kubeadm - fix external etcd upgrades

- Update upgrade plan output when configured for external etcd
  - Move etcd to a separate section and show available upgrades

cmd/kubeadm/app/cmd/upgrade/plan.go

@@ -124,13 +124,13 @@ func RunPlan(flags *planFlags) error {
 	}
 
 	// Tell the user which upgrades are available
-	printAvailableUpgrades(availUpgrades, os.Stdout, upgradeVars.cfg.FeatureGates)
+	printAvailableUpgrades(availUpgrades, os.Stdout, upgradeVars.cfg.FeatureGates, isExternalEtcd)
 	return nil
 }
 
 // printAvailableUpgrades prints a UX-friendly overview of what versions are available to upgrade to
 // TODO look into columnize or some other formatter when time permits instead of using the tabwriter
-func printAvailableUpgrades(upgrades []upgrade.Upgrade, w io.Writer, featureGates map[string]bool) {
+func printAvailableUpgrades(upgrades []upgrade.Upgrade, w io.Writer, featureGates map[string]bool, isExternalEtcd bool) {
 
 	// Return quickly if no upgrades can be made
 	if len(upgrades) == 0 {
@@ -143,6 +143,16 @@ func printAvailableUpgrades(upgrades []upgrade.Upgrade, w io.Writer, featureGate
 	// Loop through the upgrade possibilities and output text to the command line
 	for _, upgrade := range upgrades {
 
+		if isExternalEtcd && upgrade.CanUpgradeEtcd() {
+			fmt.Fprintln(w, "External components that should be upgraded manually before you upgrade the control plane with 'kubeadm upgrade apply':")
+			fmt.Fprintln(tabw, "COMPONENT\tCURRENT\tAVAILABLE")
+			fmt.Fprintf(tabw, "Etcd\t%s\t%s\n", upgrade.Before.EtcdVersion, upgrade.After.EtcdVersion)
+
+			// We should flush the writer here at this stage; as the columns will now be of the right size, adjusted to the above content
+			tabw.Flush()
+			fmt.Fprintln(w, "")
+		}
+
 		if upgrade.CanUpgradeKubelets() {
 			fmt.Fprintln(w, "Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':")
 			fmt.Fprintln(tabw, "COMPONENT\tCURRENT\tAVAILABLE")
@@ -177,7 +187,9 @@ func printAvailableUpgrades(upgrades []upgrade.Upgrade, w io.Writer, featureGate
 		} else {
 			fmt.Fprintf(tabw, "Kube DNS\t%s\t%s\n", upgrade.Before.DNSVersion, upgrade.After.DNSVersion)
 		}
-		fmt.Fprintf(tabw, "Etcd\t%s\t%s\n", upgrade.Before.EtcdVersion, upgrade.After.EtcdVersion)
+		if !isExternalEtcd {
+			fmt.Fprintf(tabw, "Etcd\t%s\t%s\n", upgrade.Before.EtcdVersion, upgrade.After.EtcdVersion)
+		}
 
 		// The tabwriter should be flushed at this stage as we have now put in all the required content for this time. This is required for the tabs' size to be correct.
 		tabw.Flush()

cmd/kubeadm/app/cmd/upgrade/plan_test.go

@@ -62,16 +62,27 @@ func TestSortedSliceFromStringIntMap(t *testing.T) {
 func TestPrintAvailableUpgrades(t *testing.T) {
 	featureGates := make(map[string]bool)
 	var tests = []struct {
+		name          string
 		upgrades      []upgrade.Upgrade
 		buf           *bytes.Buffer
 		expectedBytes []byte
+		externalEtcd  bool
 	}{
 		{
+			name:     "Up to date",
 			upgrades: []upgrade.Upgrade{},
 			expectedBytes: []byte(`Awesome, you're up-to-date! Enjoy!
 `),
 		},
 		{
+			name:         "Up to date external etcd",
+			externalEtcd: true,
+			upgrades:     []upgrade.Upgrade{},
+			expectedBytes: []byte(`Awesome, you're up-to-date! Enjoy!
+`),
+		},
+		{
+			name: "Patch version available",
 			upgrades: []upgrade.Upgrade{
 				{
 					Description: "version in the v1.8 series",
@@ -117,6 +128,7 @@ _____________________________________________________________________
 `),
 		},
 		{
+			name: "minor version available",
 			upgrades: []upgrade.Upgrade{
 				{
 					Description: "stable version",
@@ -160,6 +172,7 @@ _____________________________________________________________________
 `),
 		},
 		{
+			name: "patch and minor version available",
 			upgrades: []upgrade.Upgrade{
 				{
 					Description: "version in the v1.8 series",
@@ -243,6 +256,7 @@ _____________________________________________________________________
 `),
 		},
 		{
+			name: "experimental version available",
 			upgrades: []upgrade.Upgrade{
 				{
 					Description: "experimental version",
@@ -288,6 +302,7 @@ _____________________________________________________________________
 `),
 		},
 		{
+			name: "release candidate available",
 			upgrades: []upgrade.Upgrade{
 				{
 					Description: "release candidate version",
@@ -333,6 +348,7 @@ _____________________________________________________________________
 `),
 		},
 		{
+			name: "multiple kubelet versions",
 			upgrades: []upgrade.Upgrade{
 				{
 					Description: "version in the v1.9 series",
@@ -377,19 +393,71 @@ Note: Before you can perform this upgrade, you have to update kubeadm to v1.9.3.
 
