s", expectedKind)
+					}
+				}
+			}
+		})
+	}
+}