wip: don't complain about same-version upgrades

internal/compatibility/compatibility.go

@@ -50,6 +50,17 @@ func (e *InvalidUpgradeError) Error() string {
 	return fmt.Sprintf("upgrading from %s to %s is not a valid upgrade: %s", e.from, e.to, e.innerErr)
 }
 
+// UnnecessaryUpgradeError is returned if both versions are the same.
+type UnnecessaryUpgradeError struct {
+	from string
+	to   string
+}
+
+// Error returns the String representation of this error.
+func (e *UnnecessaryUpgradeError) Error() string {
+	return fmt.Sprintf("no upgrade required from %s to %s", e.from, e.to)
+}
+
 // EnsurePrefixV returns the input string prefixed with the letter "v", if the string doesn't already start with that letter.
 func EnsurePrefixV(str string) string {
 	if strings.HasPrefix(str, "v") {
@@ -67,7 +78,11 @@ func IsValidUpgrade(a, b string) error {
 		return NewInvalidUpgradeError(a, b, ErrSemVer)
 	}
 
-	if semver.Compare(a, b) >= 0 {
+	if semver.Compare(a, b) == 0 {
+		return &UnnecessaryUpgradeError{a, b}
+	}
+
+	if semver.Compare(a, b) > 0 {
 		return NewInvalidUpgradeError(a, b, errors.New("current version newer than or equal to new version"))
 	}
 

internal/constellation/helm/actionfactory.go

@@ -100,6 +100,11 @@ func (a actionFactory) appendNewAction(
 	a.log.Debug(fmt.Sprintf("Current %q version: %q", release.releaseName, currentVersion))
 	a.log.Debug(fmt.Sprintf("New %q version: %q", release.releaseName, newVersion))
 
+	if currentVersion.Compare(newVersion) == 0 {
+		// Nothing to do.
+		return nil
+	}
+
 	if !force {
 		// For charts we package ourselves, the version is equal to the CLI version (charts are embedded in the binary).
 		// We need to make sure this matches with the version in a user's config, if an upgrade should be applied.

internal/constellation/kubecmd/kubecmd.go

@@ -138,12 +138,21 @@ func (k *KubeCmd) UpgradeKubernetesVersion(ctx context.Context, kubernetesVersio
 		))
 	}
 	components, err := k.prepareUpdateK8s(&nodeVersion, versionConfig.ClusterVersion, versionConfig.KubernetesComponents, force)
-	if err != nil {
-		return err
-	}
 
-	if err := k.applyComponentsCM(ctx, components); err != nil {
+	var invalidUpgradeErr *compatibility.InvalidUpgradeError
-		return fmt.Errorf("applying k8s components ConfigMap: %w", err)
+	var unnecessaryUpgradeErr *compatibility.UnnecessaryUpgradeError
+	switch {
+	case err == nil:
+		err := k.applyComponentsCM(ctx, components)
+		if err != nil {
+			return fmt.Errorf("applying k8s components ConfigMap: %w", err)
+		}
+	case errors.As(err, &unnecessaryUpgradeErr):
+		return nil
+	case errors.As(err, &invalidUpgradeErr):
+		return fmt.Errorf("skipping Kubernetes upgrade: %w", err)
+	default:
+		return fmt.Errorf("updating Kubernetes version: %w", err)
 	}
 
 	updatedNodeVersion, err := k.applyNodeVersion(ctx, nodeVersion)