 _____________________________________________________________________
 
+`),
+		},
+		{
+			name: "external etcd upgrade available",
+			upgrades: []upgrade.Upgrade{
+				{
+					Description: "version in the v1.9 series",
+					Before: upgrade.ClusterState{
+						KubeVersion: "v1.9.2",
+						KubeletVersions: map[string]uint16{
+							"v1.9.2": 1,
+						},
+						KubeadmVersion: "v1.9.2",
+						DNSVersion:     "1.14.5",
+						EtcdVersion:    "3.0.17",
+					},
+					After: upgrade.ClusterState{
+						KubeVersion:    "v1.9.3",
+						KubeadmVersion: "v1.9.3",
+						DNSVersion:     "1.14.8",
+						EtcdVersion:    "3.1.12",
+					},
+				},
+			},
+			externalEtcd: true,
+			expectedBytes: []byte(`External components that should be upgraded manually before you upgrade the control plane with 'kubeadm upgrade apply':
+COMPONENT   CURRENT   AVAILABLE
+Etcd        3.0.17    3.1.12
+
+Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':
+COMPONENT   CURRENT      AVAILABLE
+Kubelet     1 x v1.9.2   v1.9.3
+
+Upgrade to the latest version in the v1.9 series:
+
+COMPONENT            CURRENT   AVAILABLE
+API Server           v1.9.2    v1.9.3
+Controller Manager   v1.9.2    v1.9.3
+Scheduler            v1.9.2    v1.9.3
+Kube Proxy           v1.9.2    v1.9.3
+Kube DNS             1.14.5    1.14.8
+
+You can now apply the upgrade by executing the following command:
+
+	kubeadm upgrade apply v1.9.3
+
+Note: Before you can perform this upgrade, you have to update kubeadm to v1.9.3.
+
+_____________________________________________________________________
+
 `),
 		},
 	}
 	for _, rt := range tests {
-		rt.buf = bytes.NewBufferString("")
+		t.Run(rt.name, func(t *testing.T) {
-		printAvailableUpgrades(rt.upgrades, rt.buf, featureGates)
+			rt.buf = bytes.NewBufferString("")
-		actualBytes := rt.buf.Bytes()
+			printAvailableUpgrades(rt.upgrades, rt.buf, featureGates, rt.externalEtcd)
-		if !bytes.Equal(actualBytes, rt.expectedBytes) {
+			actualBytes := rt.buf.Bytes()
-			t.Errorf(
+			if !bytes.Equal(actualBytes, rt.expectedBytes) {
-				"failed PrintAvailableUpgrades:\n\texpected: %q\n\t  actual: %q",
+				t.Errorf(
-				string(rt.expectedBytes),
+					"failed PrintAvailableUpgrades:\n\texpected: %q\n\t  actual: %q",
-				string(actualBytes),
+					string(rt.expectedBytes),
-			)
+					string(actualBytes),
-		}
+				)
+			}
+		})
 	}
 }

cmd/kubeadm/app/phases/upgrade/compute.go

@@ -50,6 +50,11 @@ func (u *Upgrade) CanUpgradeKubelets() bool {
 	return !sameVersionFound
 }
 
