Adding etcd version for kubeadm upgrade plan

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

@@ -56,8 +56,10 @@ func RunPlan(parentFlags *cmdUpgradeFlags) error {
 		return err
 	}
 
+	// Define Local Etcd cluster to be able to retrieve information
+	etcdCluster := kubeadmutil.LocalEtcdCluster{}
 	// Compute which upgrade possibilities there are
-	availUpgrades, err := upgrade.GetAvailableUpgrades(upgradeVars.versionGetter, parentFlags.allowExperimentalUpgrades, parentFlags.allowRCUpgrades)
+	availUpgrades, err := upgrade.GetAvailableUpgrades(upgradeVars.versionGetter, parentFlags.allowExperimentalUpgrades, parentFlags.allowRCUpgrades, etcdCluster)
 	if err != nil {
 		return fmt.Errorf("[upgrade/versions] FATAL: %v", err)
 	}
@@ -112,6 +114,7 @@ func printAvailableUpgrades(upgrades []upgrade.Upgrade, w io.Writer) {
 		fmt.Fprintf(tabw, "Scheduler\t%s\t%s\n", upgrade.Before.KubeVersion, upgrade.After.KubeVersion)
 		fmt.Fprintf(tabw, "Kube Proxy\t%s\t%s\n", upgrade.Before.KubeVersion, upgrade.After.KubeVersion)
 		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)
 
 		// 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/constants/constants.go

@@ -226,8 +226,9 @@ var (
 
 	// SupportedEtcdVersion lists officially supported etcd versions with corresponding kubernetes releases
 	SupportedEtcdVersion = map[uint8]string{
-		8: "3.0.17",
-		9: "3.1.10",
+		8:  "3.0.17",
+		9:  "3.1.10",
+		10: "3.1.11",
 	}
 )
 

cmd/kubeadm/app/constants/constants_test.go

@@ -137,8 +137,8 @@ func TestEtcdSupportedVersion(t *testing.T) {
 		},
 		{
 			kubernetesVersion: "1.10.0",
-			expectedVersion:   nil,
-			expectedError:     fmt.Errorf("Unsupported or unknown kubernetes version"),
+			expectedVersion:   version.MustParseSemantic("3.1.11"),
+			expectedError:     nil,
 		},
 		{
 			kubernetesVersion: "1.8.6",

cmd/kubeadm/app/phases/upgrade/BUILD

@@ -78,6 +78,7 @@ go_test(
         "//cmd/kubeadm/app/util/apiclient:go_default_library",
         "//pkg/api/legacyscheme:go_default_library",
         "//pkg/util/version:go_default_library",
+        "//vendor/github.com/coreos/etcd/clientv3:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
     ],
 )

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

@@ -22,6 +22,7 @@ import (
 
 	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
 	"k8s.io/kubernetes/cmd/kubeadm/app/phases/addons/dns"
+	"k8s.io/kubernetes/cmd/kubeadm/app/util"
 	"k8s.io/kubernetes/pkg/util/version"
 )
 
@@ -58,11 +59,13 @@ type ClusterState struct {
 	KubeadmVersion string
 	// KubeletVersions is a map with a version number linked to the amount of kubelets running that version in the cluster
 	KubeletVersions map[string]uint16
+	// EtcdVersion represents the version of etcd used in the cluster
+	EtcdVersion string
 }
 
 // GetAvailableUpgrades fetches all versions from the specified VersionGetter and computes which
 // kinds of upgrades can be performed
-func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesAllowed, rcUpgradesAllowed bool) ([]Upgrade, error) {
+func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesAllowed, rcUpgradesAllowed bool, cluster util.EtcdCluster) ([]Upgrade, error) {
 	fmt.Println("[upgrade] Fetching available versions to upgrade to")
 
 	// Collect the upgrades kubeadm can do in this list
@@ -94,6 +97,12 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 		return nil, err
 	}
 
+	// Get current etcd version
+	etcdStatus, err := cluster.GetEtcdClusterStatus()
+	if err != nil {
+		return nil, err
+	}
+
 	// Construct a descriptor for the current state of the world
 	// TODO: Make CoreDNS available here.
 	beforeState := ClusterState{
@@ -101,6 +110,7 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 		DNSVersion:      dns.GetDNSVersion(clusterVersion, kubeadmconstants.KubeDNS),
 		KubeadmVersion:  kubeadmVersionStr,
 		KubeletVersions: kubeletVersions,
+		EtcdVersion:     etcdStatus.Version,
 	}
 
