fix: resolve the issue with Kubernetes upgrade

Add missing cases, refactoring.

Signed-off-by: Alexey Palazhchenko <alexey.palazhchenko@gmail.com>

go.mod

@@ -25,6 +25,7 @@ require (
 	github.com/containernetworking/cni v0.8.1
 	github.com/containernetworking/plugins v0.9.1
 	github.com/coreos/go-iptables v0.5.0
+	github.com/coreos/go-semver v0.3.0
 	github.com/docker/distribution v2.7.1+incompatible
 	github.com/docker/docker v20.10.4+incompatible
 	github.com/docker/go-connections v0.4.0

pkg/cluster/kubernetes/self_hosted.go

@@ -24,15 +24,14 @@ import (
 )
 
 // UpgradeSelfHosted the Kubernetes control plane.
-//
-//nolint:gocyclo
 func UpgradeSelfHosted(ctx context.Context, cluster cluster.K8sProvider, options UpgradeOptions) error {
-	switch {
-	case strings.HasPrefix(options.FromVersion, "1.18.") && strings.HasPrefix(options.ToVersion, "1.19."):
+	switch path := options.Path(); path {
+	case "1.18->1.19":
+		fallthrough
+	case "1.19->1.19":
 		return hyperkubeUpgrade(ctx, cluster, options)
-	case strings.HasPrefix(options.FromVersion, "1.19.") && strings.HasPrefix(options.ToVersion, "1.19."):
-		return hyperkubeUpgrade(ctx, cluster, options)
-	case strings.HasPrefix(options.FromVersion, "1.19.") && strings.HasPrefix(options.ToVersion, "1.20."):
+
+	case "1.19->1.20":
 		options.extraUpdaters = append(options.extraUpdaters, addControlPlaneToleration())
 		options.podCheckpointerExtraUpdaters = append(options.podCheckpointerExtraUpdaters, addControlPlaneToleration())
 
@@ -48,10 +47,16 @@ func UpgradeSelfHosted(ctx context.Context, cluster cluster.K8sProvider, options
 		}
 
 		return hyperkubeUpgrade(ctx, cluster, options)
-	case strings.HasPrefix(options.FromVersion, "1.20.") && strings.HasPrefix(options.ToVersion, "1.20."):
+
+	case "1.20->1.20":
+		fallthrough
+	case "1.20->1.21":
+		fallthrough
+	case "1.21->1.21":
 		return hyperkubeUpgrade(ctx, cluster, options)
+
 	default:
-		return fmt.Errorf("unsupported upgrade from %q to %q", options.FromVersion, options.ToVersion)
+		return fmt.Errorf("unsupported upgrade path %q (from %q to %q)", path, options.FromVersion, options.ToVersion)
 	}
 }
 

pkg/cluster/kubernetes/talos_managed.go

@@ -8,7 +8,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"strings"
 	"time"
 
 	"github.com/talos-systems/go-retry/retry"
@@ -34,13 +33,20 @@ type UpgradeProvider interface {
 //
 //nolint:gocyclo
 func UpgradeTalosManaged(ctx context.Context, cluster UpgradeProvider, options UpgradeOptions) error {
-	switch {
-	case strings.HasPrefix(options.FromVersion, "1.19.") && strings.HasPrefix(options.ToVersion, "1.19."):
-	case strings.HasPrefix(options.FromVersion, "1.19.") && strings.HasPrefix(options.ToVersion, "1.20."):
+	switch path := options.Path(); path {
+	case "1.19->1.19":
+		// nothing
+
+	case "1.19->1.20":
 		options.extraUpdaters = append(options.extraUpdaters, addControlPlaneToleration())
-	case strings.HasPrefix(options.FromVersion, "1.20.") && strings.HasPrefix(options.ToVersion, "1.20."):
+
+	// nothing for all those
+	case "1.20->1.20":
+	case "1.20->1.21":
+	case "1.21->1.21":
+
 	default:
-		return fmt.Errorf("unsupported upgrade from %q to %q", options.FromVersion, options.ToVersion)
+		return fmt.Errorf("unsupported upgrade path %q (from %q to %q)", path, options.FromVersion, options.ToVersion)
 	}
 
 	k8sClient, err := cluster.K8sHelper(ctx)

pkg/cluster/kubernetes/upgrade.go

@@ -5,6 +5,9 @@
 package kubernetes
 
 import (
+	"fmt"
+
+	"github.com/coreos/go-semver/semver"
 	appsv1 "k8s.io/api/apps/v1"
 )
 
@@ -31,4 +34,17 @@ type UpgradeOptions struct {
 	masterNodes                  []string
 }
 
+// Path returns upgrade path in a form "FromMajor.FromMinor->ToMajor.ToMinor" (e.g. "1.20->1.21"),
+// or empty string, if one or both versions can't be parsed.
+func (options *UpgradeOptions) Path() string {
+	from, fromErr := semver.NewVersion(options.FromVersion)
+	to, toErr := semver.NewVersion(options.ToVersion)
+
+	if fromErr != nil || toErr != nil {
+		return ""
+	}
+
+	return fmt.Sprintf("%d.%d->%d.%d", from.Major, from.Minor, to.Major, to.Minor)
+}
+
 type daemonsetUpdater func(ds string, daemonset *appsv1.DaemonSet) error

pkg/cluster/kubernetes/upgrade_test.go

@@ -0,0 +1,39 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package kubernetes_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/talos-systems/talos/pkg/cluster/kubernetes"
+)
+
+func TestPath(t *testing.T) {
+	t.Parallel()
+
+	t.Run("Valid", func(t *testing.T) {
+		t.Parallel()
+
+		options := &kubernetes.UpgradeOptions{
+			FromVersion: "1.20.5",
+			ToVersion:   "1.21.0-beta.0",
+		}
+
+		assert.Equal(t, "1.20->1.21", options.Path())
+	})
+
+	t.Run("Invalid", func(t *testing.T) {
+		t.Parallel()
+
+		options := &kubernetes.UpgradeOptions{
+			FromVersion: "foo",
+			ToVersion:   "bar",
+		}
+
+		assert.Equal(t, "", options.Path())
+	})
+}