+// CanUpgradeEtcd returns whether an upgrade of etcd is possible
+func (u *Upgrade) CanUpgradeEtcd() bool {
+	return u.Before.EtcdVersion != u.After.EtcdVersion
+}
+
 // ActiveDNSAddon returns the version of CoreDNS or kube-dns
 func ActiveDNSAddon(featureGates map[string]bool) string {
 	if features.Enabled(featureGates, features.CoreDNS) {
@@ -83,13 +88,13 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 	// Get the cluster version
 	clusterVersionStr, clusterVersion, err := versionGetterImpl.ClusterVersion()
 	if err != nil {
-		return nil, err
+		return upgrades, err
 	}
 
 	// Get current kubeadm CLI version
 	kubeadmVersionStr, kubeadmVersion, err := versionGetterImpl.KubeadmVersion()
 	if err != nil {
-		return nil, err
+		return upgrades, err
 	}
 
 	// Get and output the current latest stable version
@@ -103,13 +108,13 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 	// Get the kubelet versions in the cluster
 	kubeletVersions, err := versionGetterImpl.KubeletVersions()
 	if err != nil {
-		return nil, err
+		return upgrades, err
 	}
 
 	// Get current etcd version
-	etcdStatus, err := etcdClient.GetStatus()
+	etcdVersion, err := etcdClient.GetVersion()
 	if err != nil {
-		return nil, err
+		return upgrades, err
 	}
 
 	// Construct a descriptor for the current state of the world
@@ -118,7 +123,7 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 		DNSVersion:      dns.GetDNSVersion(clusterVersion, ActiveDNSAddon(featureGates)),
 		KubeadmVersion:  kubeadmVersionStr,
 		KubeletVersions: kubeletVersions,
-		EtcdVersion:     etcdStatus.Version,
+		EtcdVersion:     etcdVersion,
 	}
 
 	// Do a "dumb guess" that a new minor upgrade is available just because the latest stable version is higher than the cluster version
@@ -201,7 +206,7 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 		// Get and output the current latest unstable version
 		latestVersionStr, latestVersion, err := versionGetterImpl.VersionFromCILabel("latest", "experimental version")
 		if err != nil {
-			return nil, err
+			return upgrades, err
 		}
 
 		minorUnstable := latestVersion.Components()[1]
@@ -209,7 +214,7 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 		previousBranch := fmt.Sprintf("latest-1.%d", minorUnstable-1)
 		previousBranchLatestVersionStr, previousBranchLatestVersion, err := versionGetterImpl.VersionFromCILabel(previousBranch, "")
 		if err != nil {
-			return nil, err
+			return upgrades, err
 		}
 
 		// If that previous latest version is an RC, RCs are allowed and the cluster version is lower than the RC version, show the upgrade

cmd/kubeadm/app/phases/upgrade/compute_test.go

@@ -64,71 +64,44 @@ func (f *fakeVersionGetter) KubeletVersions() (map[string]uint16, error) {
 	}, nil
 }
 
-type fakeEtcdClient struct{ TLS bool }
+type fakeEtcdClient struct {
+	TLS                bool
+	mismatchedVersions bool
+}
 
 func (f fakeEtcdClient) HasTLS() bool { return f.TLS }
 
-func (f fakeEtcdClient) GetStatus() (*clientv3.StatusResponse, error) {
+func (f fakeEtcdClient) ClusterAvailable() (bool, error) { return true, nil }
-	//	clusterStatus, err := f.GetClusterStatus()
+
-	//	return clusterStatus[0], err
+func (f fakeEtcdClient) WaitForClusterAvailable(delay time.Duration, retries int, retryInterval time.Duration) (bool, error) {
-	return &clientv3.StatusResponse{
+	return true, nil
-		Version: "3.1.12",
+}
+
+func (f fakeEtcdClient) GetClusterStatus() (map[string]*clientv3.StatusResponse, error) {
+	return make(map[string]*clientv3.StatusResponse), nil
+}
+
+func (f fakeEtcdClient) GetVersion() (string, error) {
+	versions, _ := f.GetClusterVersions()
+	if f.mismatchedVersions {
+		return "", fmt.Errorf("etcd cluster contains endpoints with mismatched versions: %v", versions)
+	}
+	return "3.1.12", nil
+}
+
+func (f fakeEtcdClient) GetClusterVersions() (map[string]string, error) {
+	if f.mismatchedVersions {
+		return map[string]string{
+			"foo": "3.1.12",
+			"bar": "3.2.0",
+		}, nil
+	}
+	return map[string]string{
+		"foo": "3.1.12",
+		"bar": "3.1.12",
 	}, nil
 }
 