 	// Do a "dumb guess" that a new minor upgrade is available just because the latest stable version is higher than the cluster version
@@ -111,7 +121,6 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 	// in the case that a user is trying to upgrade from, let's say, v1.8.0-beta.2 to v1.8.0-rc.1 (given we support such upgrades experimentally)
 	// a stable-1.8 branch doesn't exist yet. Hence this check.
 	if patchVersionBranchExists(clusterVersion, stableVersion) {
-
 		currentBranch := getBranchFromVersion(clusterVersionStr)
 		versionLabel := fmt.Sprintf("stable-%s", currentBranch)
 		description := fmt.Sprintf("version in the v%s series", currentBranch)
@@ -143,6 +152,7 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 						KubeVersion:    patchVersionStr,
 						DNSVersion:     dns.GetDNSVersion(patchVersion, kubeadmconstants.KubeDNS),
 						KubeadmVersion: newKubeadmVer,
+						EtcdVersion:    getSuggestedEtcdVersion(patchVersionStr),
 						// KubeletVersions is unset here as it is not used anywhere in .After
 					},
 				})
@@ -158,6 +168,7 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 				KubeVersion:    stableVersionStr,
 				DNSVersion:     dns.GetDNSVersion(stableVersion, kubeadmconstants.KubeDNS),
 				KubeadmVersion: stableVersionStr,
+				EtcdVersion:    getSuggestedEtcdVersion(stableVersionStr),
 				// KubeletVersions is unset here as it is not used anywhere in .After
 			},
 		})
@@ -202,6 +213,7 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 					KubeVersion:    previousBranchLatestVersionStr,
 					DNSVersion:     dns.GetDNSVersion(previousBranchLatestVersion, kubeadmconstants.KubeDNS),
 					KubeadmVersion: previousBranchLatestVersionStr,
+					EtcdVersion:    getSuggestedEtcdVersion(previousBranchLatestVersionStr),
 					// KubeletVersions is unset here as it is not used anywhere in .After
 				},
 			})
@@ -227,6 +239,7 @@ func GetAvailableUpgrades(versionGetterImpl VersionGetter, experimentalUpgradesA
 					KubeVersion:    unstableKubeVersion,
 					DNSVersion:     unstableKubeDNSVersion,
 					KubeadmVersion: unstableKubeVersion,
+					EtcdVersion:    getSuggestedEtcdVersion(unstableKubeVersion),
 					// KubeletVersions is unset here as it is not used anywhere in .After
 				},
 			})
@@ -258,3 +271,12 @@ func rcUpgradePossible(clusterVersion, previousBranchLatestVersion *version.Vers
 func minorUpgradePossibleWithPatchRelease(stableVersion, patchVersion *version.Version) bool {
 	return patchVersion.LessThan(stableVersion)
 }
+
+func getSuggestedEtcdVersion(kubernetesVersion string) string {
+	etcdVersion, err := kubeadmconstants.EtcdSupportedVersion(kubernetesVersion)
+	if err != nil {
+		fmt.Printf("[upgrade/versions] WARNING: No recommended etcd for requested kubernetes version (%s)\n", kubernetesVersion)
+		return "N/A"
+	}
+	return etcdVersion.String()
+}

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

@@ -175,7 +175,8 @@ func performEtcdStaticPodUpgrade(waiter apiclient.Waiter, pathMgr StaticPodPathM
 		return false, fmt.Errorf("external etcd cannot be upgraded with kubeadm")
 	}
 	// Checking health state of etcd before proceeding with the upgrtade
-	etcdStatus, err := util.GetEtcdClusterStatus()
+	etcdCluster := util.LocalEtcdCluster{}
+	etcdStatus, err := etcdCluster.GetEtcdClusterStatus()
 	if err != nil {
 		return true, fmt.Errorf("etcd cluster is not healthy: %v", err)
 	}
@@ -222,7 +223,7 @@ func performEtcdStaticPodUpgrade(waiter apiclient.Waiter, pathMgr StaticPodPathM
 	}
 
 	// Checking health state of etcd after the upgrade
-	etcdStatus, err = util.GetEtcdClusterStatus()
+	etcdStatus, err = etcdCluster.GetEtcdClusterStatus()
 	if err != nil {
 		return true, rollbackEtcdData(cfg, fmt.Errorf("etcd cluster is not healthy after upgrade: %v rolling back", err), pathMgr)
 	}

cmd/kubeadm/app/util/etcd.go

@@ -22,8 +22,16 @@ import (
 	"time"
 )
 
+// EtcdCluster is an interface to get etcd cluster related information
+type EtcdCluster interface {
+	GetEtcdClusterStatus() (*clientv3.StatusResponse, error)
+}
+
+// LocalEtcdCluster represents an instance of a local etcd cluster
+type LocalEtcdCluster struct{}
+
 // GetEtcdClusterStatus returns nil for status Up or error for status Down
-func GetEtcdClusterStatus() (*clientv3.StatusResponse, error) {
+func (cluster LocalEtcdCluster) GetEtcdClusterStatus() (*clientv3.StatusResponse, error) {
 	ep := []string{"localhost:2379"}
 	cli, err := clientv3.New(clientv3.Config{
 		Endpoints:   ep,