-func (f fakeEtcdClient) GetClusterStatus() ([]*clientv3.StatusResponse, error) {
-	var responses []*clientv3.StatusResponse
-	responses = append(responses, &clientv3.StatusResponse{
-		Version: "3.1.12",
-	})
-	return responses, nil
-}
-
-func (f fakeEtcdClient) WaitForStatus(delay time.Duration, retries int, retryInterval time.Duration) (*clientv3.StatusResponse, error) {
-	return f.GetStatus()
-}
-
-type mismatchEtcdClient struct{}
-
-func (f mismatchEtcdClient) HasTLS() bool { return true }
-
-func (f mismatchEtcdClient) GetStatus() (*clientv3.StatusResponse, error) {
-	clusterStatus, err := f.GetClusterStatus()
-	return clusterStatus[0], err
-}
-
-func (f mismatchEtcdClient) GetClusterStatus() ([]*clientv3.StatusResponse, error) {
-	return []*clientv3.StatusResponse{
-		&clientv3.StatusResponse{
-			Version: "3.1.12",
-		},
-		&clientv3.StatusResponse{
-			Version: "3.2.0",
-		},
-	}, nil
-}
-
-func (f mismatchEtcdClient) WaitForStatus(delay time.Duration, retries int, retryInterval time.Duration) (*clientv3.StatusResponse, error) {
-	return f.GetStatus()
-}
-
-type degradedEtcdClient struct{}
-
-func (f degradedEtcdClient) HasTLS() bool { return true }
-
-func (f degradedEtcdClient) GetStatus() (*clientv3.StatusResponse, error) {
-	return nil, fmt.Errorf("Degraded etcd cluster")
-}
-
-func (f degradedEtcdClient) GetClusterStatus() ([]*clientv3.StatusResponse, error) {
-	var res []*clientv3.StatusResponse
-	return res, fmt.Errorf("Degraded etcd cluster")
-}
-
-func (f degradedEtcdClient) WaitForStatus(delay time.Duration, retries int, retryInterval time.Duration) (*clientv3.StatusResponse, error) {
-	return f.GetStatus()
-}
-
 func TestGetAvailableUpgrades(t *testing.T) {
 	featureGates := make(map[string]bool)
 	etcdClient := fakeEtcdClient{}
@@ -569,22 +542,7 @@ func TestGetAvailableUpgrades(t *testing.T) {
 			},
 			allowRCs:          false,
 			allowExperimental: false,
-			etcdClient:        mismatchEtcdClient{},
+			etcdClient:        fakeEtcdClient{mismatchedVersions: true},
-			expectedUpgrades:  []Upgrade{},
-			errExpected:       true,
-		},
-		{
-			name: "Upgrades with external etcd with a degraded status should not be allowed.",
-			vg: &fakeVersionGetter{
-				clusterVersion:     "v1.9.3",
-				kubeletVersion:     "v1.9.3",
-				kubeadmVersion:     "v1.9.3",
-				stablePatchVersion: "v1.9.3",
-				stableVersion:      "v1.9.3",
-			},
-			allowRCs:          false,
-			allowExperimental: false,
-			etcdClient:        degradedEtcdClient{},
 			expectedUpgrades:  []Upgrade{},
 			errExpected:       true,
 		},
@@ -624,12 +582,16 @@ func TestGetAvailableUpgrades(t *testing.T) {
 	for _, rt := range tests {
 		t.Run(rt.name, func(t *testing.T) {
 			actualUpgrades, actualErr := GetAvailableUpgrades(rt.vg, rt.allowExperimental, rt.allowRCs, rt.etcdClient, featureGates)
+			fmt.Printf("actualErr: %v\n", actualErr)
+			fmt.Printf("actualErr != nil: %v\n", actualErr != nil)
+			fmt.Printf("errExpected: %v\n", rt.errExpected)
+			if (actualErr != nil) != rt.errExpected {
+				fmt.Printf("Hello error")
+				t.Errorf("failed TestGetAvailableUpgrades\n\texpected error: %t\n\tgot error: %t", rt.errExpected, (actualErr != nil))
+			}
 			if !reflect.DeepEqual(actualUpgrades, rt.expectedUpgrades) {
 				t.Errorf("failed TestGetAvailableUpgrades\n\texpected upgrades: %v\n\tgot: %v", rt.expectedUpgrades, actualUpgrades)
 			}
-			if (actualErr != nil) != rt.errExpected {
-				t.Errorf("failed TestGetAvailableUpgrades\n\texpected error: %t\n\tgot error: %t", rt.errExpected, (actualErr != nil))
-			}
 		})
 	}
 }

cmd/kubeadm/app/phases/upgrade/staticpods.go

@@ -231,7 +231,7 @@ func performEtcdStaticPodUpgrade(waiter apiclient.Waiter, pathMgr StaticPodPathM
 	}
 
 	// Checking health state of etcd before proceeding with the upgrade
-	etcdStatus, err := oldEtcdClient.GetStatus()
+	_, err := oldEtcdClient.GetClusterStatus()
 	if err != nil {
 		return true, fmt.Errorf("etcd cluster is not healthy: %v", err)
 	}
@@ -248,9 +248,13 @@ func performEtcdStaticPodUpgrade(waiter apiclient.Waiter, pathMgr StaticPodPathM
 	if err != nil {
 		return true, fmt.Errorf("failed to retrieve an etcd version for the target kubernetes version: %v", err)
 	}
-	currentEtcdVersion, err := version.ParseSemantic(etcdStatus.Version)
+	currentEtcdVersionStr, err := oldEtcdClient.GetVersion()
 	if err != nil {
-		return true, fmt.Errorf("failed to parse the current etcd version(%s): %v", etcdStatus.Version, err)
+		return true, fmt.Errorf("failed to retrieve the current etcd version: %v", err)
+	}
+	currentEtcdVersion, err := version.ParseSemantic(currentEtcdVersionStr)
+	if err != nil {
+		return true, fmt.Errorf("failed to parse the current etcd version(%s): %v", currentEtcdVersionStr, err)
 	}
 
 	// Comparing current etcd version with desired to catch the same version or downgrade condition and fail on them.
@@ -292,7 +296,7 @@ func performEtcdStaticPodUpgrade(waiter apiclient.Waiter, pathMgr StaticPodPathM
 		// Since upgrade component failed, the old etcd manifest has either been restored or was never touched
 		// Now we need to check the health of etcd cluster if it is up with old manifest
 		fmt.Println("[upgrade/etcd] Waiting for previous etcd to become available")
-		if _, err := oldEtcdClient.WaitForStatus(noDelay, retries, retryInterval); err != nil {
+		if _, err := oldEtcdClient.WaitForClusterAvailable(noDelay, retries, retryInterval); err != nil {
 			fmt.Printf("[upgrade/etcd] Failed to healthcheck previous etcd: %v\n", err)
 
 			// At this point we know that etcd cluster is dead and it is safe to copy backup datastore and to rollback old etcd manifest
@@ -305,7 +309,7 @@ func performEtcdStaticPodUpgrade(waiter apiclient.Waiter, pathMgr StaticPodPathM
 
 			// Now that we've rolled back the data, let's check if the cluster comes up
 			fmt.Println("[upgrade/etcd] Waiting for previous etcd to become available")
-			if _, err := oldEtcdClient.WaitForStatus(noDelay, retries, retryInterval); err != nil {
+			if _, err := oldEtcdClient.WaitForClusterAvailable(noDelay, retries, retryInterval); err != nil {
 				fmt.Printf("[upgrade/etcd] Failed to healthcheck previous etcd: %v\n", err)
 				// Nothing else left to try to recover etcd cluster
 				return true, fmt.Errorf("fatal error rolling back local etcd cluster manifest: %v, the backup of etcd database is stored here:(%s)", err, backupEtcdDir)
@@ -334,7 +338,7 @@ func performEtcdStaticPodUpgrade(waiter apiclient.Waiter, pathMgr StaticPodPathM
 
 	// Checking health state of etcd after the upgrade
 	fmt.Println("[upgrade/etcd] Waiting for etcd to become available")
-	if _, err = newEtcdClient.WaitForStatus(podRestartDelay, retries, retryInterval); err != nil {
+	if _, err = newEtcdClient.WaitForClusterAvailable(podRestartDelay, retries, retryInterval); err != nil {
 		fmt.Printf("[upgrade/etcd] Failed to healthcheck etcd: %v\n", err)
 		// Despite the fact that upgradeComponent was successful, there is something wrong with the etcd cluster
 		// First step is to restore back up of datastore
@@ -352,7 +356,7 @@ func performEtcdStaticPodUpgrade(waiter apiclient.Waiter, pathMgr StaticPodPathM
 
 		// Assuming rollback of the old etcd manifest was successful, check the status of etcd cluster again
 		fmt.Println("[upgrade/etcd] Waiting for previous etcd to become available")
-		if _, err := oldEtcdClient.WaitForStatus(noDelay, retries, retryInterval); err != nil {
+		if _, err := oldEtcdClient.WaitForClusterAvailable(noDelay, retries, retryInterval); err != nil {
 			fmt.Printf("[upgrade/etcd] Failed to healthcheck previous etcd: %v\n", err)
 			// Nothing else left to try to recover etcd cluster
 			return true, fmt.Errorf("fatal error rolling back local etcd cluster manifest: %v, the backup of etcd database is stored here:(%s)", err, backupEtcdDir)

cmd/kubeadm/app/phases/upgrade/staticpods_test.go

@@ -30,7 +30,7 @@ import (
 	"github.com/coreos/etcd/pkg/transport"
 	"k8s.io/apimachinery/pkg/runtime"
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
-	kubeadmapiext "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1alpha1"
+	kubeadmapiv1alpha1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1alpha1"
 	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
 	certsphase "k8s.io/kubernetes/cmd/kubeadm/app/phases/certs"
 	controlplanephase "k8s.io/kubernetes/cmd/kubeadm/app/phases/controlplane"
@@ -215,20 +215,27 @@ func (c fakeTLSEtcdClient) HasTLS() bool {
 	return c.TLS
 }
 
-func (c fakeTLSEtcdClient) GetStatus() (*clientv3.StatusResponse, error) {
+func (c fakeTLSEtcdClient) ClusterAvailable() (bool, error) { return true, nil }
-	clusterStatus, err := c.GetClusterStatus()
+
-	return clusterStatus[0], err
+func (c fakeTLSEtcdClient) WaitForClusterAvailable(delay time.Duration, retries int, retryInterval time.Duration) (bool, error) {
+	return true, nil
 }
 
-func (c fakeTLSEtcdClient) GetClusterStatus() ([]*clientv3.StatusResponse, error) {
+func (c fakeTLSEtcdClient) GetClusterStatus() (map[string]*clientv3.StatusResponse, error) {
-	client := &clientv3.StatusResponse{
+	return map[string]*clientv3.StatusResponse{
-		Version: "3.1.12",
+		"foo": {
-	}
+			Version: "3.1.12",
-	return []*clientv3.StatusResponse{client}, nil
+		}}, nil
 }
 
-func (c fakeTLSEtcdClient) WaitForStatus(delay time.Duration, retries int, retryInterval time.Duration) (*clientv3.StatusResponse, error) {
+func (c fakeTLSEtcdClient) GetClusterVersions() (map[string]string, error) {
-	return c.GetStatus()
+	return map[string]string{
+		"foo": "3.1.12",
+	}, nil
+}
+
+func (c fakeTLSEtcdClient) GetVersion() (string, error) {
+	return "3.1.12", nil
 }
 
 type fakePodManifestEtcdClient struct{ ManifestDir, CertificatesDir string }
@@ -238,12 +245,13 @@ func (c fakePodManifestEtcdClient) HasTLS() bool {
 	return hasTLS
 }
 
-func (c fakePodManifestEtcdClient) GetStatus() (*clientv3.StatusResponse, error) {
+func (c fakePodManifestEtcdClient) ClusterAvailable() (bool, error) { return true, nil }
-	clusterStatus, err := c.GetClusterStatus()
+
-	return clusterStatus[0], err
+func (c fakePodManifestEtcdClient) WaitForClusterAvailable(delay time.Duration, retries int, retryInterval time.Duration) (bool, error) {
+	return true, nil
 }
 
-func (c fakePodManifestEtcdClient) GetClusterStatus() ([]*clientv3.StatusResponse, error) {
+func (c fakePodManifestEtcdClient) GetClusterStatus() (map[string]*clientv3.StatusResponse, error) {
 	// Make sure the certificates generated from the upgrade are readable from disk
 	tlsInfo := transport.TLSInfo{
 		CertFile:      filepath.Join(c.CertificatesDir, constants.EtcdCACertName),
@@ -255,13 +263,19 @@ func (c fakePodManifestEtcdClient) GetClusterStatus() ([]*clientv3.StatusRespons
 		return nil, err
 	}
 
-	client := &clientv3.StatusResponse{}
+	return map[string]*clientv3.StatusResponse{
-	client.Version = "3.1.12"
+		"foo": {Version: "3.1.12"},
-	return []*clientv3.StatusResponse{client}, nil
+	}, nil
 }
 
-func (c fakePodManifestEtcdClient) WaitForStatus(delay time.Duration, retries int, retryInterval time.Duration) (*clientv3.StatusResponse, error) {
+func (c fakePodManifestEtcdClient) GetClusterVersions() (map[string]string, error) {
-	return c.GetStatus()
+	return map[string]string{
+		"foo": "3.1.12",
+	}, nil
+}
+
+func (c fakePodManifestEtcdClient) GetVersion() (string, error) {
+	return "3.1.12", nil
 }
 
 func TestStaticPodControlPlane(t *testing.T) {
@@ -496,7 +510,7 @@ func getAPIServerHash(dir string) (string, error) {
 }
 
 func getConfig(version, certsDir, etcdDataDir string) (*kubeadmapi.MasterConfiguration, error) {
-	externalcfg := &kubeadmapiext.MasterConfiguration{}
+	externalcfg := &kubeadmapiv1alpha1.MasterConfiguration{}
 	internalcfg := &kubeadmapi.MasterConfiguration{}
 	if err := runtime.DecodeInto(legacyscheme.Codecs.UniversalDecoder(), []byte(fmt.Sprintf(testConfiguration, certsDir, etcdDataDir, version)), externalcfg); err != nil {
 		return nil, fmt.Errorf("unable to decode config: %v", err)

cmd/kubeadm/app/util/etcd/etcd.go

@@ -32,10 +32,12 @@ import (
 
 // ClusterInterrogator is an interface to get etcd cluster related information
 type ClusterInterrogator interface {
-	GetStatus() (*clientv3.StatusResponse, error)
+	ClusterAvailable() (bool, error)
-	WaitForStatus(delay time.Duration, retries int, retryInterval time.Duration) (*clientv3.StatusResponse, error)
+	GetClusterStatus() (map[string]*clientv3.StatusResponse, error)
+	GetClusterVersions() (map[string]string, error)
+	GetVersion() (string, error)
 	HasTLS() bool
-	GetClusterStatus() ([]*clientv3.StatusResponse, error)
+	WaitForClusterAvailable(delay time.Duration, retries int, retryInterval time.Duration) (bool, error)
 }
 
 // Client provides connection parameters for an etcd cluster
@@ -84,54 +86,6 @@ FlagLoop:
 	return true, nil
 }
 
-// GetStatus gets server status
-func (c Client) GetStatus() (*clientv3.StatusResponse, error) {
-	const dialTimeout = 5 * time.Second
-	cli, err := clientv3.New(clientv3.Config{
-		Endpoints:   c.Endpoints,
-		DialTimeout: dialTimeout,
-		TLS:         c.TLS,
-	})
-	if err != nil {
-		return nil, err
-	}
-	defer cli.Close()
-
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	resp, err := cli.Status(ctx, c.Endpoints[0])
-	cancel()
-	if err != nil {
-		return nil, err
-	}
-
-	return resp, nil
-}
-
-// WaitForStatus returns a StatusResponse after an initial delay and retry attempts
-func (c Client) WaitForStatus(delay time.Duration, retries int, retryInterval time.Duration) (*clientv3.StatusResponse, error) {
-	fmt.Printf("[util/etcd] Waiting %v for initial delay\n", delay)
-	time.Sleep(delay)
-	for i := 0; i < retries; i++ {
-		if i > 0 {
-			fmt.Printf("[util/etcd] Waiting %v until next retry\n", retryInterval)
-			time.Sleep(retryInterval)
-		}
-		fmt.Printf("[util/etcd] Attempting to get etcd status %d/%d\n", i+1, retries)
-		resp, err := c.GetStatus()
-		if err != nil {
-			switch err {
-			case context.DeadlineExceeded:
-				fmt.Println("[util/etcd] Attempt timed out")
-			default:
-				fmt.Printf("[util/etcd] Attempt failed with error: %v\n", err)
-			}
-			continue
-		}
-		return resp, nil
-	}
-	return nil, fmt.Errorf("timeout waiting for etcd cluster status")
-}
-
 // New creates a new EtcdCluster client
 func New(endpoints []string, ca, cert, key string) (*Client, error) {
 	client := Client{Endpoints: endpoints}
@@ -169,26 +123,100 @@ func NewFromStaticPod(endpoints []string, manifestDir string, certificatesDir st
 	return New(endpoints, "", "", "")
 }
 
-// GetClusterStatus returns nil for status Up or error for status Down
+// GetVersion returns the etcd version of the cluster.
-func (c Client) GetClusterStatus() ([]*clientv3.StatusResponse, error) {
+// An error is returned if the version of all endpoints do not match
+func (c Client) GetVersion() (string, error) {
+	var clusterVersion string
 
-	var resp []*clientv3.StatusResponse
+	versions, err := c.GetClusterVersions()
-	for _, ep := range c.Endpoints {
+	if err != nil {
-		cli, err := clientv3.New(clientv3.Config{
+		return "", err
-			Endpoints:   []string{ep},
-			DialTimeout: 5 * time.Second,
-			TLS:         c.TLS,
-		})
-		if err != nil {
-			return nil, err
-		}
-		defer cli.Close()
-
-		r, err := cli.Status(context.Background(), ep)
-		if err != nil {
-			return nil, err
-		}
-		resp = append(resp, r)
 	}
-	return resp, nil
+	for _, v := range versions {
+		if clusterVersion == "" {
+			// This is the first version we've seen
+			clusterVersion = v
+		} else if v != clusterVersion {
+			return "", fmt.Errorf("etcd cluster contains endpoints with mismatched versions: %v", versions)
+		} else {
+			clusterVersion = v
+		}
+	}
+	if clusterVersion == "" {
+		return "", fmt.Errorf("could not determine cluster etcd version")
+	}
+	return clusterVersion, nil
+}
+
+// GetClusterVersions returns a map of the endpoints and their associated versions
+func (c Client) GetClusterVersions() (map[string]string, error) {
+	versions := make(map[string]string)
+	statuses, err := c.GetClusterStatus()
+	if err != nil {
+		return versions, err
+	}
+
+	for ep, status := range statuses {
+		versions[ep] = status.Version
+	}
+	return versions, nil
+}
+
+// ClusterAvailable returns true if the cluster status indicates the cluster is available.
+func (c Client) ClusterAvailable() (bool, error) {
+	_, err := c.GetClusterStatus()
+	if err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
+// GetClusterStatus returns nil for status Up or error for status Down
+func (c Client) GetClusterStatus() (map[string]*clientv3.StatusResponse, error) {
+	cli, err := clientv3.New(clientv3.Config{
+		Endpoints:   c.Endpoints,
+		DialTimeout: 5 * time.Second,
+		TLS:         c.TLS,
+	})
+	if err != nil {
+		return nil, err
+	}
+	defer cli.Close()
+
+	clusterStatus := make(map[string]*clientv3.StatusResponse)
+	for _, ep := range c.Endpoints {
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		resp, err := cli.Status(ctx, ep)
+		cancel()
+		if err != nil {
+			return nil, err
+		}
+		clusterStatus[ep] = resp
+	}
+	return clusterStatus, nil
+}
+
+// WaitForClusterAvailable returns true if all endpoints in the cluster are available after an initial delay and retry attempts, an error is returned otherwise
+func (c Client) WaitForClusterAvailable(delay time.Duration, retries int, retryInterval time.Duration) (bool, error) {
+	fmt.Printf("[util/etcd] Waiting %v for initial delay\n", delay)
+	time.Sleep(delay)
+	for i := 0; i < retries; i++ {
+		if i > 0 {
+			fmt.Printf("[util/etcd] Waiting %v until next retry\n", retryInterval)
+			time.Sleep(retryInterval)
+		}
+		fmt.Printf("[util/etcd] Attempting to see if all cluster endpoints are available %d/%d\n", i+1, retries)
+		resp, err := c.ClusterAvailable()
+		if err != nil {
+			switch err {
+			case context.DeadlineExceeded:
+				fmt.Println("[util/etcd] Attempt timed out")
+			default:
+				fmt.Printf("[util/etcd] Attempt failed with error: %v\n", err)
+			}
+			continue
+		}
+		return resp, nil
+	}
+	return false, fmt.Errorf("timeout waiting for etcd cluster to be available")
 }